Pests


Adult Asian Citrus Psyllids strike a distinctive pose, angling their backsides up into the air when they feed.

A tiny bug that can carry a deadly citrus disease has been found for the first time in Santa Barbara County — in Santa Maria — and a quarantine may be declared within the next few days.

An Asian Citrus Psyllid was caught last month in a yellow sticky trap hanging from an orange tree in a residential neighborhood three blocks north of the Santa Maria Town Center Mall. The find was confirmed by state agricultural officials this week.

Why the Psyllids are Dangerous

While the psyllids on their own don’t pose much of a problem, they deal a lethal blow to citrus trees if they become infected with a bacterial disease known as citrus greening or huanglongbing (HLB). The disease deforms the fruit, makes it taste bitter, then kills the tree. The devastating disease, which has no cure, was detected in Florida in 2005 and has wiped out more than $1 billion in citrus revenue there. Since then, HLB has marched across a number of southern states, leaving thousands of dead trees in its wake. It reared its ugly head in California earlier this year, infecting a lemon/pummelo tree in Hacienda Heights.

About the size of an aphid, brownish-gray adult Asian Citrus Psyllids mass on the underside of a citrus leaf.

Right now, California Department of Food and Agriculture (CDFA) officials are trying to figure out whether the discovery of the single adult psyllid in Santa Maria was an isolated incident or indicative of a larger problem, according to Brian Cabrera, an entomologist at the Santa Barbara County Agricultural Commissioner’s Office.

“They set out more traps around the area to see how many more there might be, and how much of the area is infested,” Cabrera said. “Based on the results of their survey, they’ll decide what type of quarantine is going to be implemented.”

Choices include a quarantine with a 20-mile radius or a quarantine limited to Santa Barbara County, he said.

In the nymph stage, Asian Citrus Psyllids are dull orange, have red eyes and produce waxy tubules that direct honeydew away from their bodies.

Regardless, a quarantine would ban the movement of any type of citrus — plants, clippings, leaves and fruit — out of the area. The only exception would be commercially grown citrus that meets stringent requirements and receives approved treatment, Cabrera said.

Such a quarantine already exists for a portion of southern Santa Barbara County. After a psyllid was found in La Conchita in Ventura County in 2010, CDFA slapped a 20-mile-radius quarantine around the discovery. The ban is still in effect. It runs from the Ventura County line to Highway 154 and from the coastline high into the foothills, and includes Summerland, Carpinteria, Santa Barbara, eastern Goleta and Painted Cave.

Where Did the Psyllid Come From?

Abnormal fruit produced by

Abnormal fruit produced by a citrus tree infected by Huanglongbing (HLB) or citrus greening disease.

As for how the psyllid made its way to Santa Maria, Cabrera said that if it turns out to be a single find, it’s likely that it arrived as a hitchhiker.

“It was in a residential area, not near commercial orchards,” he said. “Probably someone went into an area in LA County or Ventura County, they got a bag of oranges from one of their family members and a psyllid was attached to one of the leaves. That’s why they call it a hitchhiker.”

But solo or not, ag officials are on high alert, and are actively monitoring sticky traps placed in neighborhoods and commercial groves, parcel carriers like UPS, FedEx and the US Postal Service, and the inventory of various retailers, including big box stores like Costco.

Symptoms of HLB include yellow mottling of the leaves and small, hard fruit with a bitter taste.

Cabrera also encourages homeowners to keep an eye on their citrus trees for any evidence of the psyllids, which are tiny, winged insects that feed on tender, new shoots with their heads down and their bodies angled up at about 45 degrees. The damage may be what’s most apparent — yellow blotches on the leaves and misshapen, bitter fruit.

“Our office is happy to look at any samples. There are so many other things that could cause a citrus leaf to turn yellow,” Cabrera said, adding, “Tell everybody not to move any citrus around.”

Visit Joan’s website at www.SantaBarbaraGardens.com, or post a comment by clicking on “Leave a Comment” back up at the top.

Also please note: If you see an ad below, it has been posted by WordPress to keep the site free. I receive no income from the ad, nor — unfortunately — do I have any control over its content.

Advertisements

Crimson clover is an excellent source of nitrogen, provides forage for beneficial insects and helps control erosion.

If you’re planning to grow only a few vegetables this winter — or even none at all — don’t leave your garden beds bare. Instead, consider sowing a cover crop to rejuvenate your soil.

Sometimes called compost crops or green manure, cover crops have been used for centuries to replenish nutrients, loosen up compacted soil, control erosion, inhibit weeds and provide habitat for beneficial insects.

The technique faded away in the 1950s when the use of fertilizers, herbicides and pesticides became widespread. But with recent interest in organic and sustainable growing techniques, cover crops are enjoying a resurgence in popularity.

Getting Started

Ryegrass helps to break up heavy soil and  control erosion, while fava beans fix nitrogen and attract beneficial insects.

Cover crops come in two flavors: warm-season and cool-season. In all but the largest home gardens, the cool-season types are more practical. That’s because our warm-season summer vegetables tend to take up a lot of room. Think sprawling melon vines, robust rustling cornstalks and bushy, full-bodied tomatoes. Every last square inch of soil is generally consumed by one edible or another.

Come the cool season, many of our crops, including leafy greens, carrots and radishes, can be planted more intensively. Growing these smaller edibles often leaves a fair amount of bare earth, which is perfect for sowing a cover crop.

As for what to grow: consider what you’d like to achieve. Legumes add nitrogen to the soil by grabbing it from the atmosphere and “fixing” it in nodules on their roots. Cool-season annual legumes include clover, vetch, field peas, alfalfa and bell or fava beans.

