Wednesday, July 28, 2010

What Plant Is Your Horse Eating Right Now?

 A caller to the radio program awhile back asked a good question, one that livestock-owning country dwellers ought to also consider:
     "I want to plant some trees or shrubs that will grow quickly to hide the view of a new house going in next to us," said the caller. "But I don't want to plant anything that might be poisonous to our horses, which will eat just about anything. Any ideas?"

    "There definitely are some plants that you should avoid," advises Dr. Frank Galey, now with the University of Wyoming, formerly the toxicologist at the California Veterinary Diagnostic Laboratory Systems at UC Davis. 
Highly poisonous plants that should not be planted within the reach of horses include:
The book, "The UC Davis Book of Horses", says that the oleanders (of which all parts are toxic) can cause horses to develop diarrhea, colic and an irregular heartbeat.

"A yew can kill a pile of horses in a heartbeat," says Dr. Galey.


Rhododendrons and azaleas, which can cause severe colic or diarrhea, can often be found while on wilderness expeditions with your horses. They will be become hungry during prolonged treks and may eat any forage available at rest stops or campsites. A good piece of advice? Don't picket your horse near any shrubs.

                                Privet with berries

 There are many, many more plants that can be toxic to horses, a list of which you can probably get from your veterinarian. "Toxic" has a wide meaning, from gastric distress to death. Among the other highly toxic plants that are commonly found in California: 

the twigs and leaves of deciduous fruit trees, including apricot, cherry, peach and plum;
Mountain Laurel
Oak acorns (in large quantities)
Sweetpea seeds
Tomato vines



There are a number of trees and shrubs that can provide a quick screening effect; here are a few that will do well in our area of California and are the least toxic to horses:

* Eucalyptus. "Horses tend to leave eucalyptus trees alone," says Dr. Galey. For a quick, bushy screen, plant the Eucalyptus globulus 'Compacta', the dwarf blue gum, about six feet apart.

* Bottlebrush (Callistemon citrinus). This evergreen shrub can reach 15-20 feet tall, and is dotted with colorful, bright red bottlebrush-shaped flowers several times throughout the year. "We haven't had any poison reports about the bottlebrush, so it should be pretty safe," says Dr. Galey. "But because the plant attracts bees, it's possible the horse could be allergic to bee stings."

* Coast redwood (Sequoia sempervirens). Given ample water, this evergreen tree can grow several feet a year. It also has a low incidence of toxicity. Horses, though, may trample the lower branches.

     It's up to the horse owner to be vigilant, patrolling the pasture regularly for unfamiliar plants, especially those that may pop up seasonally. Look for toxic plants near water tanks or ponds; along fence rows; or, roadside gullies that a hungry horse might reach.

    This word of caution: anything eaten in mass quantities by a horse may cause medical problems. A good book that goes much more in depth on this topic is
"The Horse Owners Field Guide to Toxic Plants". And check your horse insurance policy. Make sure you have thorough coverage if your pasture is surrounded by a field full of mystery plants. Some companies may drag their feet if the horse is suffering due to human error.
So, if you have horses that have never missed a meal, you may want to install a horse fence or hot wire between the screening plants and your ravenous friends.

Monday, July 26, 2010

Which Mulch is Best for You? 2010 Update

Adding a three to four inch layer of mulch now beneath shrubs and trees, out to the drip line, can help stop weeds, keeps the ground evenly moist and feeds the plants as well. But which mulch is best?
Each type of mulch has its Pros and Cons:

Bark: lasts a long time, looks nice, feeds the soil slowly, suppresses weeds. Beware of finely shredded redwood bark: the hairs can easily ignite if someone tosses in a cigarette butt.
  Medium to large bark stays in place better than the mini-bark. Buy bark bulk from a sand and gravel yard to save money. It may seem like a lot of bark, but you'll find a place to use it!

Cocoa shells: look nice, last a long time, but some varieties may be toxic to dogs, due to the potential of theobromine poisoning.