Grasses and cereal grains help to build the soil and boost fertility by adding organic material. They also improve tilth and fight erosion. While they can look a little straggly themselves, they help to crowd out weeds. Look for annual ryegrass, barley and oats.

Grow a mix if you’d like your cover crop to accomplish more than one of the above. For example, Bountiful Gardens, a mail-order nursery in Willits, California, offers a Compost Crop Mix containing wheat, vetch, rye and fava beans, while Peaceful Valley Farm & Garden Supply, also mail-order, has a Premium Soil Builder Mix composed of bell beans, BioMaster peas, yellow peas, purple vetch, hairy vetch and Cayuse oats.

In the Garden

Planting a blend of wheat, purple vetch and white-blooming fava beans adds nutrients, fixes nitrogen and improves the overall structure of the soil. It’s also pretty enough to harvest for a bouquet.

Cover crops are grown from seed. It’s important to sow the cool-season annual types in September or October while daytime temperatures and soil temperatures are still warm, which boosts germination and gets the seedlings off to a  strong start.

Here’s what to do:

  • Rough up the soil with a stiff rake, garden fork or shovel.
  • Smack any dirt clods to break them apart.
  • Apply a specialized bacteria inoculant to any legume seeds.
  • Scatter the seed at the rate suggested on the packet.
  • Lightly rake in the seed to the recommended depth.
  • Gently water the area.
  • Mulch with a light layer of straw or shredded leaves, then water again.
  • Keep the surface visibly moist for the first week.

Once the seeds sprout, start backing off on the water. As the seedlings begin to shade their own roots, ease off to once a week or so. When winter rains appear, stop watering entirely, unless a dry spell occurs.

Cool-season cover crops typically take five to six months to do their work and should be ready to be knocked down in March or April. But the weather ultimately governs their tenure. They may stall out during several weeks of cooler temperatures and rain, or speed up dramatically with a series of unseasonably warm, dry days.

Harvest Time

Below ground, alfalfa fixes nitrogen. Above ground, it provides excellent habitat for bees.

Regardless of the calendar, your cover crop’s time is up when it begins flowering and its roots are still fresh and pliable.

That point is critical. I once made the mistake of letting fava beans complete their life cycle, including setting seed and withering away. Then, digging into the soil, I discovered thick, fibrous roots. While it’s best to wait three to six weeks between harvesting a cover crop and planting new vegetable seeds or seedlings, no way were those tough ropes of roots going to decompose within a reasonable period of time. To plant new vegetables, I had to yank out the roots, which included their nitrogen nodes. Doing so defeated the purpose of planting the favas. Plus, it was extra work.

To harvest your cover crop, mow it, weed whack it or hack it to the ground. If you’ve grown vetch, trailing peas or any thick-stemmed plants, cut them up so they’ll break down faster. Let the spent pieces dry out for a week or two, then till them into the soil. Or rake up the dried top growth and add it to your compost pile. Later on, you can mix the finished compost into your garden soil, returning all those nutrients and goodness to the earth.

This article was first published in the Fall 2012 issue of Central Coast Farm & Ranch.

Visit Joan’s website at www.SantaBarbaraGardens.com, or post a comment by clicking on “Leave a Comment” back up at the top.

Also please note: If you see an ad below, it has been posted by WordPress to keep the site free. I receive no income from the ad, nor — unfortunately — do I have any control over its content.

Bagrada bugs busy mating on a Brussels sprouts leaf.

A destructive new insect, seemingly out of nowhere, is wreaking havoc on local organic growers and home gardeners.

Over the last six weeks or so, literally hundreds of thousands of Bagrada hilaris bugs have descended on a host of edibles growing in fields across Santa Barbara County and begun methodically sucking the life out of them.

“We lost all the plants in our early plantings of broccoli, cauliflower, anything in the brassica family, Brussels sprouts, all the kale,” said Mark Tollefson, Executive Director of the Center for Urban Agriculture at Fairview Gardens in Goleta. “Over the course of a week, we watched the plants curl up and die.”

Other organic gardeners from Carpinteria to Santa Ynez are suffering losses as well, primarily to members of the brassica family, but also to bok choy, cilantro, peppers and even corn.

“They also are eating weeds, mustard and alyssum. They’re feeding on the plant juices,” said Brian Cabrera, an entomologist at the Santa Barbara County Agricultural Commissioner’s Office. “I have heard that there’s a toxin (in their saliva) that they inject, but I don’t know if they’re actually that toxic to the leaf. I think mainly the damage is from hundreds of these bugs on a single plant, jabbing their little needle-like mouth parts and sucking it dry.”

What to Look For

Bagrada bugs at two stages of life: nymph on the top left; adult on the bottom right.

At first glance, bagrada bugs look like small, dark ladybugs, which of course are fantastic beneficial insects.

But that’s actually their nymph stage, when they’re relatively round, and a two-toned black and red. In a matter of days, they morph to their next stage, in which their bodies elongate and develop distinctive pale, orangish stripes, spots and other marks. Then they begin mating — with the female the larger of the pair — and the cycle begins anew.

In my garden, we first spotted the nymphs on our Brussels sprouts and late-season corn a week ago last Sunday. The adults began emerging a few days later and had begun mating by Friday. We haven’t seen the small, round jelly-like eggs yet, but don’t imagine that it will take long for them to appear. According to Cabrera, a single female can lay about 100 eggs during her lifetime.

Where They Come From

Maria Murrietta, a UC Cooperative Extension agricultural technician, collects Bagrada bugs that have annihilated my Brussels sprouts. The bugs will go to a UC lab for research.

Bagrada bugs are native to east and southern Africa, Egypt, Zaire and Senegal, according to the Center for Invasive Species Research at UC Riverside. They first appeared four years ago in Los Angeles County and rapidly spread through southern California and southern Arizona.

The infestation at Fairview Gardens in mid-August was quickly followed by reports to Cabrera from Solvang, the Mesa, Mission Canyon and other parts of Goleta.

“Then a couple weeks ago, we started getting calls from some of the growers, organic growers especially,” Cabrera said. “They’re getting hit pretty hard. They can’t use some of the materials that the nonorganic growers can use.”

Indeed, conventional farmers are combating — and controlling — bagrada bugs with pyrethroids and organophosphates like chlorpyrifos and malathion, according to Surendra Dara, a strawberry and vegetable crops advisor and affiliated IPM advisor for UC Cooperative Extension for Santa Barbara and San Luis Obispo Counties.

The trouble is, the bugs are so new to scientists that they haven’t yet figured out much in the way of organic controls, Dara said.

Bagrada bugs, scooped up and ready for their trip to the lab.

“Because of the kind of bug it is and its life cycle, it can be a little tricky to develop a strategy to target its vulnerable stages,” he said. “The organic growers, the small gardeners, homeowners, they don’t have resources that farmers have. So for organic farms, you don’t have as many options.”

But that doesn’t mean growers like Tollefson are throwing in the towel. He plans to wait another week before planting another round of cool-season crops. In the meantime, he’ll work through a list of tasks, starting with mixing diatomaceous earth with water, then spraying it on the ground.

“I don’t know the exact pathology, but I do know that bugs that are in contact with it die,” he said. “Bagrada bugs dive into the ground. So sprinkling diatomaceous earth around the soil can be helpful as far as managing them.”

Tollefson also plans to interplant strong-scented garlic and onions with his brassicas, and to wait until his starter plants are 6 to 9 inches tall — instead of just a few inches — before putting them in the ground. His thinking is that the larger plants will be more robust, thereby have a better chance of withstanding the bugs.

Another tactic is to break up the soil. “When temperatures drop below 50 degrees or get very, very hot, the bugs get sluggish. At that point, they stay in the soil,” he said. “Tilling the soil grinds them up. I have a big rototiller. It’s 70 inches wide.”

Weed control is important as well, he said. He might try planting a few sacrificial or trapping crops to intentionally attract the bugs, then kill them “in a natural way.”

Also important is building soil fertility, he added. “The more healthy the plants, the more opportunity we have to beat the bug.”

In Home Gardens

Despite similar markings during their nymph stage, Bagrada bugs are NOT beneficial ladybugs.

For home gardeners whose vegetables are already infested, Cabrera suggested spraying the afflicted plants with a 1% or 2% insecticidal soap solution. In addition, he said, “Vacuuming them off is worth a try.”

For folks who are getting ready to sow their cool-season vegetables from seed, Cabrera recommended turning the soil first, to destroy any eggs, then installing row covers immediately. His advice holds for planting seedlings, too.

“If you determine that your plants are bug-free and egg-free, then put up row covers,” he said. “Make sure that the covers aren’t lying on the plants because the bugs can eat through that. Raise up the covers through hoops or pipes, then bury the edges because (otherwise) the bugs can crawl under.”

As for what lies ahead, Cabrera said, “I don’t know how long they’ll be around. If the weather cools off, the activity will drop off because they don’t seem to be active on cooler days. It remains to be seen within the next few weeks what’s going to happen.”

As far as scientific research into organic controls: Dara is launching a study this week, thanks to scores of bagrada bugs that Maria Murrietta, a UC Cooperative Extension agricultural technician, collected from my ailing Brussels sprouts and corn plants on Friday.

Bye, bye, bagradas. Too bad I couldn’t donate every last one that’s decimating my garden to science!

It was a happy day, to donate so many destructive bugs to science.

Over the new few weeks, Dara will subject those bugs to a mix of products, with the aim of determining whether any organic methods have the potential to successfully control and/or kill the bugs.

In the meantime, Tollefson is philosophical about the challenge.

“So yeah, it’s a big deal to lose these crops,” he said. “But the reality is, it’s one more thing to deal with. It’s significant enough that we can’t ignore it. (But) we’re farmers. We’ll adapt to this bug.”

This article also appears at Noozhawk.com.

Visit Joan’s website at www.SantaBarbaraGardens.com, or post a comment by clicking on “Leave a Comment” back up at the top.

Also please note: If you see an ad below, it has been posted by WordPress to keep the site free. I receive no income from the ad, nor — unfortunately — do I have any control over its content.

Convergent lady beetles at the ARS Beneficial Insects Introduction Research Laboratory in Newark, Delaware.

Stand in the middle of your garden, close your eyes and listen.

Mentally screen out any urban noise — planes overhead, barking dogs, traffic, children — and focus on the natural world. You might hear the hum of honeybees, chirping of birds, wind rustling through leaves or tall grass, or rhythmic drips of moving water.

Those familiar sounds bring a feeling of peace, right?

But take out a magnifying glass and you’ll find that that sense of calm masks a silent war of sorts. On a microscopic level, pests and predators are battling to the death amid the leaves and soil of our gardens.

That’s not a bad thing.

To flip it, predators of pests are actually beneficial. They help keep our gardens healthy by combating pests that might otherwise damage or destroy our crops.

Use of predator insects dates back some 1700 years, when citrus growers in China colonized yellow fear ants to protect against insect pests. The growers linked their trees with bamboo strips so the ants could more easily move from one infestation to the next.