Chipped/Shredded tree trimmings: inexpensive, feeds the soil, supresses weeds, but needs to be replenished yearly.  In the good old days, you could bribe a tree trimming company doing work on your street to drop off their load in your yard; after all, they were probably just going to take it to the dump. Not any more. Due to the demand of this as a mulch, many arbor companies are keeping or reselling chipped/shredded tree trimmings. Still, it can't hurt to ask! However, consider this: you may be importing someone else's plant pests or diseases into your yard. One way to mitigate this: keep those trimmings in a pile for several months. That can help to destroy pest eggs and certain pathogens, if the temperature in the pile gets up to 140 degrees or so. The downside of keeping tree trimming in a large pile: ant colonies might move in. Be careful when shoveling!

Pine needles: best spread about three inches deep around acid loving plants.
Don't let it get too thick though. It might block the transfer of air and water into the soil, creating an anaerobic environment.

Compost: Inexpensive (if home made), provides soil nutrients and improves soil structure. But weed seeds can germinate in it.
And, it needs to be replenished every year.

Grass Clippings: inexpensive, but should be applied when thoroughly dried. Also, clippings from weed-like grasses, such as bermudagrass, may get established in other areas. And, don't use grass clippings from a lawn that has been treated with weed killers; in particular, postemergent selective herbicides. This could harm the roots of desirable plants.

Straw: Not to be confused with alfalfa, which can germinate if used as a mulch. Keeps weeds down, retains soil moisture, adds nutrients as it breaks down. Can be bulky to transport in bales (get bale hooks!). A good mulch for walkways, too. Ruth Stout wrote entire books on the subject of using straw mulch in the garden. They're collector's items now.

Leaves: Why do you think God named them "leaves"? "Leave" 'em be, where they fall. Better yet, shred the leaves with a bagging lawn mower to create a quicker nutrient source for your flower beds and borders. They break down quickly, so leaves must be constantly added to an area.

Worm Castings: The Master Composters at Texas A&M University do not recommend using worm castings as a mulch. Worm castings, they report,  are too nutrient-rich to use as mulch on outdoor plants; they tend to dry out and the nutrients are wasted

Permeable Weed Cloth: Not recommended by Washington State University. It is inorganic, suppresses weeds while allowing air and water to pass through. Needs a layer of bark on top to keep it from disintegrating from sunlight. May keep soil too moist. May lead to surface rooting of plants. Pulling up weeds that are growing in weed cloth may pull up portions of the cloth as well.

Newspapers: inexpensive, suppresses weeds. Must be replaced often, needs to be secured in place.

Plastic: Suppresses weeds, but does not allow air or water to pass through. In the summer, it may raise soil temperatures too high. Needs to be secured to the soil.

Rock: Looks good, but provides no nutrients, may raise soil temperatures, damaging shallow plant roots.

Benefits of organic mulch:
• retains moisture
• keeps soil temperature constant, reducing plant stress
• suppresses weeds
• gradually increases soil organic matter
• attracts beneficial organisms that improve soil fertility and porosity.
• mulch encourages healthier plants, reducing the needs for pesticides and fertilizers.
• protects roots and plants from mechanical injury.
• on hillsides and around homes, it suppresses the spread of brush fires.

Some cautionary notes: 

• Don't pile up organic mulch around the trunks of trees and shrubs. 

• Keep mulch a few inches away from trunks to lessen the chances of rots and other diseases.
• Don't import someone else's problems. Avoid using as mulch any diseased plant material, including suffering tree limbs, diseased leaves, herbicide-treated lawn.

To cover an area with three inches of mulch:
apply about 1 cubic yard for every 100 square feet of area.

One of the downsides of mulch: native bees will be dissuaded from nesting in mulched areas. To attract ground-dwelling native bees, keep a portion of your yard unmulched.