Most of us were introduced to beneficials when we were children, via ladybugs. The cute, round bugs are real charmers. However, their ability to annihilate pests should not be underestimated. Indeed, the importation of Australian ladybird beetles to southern California in the 1880s saved the fledgling citrus industry from a deadly wipeout threatened by cottony cushion scale.

The Big Three

Today, aphids are often the gateway pest that sparks interest in beneficial insects.

Ron Whitehurst, a pest control advisor and co-owner of Rincon-Vitova Insectaries, a company in Ventura that produces and distributes insects and other organisms, supplies and tools for biological control of pests, advises first simply blasting aphids with water. Next up, a soapy solution of an ounce and a half of liquid soap to a gallon of water.

If neither works, he then suggests releasing beneficial insects.

Convergent ladybugs (Hippodamia convergens) are a good start, especially early in the year when other beneficials might not be as active. They are voracious eaters: a single black and orange-spotted alligator-shaped larva may eat 400 aphids before it pupates, while an adult may eat 5,000 aphids during its year-long life.

A green lacewing larva dines on whitefly nymphs.

When temperatures warm up, green lacewings can be even more effective.

The larvae devour not only aphids, but caterpillar pests, eggs and young larvae of Colorado potato beetles, flea beetles, leaf hoppers, mealy bugs, psyllids, scales, spider mites, thrips and whiteflies. As a bonus: unlike ladybugs, green lacewing larvae can’t fly away.

Also, it’s interesting to note that once the larvae mature to gossamer-winged adults, they become vegetarians, supping only on pollen and nectar.

A third aphid-eater Whitehurst recommends is Aphidoletes aphidimyza.

“The mamma Aphidoletes comes around and finds aphids. The baby, a little orange maggot, spears the aphids and sucks them dry and throws them off the plant,” he said. “They tend to colonize. You could do one release, then let them grow and develop.”

Beyond Aphids

To conquer spider mites, thrips, moths and other pests, a second tier of beneficial insects awaits.

“If people are growing lettuces and culinary herbs, spider mites would be one of the things that would be a major pest problem,” Whitehurst said. “From a cultural standpoint, use overhead watering. Spider mites like it hot and dry. So increase the humidity and decrease the temperature to make them less competitive.”

Absent that, he recommends predator mites. Neoseiulus californicus battles spider mites as well as persea mites, which are especially pernicious bugs that suck the chlorophyll from avocado leaves and eventually defoliate the trees.

A minute pirate bug feeds on whitefly nymphs.

Minute pirate bugs (Orius insidiosus) go after western flower thrips, onion thrips and whiteflies.

Or for a one-two punch, Whitehurst recommends Ambleyseius cucumeris, which tackles thrips on the upper part of a plant, and Hypoaspis miles, a soil-dwelling mite that feeds on thrips as they drop on the soil to pupate.

“If you grow a bunch of culinary herbs, it would make sense to inoculate early in the season with those two predator mites to bring down the population of thrips,” he said.

Trichogramma wasps are parasitic insects that lay their eggs within the eggs of over 200 pest moth species. The trichogramma larvae eat the innards of the pest eggs, pupate, then emerge as winged adults, ready to lay ever more eggs. The wasps are especially effective against cabbage caterpillars and worms.

Creating a Habitat

You can grow your own beneficial insects by the way you garden.

“We want to emphasize the whole basic organic or biological approach to gardening,” Whitehurst said. “Focus on feeding the microbes in the soil so the roots on the plants are healthy. Then fertilize with compost and use mulch where appropriate. That will again feed the soil microbes and feed the decomposer insects that feed the predator insects, like the predatory ground beetles and wolf spiders.”

Golden trichogramma wasps parasitizing insect eggs.

Now you don’t have to be a purist. It’s fine to buy beneficials. But to entice them in the first place, or encourage them to stick around after they’ve devoured your pests, sustenance is a must.

The trick is to plant plants that provide a succession of pollen and nectar year-round. The patch can be left a little weedy or wild, and should never be sprayed.

“Dill is a real champ as far as having this umbel-shaped flower that has nectar available to big insects and little insects,” Whitehurst said. “Several others in the Apiaceae family are fennel, cilantro and anise. You can grow more moderate versions. Ornamental bronze fennel is a little more reserved than the wild fennel.”

Other herbs to sustain beneficials include angelica, anise hyssop, borage, caraway, chamomile, marjoram, oregano, parsley, sage, teucrium, thyme and yarrow.

Native plants include milkweed (Asclepias), saltbush (Atriplex), coyote brush (Baccharis), wild lilac (Ceanothus), buckwheat (Eriogonum), toyon (Heteromeles), bladder pod (Isomeris) and coffeeberry (Rhamnus).

A handful of miscellaneous plants includes golden marguerite (Anthemis tinctoria), bell beans, black-eyed peas, bachelor’s buttons (Centaurea cyanus), corn, cosmos, sweet alyssum (Lobularia maritima), yellow sweet clover (Melilotus officinalis), sunflowers and white clover (Trifolia repens).

Lending a Hand

An adult assassin bug, Zelus renardii, feeds on a Lygus bug, which disfigures and damages strawberries.

After you’ve built up an ecosystem and colonized beneficials in one spot, it’s easy to move them to wherever trouble is brewing by spraying an attractant.

For instance, if aphids are massing on your broccoli, Whitehurst advises the following.

“Mix equal parts sugar and dried brewers yeast. Add water. Then spray large droplets, widely scattered. That simulates the situation where you have plants that are real sticky with honeydew. That will draw in the lacewings and ladybirds and syrphid flies and such… It’s pretty effective as far as drawing in the aphid predators.”

Helping Combat the Enemy

While beneficial insects dominate their prey, they are vulnerable to ants.

“Ants collect the honeydew, the sugary poop from aphids, whitefly, scale,” Whitehurst said. “If they’re working the plants, they will be collecting that honeydew and driving off the beneficial insects that are trying to eat the pests that are generating their candy.”

Controlling ants, then, is an important aspect of supporting and maintaining your beneficials. Whitehurst recommends buying or mixing up a borate-based bait. The ants will eat the bait, take it back to their colonies and perish.

Thanks to the California Department of Food & Agriculture for providing these photos.

A slightly condensed version of this article was first published in Edible Santa Barbara.

Visit Joan’s website at www.SantaBarbaraGardens.com, or post a comment by clicking on “Leave a Comment” back up at the top.

Also please note: If you see an ad below, it has been posted by WordPress to keep the site free. I receive no income from the ad, nor — unfortunately — do I have any control over its content.

If you don't already, learn to appreciate gopher snakes.

Earth Day festivities are set for this week throughout the county and the country.

But you can celebrate the occasion year-round in the garden by following a few simple techniques.

The following ideas are easy on the natural world. Some require a little effort. Others might be considered downright lazy.

What they all share is the goal of conserving resources while creating a healthy environment for your plants and the creatures that inhabit your garden.

You can call it ecological, environmental, sustainable or green gardening. But by whatever measure, also please call it common sense.

Fix Those Drips

Stop that drip!

Sooner or later, it seems that most outdoor faucets leak. Aside from the wasted water, a mucky wet spot right up against your house is not good.

Depending on your skills, you can fix the leak yourself or call a plumber.

If the faucet handle spurts only when you turn on the water, the lazy way out is to place a bucket beneath and use the water to irrigate potted plants.

Sometimes it’s not the faucet, but the hose connector. Rather than tossing the hose, replace the connector.

If repairs aren’t in the offing, plant a bog plant under the faucet so that the leak isn’t a complete waste.

Depending on the size of the seep, pretty California native perennials to consider include western columbine (Aquilegia formosa), wild ginger (Asarum caudatum), stream orchid (Epipactis gigantea), scarlet monkeyflower (Mimulus cardinalis) and Point Reyes checkerbloom (Sidalcea calycosa ssp. rhizomata).

Automate

Taller pop-up sprinklers water this swath of California meadow sedge (Carex praegracilis).

Watering by hand, hauling hoses and moving portable lawn sprinklers gets old quickly. It’s tedious, inefficient and has the potential to waste an incredible amount of water.

Instead, install drip irrigation in your flower beds and around shrubs and trees; and pop-up sprinklers for your ground covers and lawn.

Then install an irrigation controller to automate the system. If you have water-conserving plants that need water every two to three weeks, make sure your timer can accommodate that long of an interval. Some inexpensive controllers only allow intervals of up to a week.

Just because you have a controller doesn’t mean you can ignore it. For instance, if May and June are damp and foggy, your plants won’t need much water. But if clear, windy days persist, they’ll want more.

Regardless of whether you automate or stay manual, water early in the morning, before the wind kicks up. This minimizes evaporation, gives your plants a fresh start and helps reduce fungal diseases that can take hold if the foliage is wet at night.

Fight Bugs Naturally

They may foul your eaves, but cliff swallows eat mosquitoes, too.

Avoid using bug spray as your first line of defense.

If aphids are a problem, hose them off with a blast from your hose. Or release lady bugs or green lacewings to gobble them up. If aphids are infiltrating your late-season broccoli, plant green onions nearby.

Marigolds, calendulas and nasturtiums are also excellent companions. In the vegetable garden, they’ll help to deter bean beetles, cabbage pests, nematodes, tomato hornworms, asparagus beetles and squash bugs.

If giant white fly is a problem, try mulching with cocoa hulls and spraying the undersides of the affected plants with horticultural oil or a mild dilution of powdered dish soap.

Cliff swallows will make a mess as they build their mud nests in your eaves. But they eat mosquitoes by the thousands.

Gopher snakes may appear alarming. But leave them alone. They’ll help keep underground rodents from tearing up your garden. And unlike gopher gas and other poisons, they won’t hurt the environment.

Start a Compost Bin

Yum! Kitchen scraps and a few rose leaves destined for my compost pile.

Compost does wonderful things in the garden. It provides nutrients in an easily accessible form to plants and promotes the growth of beneficial microorganisms in the soil.

You can buy bags of compost or create your own.

Three things go into my compost bins: kitchen scraps, yard waste and leftover potting soil.

Kitchen scraps are fruit and vegetable waste — apple cores, onion peels, celery stalks, leafy greens and the like. Don’t use meat and dairy scraps. They’ll go rancid. I collect the scraps in a stainless pot with a tight-fitting lid, then mix the contents into my outdoor compost bins once or twice a week.

Yard waste is a combination of green (nitrogen) and brown (carbon) material. The green is mostly grass clippings, while the brown is crumpled leaves, plus debris swept off the driveway and patio.

I occasionally add water, which seems to help speed the decomposition. Be sure your bins are in a sunny spot. The pile needs to build up heat to break down the various materials. Relegated to the shade, the process can literally take years.

Mulch Clippings

A light layer of both fresh and dried glass clippings is a healthy mulch for these variegated iris (Iris pallida 'Variegata'), bloody cranesbill (Geranium sanguineum) and soon-to-bloom yellow Coreopsis.

Don’t throw away your lawn clippings. They contain valuable nutrients. Instead, put them to work in your garden.

You can use a mulching mower, which chops the grass blades even finer than a regular mower, then deposits the cuttings back on the lawn.

If your lawn is purely for show, that’s great. But if you have kids or animals romping across with wet feet, they’ll track those little blades everywhere.

Instead, mulch your flower beds with a thin layer. if the clippings are too thick, the blades will mat together and begin to smell.

Or dump the clippings in your compost pile. Mix them well with the other contents, so that they don’t bind together and form an impenetrable block.

Freshen Mulch

A thick layer of gorilla hair mulch softens the angular effect of these foxtail agaves (Agave attenuata).

Two to 3 inches of grass clippings can make a slimy mess. But several inches thick of loose, organic material, such as walk-on bark, will conserve moisture, moderate the soil temperature and help reduce weeds.

Plus, it looks nice, smells good and provides a consistent look to the landscape.

I’ve had a few clients complain that mulch is a waste, because it disappears. But that’s actually a good thing. That “disappearance” means the mulch is breaking down, releasing nutrients to the plants and improving the texture of the soil.

Weed By Hand

A bulky layer of mulch will inhibit weed seeds that need light to germinate. But other opportunistic weeds will still come through.

Rather than killing the weeds with chemical sprays, set aside time to pull the weeds by hand. Try to get the weeds before they set seed. If I see flowers forming and am short on time, I’ll use kitchen scissors to snip off the heads, then go back later to dig out the leafy parts and their roots.

Use caution if you resort to using a “weed and feed” product on your lawn. The “weed” portion of the equation contains chemicals that may be harmful to kids or animals that play too soon in the area.

Fertilize Naturally

Bu's Blend Biodynamic Compost.

Whether it’s in liquid or granular form, or slowly released from fluffy compost or humus, use natural or organic fertilizer as much as possible.

It’s much kinder to the soil, as well as to earthworms, birds, butterflies and other wildlife.

Look for products that contain beneficial soil bacteria such as mycorrhizae, compost, guano, humic acid or humus (compost that has broken down past the fibrous state).

With increasing interest in “green” products, mainstream lawn and garden chemical companies are now offering natural products, too.

Also look for organics that are OMRI listed. The Organic Materials Review Institute tests products intended for use in certified organic production, handling and processing. The OMRI seal means that what you’re buying complies with USDA organic standards.

Choose Your Battles

A striped monarch butterfly caterpillar begins to devour the tasty leaves of a butterfly weed (Asclepias curassavica).

Sometimes a few defoliated plants are worth the effort to attract wildlife.

In my garden, I willingly sacrifice butterflyweed (Asclepias curassavica) in order to fortify the fat, yellow-striped monarch butterfly caterpillars that somehow know to appear just when the yellow, orange and red flowers are beginning to bloom.

A few years back, little cottontail bunnies nibbled away all my seedling melons. Rather than fighting the gray fluffballs, I planted another round in a raised bed that they couldn’t reach.

But even I have my limits. When slugs and snails begin to defoliate my roses, I draw my line in the sand with Sluggo, a natural granular product containing iron phosphate, which is safe to use around pets and wildlife. This year I’m also planning to try a new foliar spray from Gro-Power called Snail & Slug Away. It’s nontoxic, organic and lists cinnamon oil as its active ingredient. Maybe it even smells good.

Seeds of Wisdom

If you’re encouraging birds, butterflies and other wildlife to visit your garden, go pesticide free. Otherwise you risk administering a dose of toxic chemicals when the critters forage among your flowers.

Visit Joan’s website at www.SantaBarbaraGardens.com, or post a comment by clicking on “Leave a Comment” back up at the top.

Also please note: If you see an ad below, it has been posted by WordPress to keep the site free. I receive no income from the ad, nor do I have any control over its content.

An adult Asian citrus psyllid, bottom up.

After several years of wary anticipation, the dreaded citrus greening disease, huanglongbing (HLB), has been found in southern California. And that has put officials in Santa Barbara County — and throughout the state — on high alert.

The devastating disease was detected in Florida in 2005, and has wiped out $1.3 billion in citrus revenue there. Since then, HLB has marched across a number of southern states, leaving thousands of dead trees in its wake.

HLB is carried by the Asian citrus psyllid. Occasional psyllids have been found in back yard gardens and commercial groves in California over the past few years. I first wrote about the threat in September 2009 (see below). Since then, the closest to Santa Barbara County that psyllids have been found has been in La Conchita and Santa Paula.

The afflicted tree in Hacienda Heights.

Not all Asian citrus psyllids transmit the disease, and up to this point, none proved to be a carrier.

But the infected lemon/pummelo tree found in Hacienda Heights is a real game changer.

It’s the first citrus tree to test positive for HLB in California. Psyllids found in the same neighborhood tested positive for the disease as well.

The tree has since been dug out and moved to a state lab for further testing.

State agriculture officials say they plan to “conduct treatment of citrus trees within 800 meters of the find site,” although what that treatment will be has not yet been revealed.

What is known is that there’s still no cure for the deadly disease.

What’s Next?

Locally, Santa Barbara County agriculture officials hope to prevent HLB from infecting Central Coast citrus trees through a quarantine, inspections and help from the public.

For now, a quarantine put into place in December 2010 is still in effect for southern Santa Barbara County.

The area runs from the Ventura County line to Highway 154, and from the coastline high into the foothills. It includes Summerland, Carpinteria, Santa Barbara, eastern Goleta and Painted Cave. No citrus of any type — no plants, clippings, leaves or fruit — is to be transported out of the quarantine area.

Strictly speaking, this means that if you live within the quarantine area and work in the western end of Goleta, you shouldn’t even pack a home-grown orange in your lunch.

The state has set up similar quarantines in Ventura, Imperial, Los Angeles, Orange, Riverside, San Bernardino and San Diego Counties.

What to Look For

Asian citrus psyllids are tiny, winged insects that feed with their heads down and their bottoms angled up at about 45 degrees.

Asian citrus psyllids typically lay their eggs on the newest, most tender, unfolded leaves.

They produce tiny, bright, golden-yellow eggs, while the nymphs are dull orange and nearly impossible to see with the naked eye.

The damage that they cause is far more evident: yellow blotches on the leaves and misshapen, not-too-tasty fruit. Indeed, the Hacienda Heights tree had those yellow mottled leaves.

The trouble is, other diseases can cause similar symptoms.

If you suspect something is wrong with any of your citrus trees, take a sample to the county agriculture commissioner’s office. Instructions are listed below.

Here’s what I wrote back in September 2009. Dramatic then, perhaps, but even more so today.

Imagine a day with no fresh-squeezed orange juice. No lemon zest. No slices of lime. No sweet Satsuma tangerines. No citrus of any kind.

That’s a doomsday that California agricultural officials are trying to prevent. And they’re looking for help from everyone who grows citrus trees — from a singe lemon planted in a pot on a patio, to the largest commercial groves in the state.

All citrus — oranges, lemons, limes, grapefruits, mandarins, tangerines, tangelos, kumquats, citrons, pomelos and the like — are at risk, as well as closely related ornamental plants, such as orange jasmine (Murraya paniculata), cape chestnut trees (Calodendrum capensis) and culinary curry leaves (Murraya koenigii), which may be shipped in from Hawaii or India.

The Threat

An adult Asian citrus psyllid. Even the adults are so tiny that they're nearly impossible to see without a magnifying glass.

The threat starts with the Asian citrus psyllid. On their own, the tiny insects don’t cause irreparable damage.

But they deal a lethal blow to citrus trees when they become infected with Huanglongbing (HLB), a devastating bacterial plant disease that’s also known as citrus greening disease.

Essentially, the disease deforms the fruit and makes it tastes bitter, then kills the tree.

There is no cure.

“The combination of the Asian citrus psyllid and the disease has the greatest potential to impact citrus growing in California of anything I’ve ever seen,” said Bill Gillette, Santa Barbara County Agricultural Commissioner. “The reason for that is that the Mediterranean fruit flies, the other fruit flies, we can get rid of. This one, they haven’t been able to stop it anyplace yet, and it actually kills the trees.”

The deadly duo has ravaged groves around the world, including Asia, India, Egypt, Africa and Brazil. The disease was discovered in Florida in September 2005, and has since spread throughout the state, taking a serious bite out of Florida’s $9.3 billion juice industry. HLB has also been detected in South Carolina, Georgia, Louisiana, Belize and the Yucatan Peninsula.

An infestation of adult Asian citrus psyllids.

Meanwhile, the psyllids — not yet carrying HLB, as far as anyone knows — are moving into California. They were first reported in groves in San Diego and Imperial Counties in August 2008. Last week, they showed up in Santa Ana on a lemon tree, and in Echo Park on a calamondin tree, which bears small, tangy orange fruit. Quarantines are in effect everywhere the psyllids have been found, including all 800 square miles of Orange County.

A serendipitous finding of the dreaded Huanglongbing occurred in July — although not on a live tree. Instead, an agricultural inspection “sniff dog” at a FedEx facility in Fresno found a duffle bag shipped from India that carried curry leaves and infected psyllids.

Another sniff dog, this one last week at a FedEx depot in Sacramento, detected psyllids inside a package from Texas containing guavas and curry leaves. Fortunately, none of those psyllids tested positive.

“No one can say for sure if the disease will ever get here (to Santa Barbara County),” said Gillette. “One, you hope it doesn’t, but it’s likely it will. Then two, you hope it isn’t going to have the same effect on citrus in this area. But I think that’s pretty naive.”

The Symptoms

According to the California Citrus Research Board, the nymphs are dull orange, have red eyes and produce waxy tubules that direct honeydew away from their bodies.

At 3 to 4 millimeters in length at maturity, Asian citrus psyllids are so tiny, even the experts can have trouble detecting them.

“When I spoke with the entomologist in San Diego County, he said they were really hard to see,” said Brian Cabrera, Santa Barbara County Entomologist.

“Several people, all experts, were looking for the insects. They all looked but couldn’t find them. Then they vacuumed the leaves, and they actually found the psyllid that way.”

So rather than searching for psyllids, Cabrera said, homeowners should look for their damage. Asian citrus psyllids feed on new stems and leaves. That’s why agricultural officials are on high alert now, since citrus trees push out new growth between late summer and early winter.

Psyllids that aren’t infected with greening disease can still harm leaves, Cabrera said. “Their saliva actually has some toxicity to cause the leaves to curl. (And) they produce a tiny amount of wax.”

But the damage is far worse once the disease strikes.

Characteristic yellow mottling of the leaves.

“Homeowners should look for anything suspicious with their trees, any sudden decline in the trees, any abnormalities, or yellowing of the leaves,” Cabrera said. “The fruit is abnormal, lopsided and bitter. The leaves have a twisted, gnarled, deformed look.”

Also, according to the California Citrus Research Board, “As HLB progresses, leaves and whole branches fall off the tree and eventually the entire tree dies.”

Unfortunately, identification is tricky because plenty of other pests, diseases and mineral deficiencies create the same symptoms. For instance, chlorosis, a common iron deficiency in citrus, also causes yellowing leaves.

“The main problem is that the symptoms are not diagnostic,” said Heather Scheck, Santa Barbara County Plant Pathologist. She sends questionable leaves to a lab in Sacramento for molecular testing. “It could also be a nutritional problem. It could be another disease, viral, bacterial or fungal. That’s what happened in Florida. They probably had it in for a long time. It wasn’t until they did the actual testing that they discovered they had citrus greening disease.”

What to Do

HLB-infected trees produce lopsided, misshapen fruit.

County agricultural officials urge anyone who suspects that their plants are being harmed by any type of insects or disease, not just Asian citrus psyllids or citrus greening, to collect samples for testing. The service is free.

“One of our missions is to reduce pesticide use. We accomplish that by giving accurate diagnosis,” Scheck said. “You don’t want to hear that someone has sprayed and sprayed, only to discover that it’s a virus or nutritional thing.”

Insect samples should include both the insects and a few damaged leaves, while suspicious stems and leaves should be on branches at least 18 inches long.

Two of the agricultural commissioner’s offices accept walk-ins between 8 a.m. and 4:30 p.m., Monday through Friday: 624 W. Foster Rd., Santa Maria, 934-6200; and 263 Camino del Remedio, Santa Barbara, 681-5600. Or make an appointment to leave samples at 121 N. G St., Lompoc, 737-7733; or 1745 Mission Dr., Solvang, 686-5064.

In addition, the California Department of Food and Agriculture (CDFA) has added the Asian citrus psyllid to its residential trapping program, which is how the psyllids were discovered in Santa Ana and Echo Park. Here in Santa Barbara County, CDFA technicians based in Buellton set traps in neighborhoods, parks and business centers countywide.

“Non-indigenous fruit flies are our main deal. Mediterranean, Mexican, Oriental and melon flies. We also do the light brown apple moth, Asian citrus psyllid and false coddling moth. That’s what we’re trapping for now,” said Jay Burwell, a CDFA Agricultural Technician III. “Right now, we have 368 locations. But that fluctuates highly for seasonal host availability.”

Yellow sticky cards are the trap of choice for the Asian citrus psyllid, which Burwell’s office sends to Sacramento for testing and identification.

“The problem is, there are so many psyllids,” he said. “If there were only one type of psyllid, it would be easy to detect.”

Stop the Transport

Because there is no cure for Huanglongbing (HLB) or citrus greening disease, the only way to prevent the deadly disease is to avoid transporting citrus trees, citrus fruit and closely related plants, such as orange jasmine, cape chestnut trees and curry leaves.

According to the US Department of Agriculture, “The safest approach is simply to not move citrus plants, ship citrus plants, or buy host citrus plants online unless you are absolutely sure the plant is not from an area that is quarantined for either citrus greening disease or Asian citrus psyllids.”

Santa Barbara County Agriculture Commissioner Bill Gillette echoes those thoughts.

“The message for everybody isn’t so much this particular insect as it is for all fruits and vegetables, whether you’re dealing with Oriental fruit flies or the light brown apple moth or Asian citrus psyllids. Those generally don’t get here by themselves,” he said.

“These types of things, certainly the disease, that’s how it’s going to get in here. Somebody’s going to either inadvertently or smuggle some infected plant material in here. Then we’ve got a problem.”

Useful Websites

To learn more about the Asian citrus psyllid and Huanglongbing (HLB) or citrus greening disease, read prevention tips, and view photos of the psyllid and the damage it can cause, visit:

The Citrus Research Board
californiacitrusthreat.com

California Department of Food & Agriculture
cdfa.ca.gov/phpps/acp/

UC Agriculture and Natural Resources
http://ucanr.org/sites/KACCitrusEntomology/Home/Asian_Citrus_Psyllid/

US Department of Agriculture
saveourcitrus.org

Seeds of Wisdom

If you suspect any problem with your citrus trees, especially on new growth, take a sample to an office of the county agricultural commissioner for a diagnosis or call the state pest hotline, (800) 491-1899.

Visit Joan’s website at www.SantaBarbaraGardens.com, or post a comment by clicking on “Leave a Comment” back up at the top.

Also please note: If you see an ad below, it has been posted by WordPress to keep the site free. I receive no income from the ad, nor do I have any control over its content.

California oakworm

“Attack of the Oakworms!” may never make it as a science fiction movie. But the concept is playing out in real life throughout the Central Coast.

Take a drive, and you’ll find that our early, spring-like temperatures are encouraging all sorts of deciduous trees to leaf out in fresh green.

Yet the coast live oaks (Quercus agrifolia) are behaving like it’s opposite day, losing their leaves and looking like brown skeletons looming over the landscape.

Get up close to any coast live oak that still has leaves, and you’ll see inch-long California oakworms (Phryganidia californica) munching through every last bit of foliage.

The voracious eaters devour the stiff, prickly leaves, methodically moving from one tree to the next.

The relentless march began in my coastal canyon neighborhood a couple of months ago. It has slowly proceeded up the canyon, only recently reaching our trees. The first sign was some browning at the tips. Now, amid a sprinkling of spring’s usual new leaves and pollen tassels, are brittle, twiggy branches, stripped of life.

And then there were two...

Apparently heaviest infestations can be tied to uncommonly warm, dry winters, which could explain our current outbreak.

Unfortunately, there’s not a whole lot we can do about the worms, other than to simply wait them out.

There’s no spray or treatment that will magically eliminate them. Instead, they’ll eventually morph into fluttery, dove-gray moths that can be annoying as well.

But despite the frustration of seeing our beautiful trees defoliated, the devastation will not last forever. The word from local arborists is that healthy oaks should rebound without serious harm.

Visit Joan’s website at www.SantaBarbaraGardens.com, or post a comment by clicking on “Leave a Comment” back up at the top.

Also please note: If you see an ad below, it has been posted by WordPress to keep the site free. I receive no income from the ad, nor do I have any control over its content.

Next Page »