For a great publication about mulch, download this pdf, "The Landscapers' Guide to Mulch" from the California Integrated Waste Management Board.

And, the video, Mulch Madness!

Friday, July 23, 2010

The Green Fruit Beetles Return in 2010

     While searching for ripened tomatoes in the garden last night, a familiar loud buzz zoomed by my ear. You may be hearing that same ferocious buzzing as you are picking the backyard tomatoes, figs, corn and berries these days. You just might be disturbing the eating habits of the green fruit beetle (Cotinis mutabilis), munching away at the overripe and damaged fruits and vegetables in your garden. It's not just the sound that will stop you in your tracks. The combination of the biplane-like buzz as well as the sight of these slow flying, large (an inch and a quarter long), metallic green-shelled creatures might make you drop your crops.

And yes, here in California, add the green fruit beetle to the list of suspects when you notice a chomped-on tomato.


Entomologist Baldo Villegas of the California Department of Food and Agriculture says his office has noted the growing presence of green fruit beetles in southern Sacramento County, beginning a few years ago. Until the 1990's, they had only migrated as far north as Fresno.

     "This beetle is now widespread from Mexico to the southwest and into northern California," says Villegas. "They are migrating northward fast." Villegas explains that the beetle is more vexing for backyard gardeners than commercial growers. "I consider them a nuisance pest," says Villegas. "They feed on rotting or open fruit and are attracted to them by the gas emitted by the fruit."


A native of Mexico, Villegas recalls the green fruit beetle as a harbinger of summer. "We used to catch them on fruit damaged by birds or in rotting fruit laying around on the ground," says Villegas. "We would tie a piece of string on one of their hind legs and that would allow them to fly along side of us."


Unlike a balloon on a string that escapes your grasp, the green fruit beetle is not going to drift away, high into the sky. Right now, those beetles are laying their eggs in your piles of garden compost, manure and mulch. So, the best control is to remove any such piles from the areas where you have seen the feeding adults. Turning the piles frequently will expose the larval stage of these beetles, a C-shaped, creamy white grub. Hand picking or flooding the area for two days can limit these noisy munchers during the next gardening season. And, chickens consider those grubs a delicacy.

To limit the spread of the adult beetles now, take away their food supply: fruit that is getting too soft on the vine. Trapping might be somewhat successful, according to UC Davis Integrated Pest Management Director Mary Louise Flint. In her book, "Pests of the Garden and Small Farm," she says that the green fruit beetle can be attracted to a half-filled one gallon jar, containing a 50-50 mix of peach or grape juice and water. Make a funnel out of small mesh wire and place it in the jar's opening. This will allow the beetles to get inside, but not back out. 

Insecticides are not recommended against the adult green fruit beetle. The UC Davis Integrated Pest Management website offers these tips for green fruit beetle control: "Early harvest and removal of fallen fruit can also reduce damage. To manage grubs (pictured here), remove all manure, lawn clippings, or leaf piles from areas near fruit trees and turn compost piles frequently to speed decomposition and expose small grubs. If grubs are found, they may be killed by flooding the infested area for at least 2 days."

And if the buzzing is too loud? Another good argument for I-Pod gardening.

Wednesday, July 21, 2010

A Great Year for Tomato Blossom End Rot

2010 is shaping up as a great year for backyard tomatoes...with blossom end rot. During tomato planting time here (late April-early May), the weather was cooler than normal, and much wetter. That pattern continued through the rest of May; our typical valley heat didn't arrive until late June. Tomatoes took their time. There are still gardeners waiting patiently for their beefsteaks and other main season tomatoes to turn red (true here, too).

For those tomatoes that are ripening, many gardeners are now contending with a major outbreak of blossom end rot. Tomato plants with blossom end rot show small, light brown spots at the blossom end of immature fruit. The affected area gradually expands into a sunken, leathery, brown or black lesion as the fruit ripens. Hard, brown areas may develop inside the fruit, either with or without external symptoms.

According to the tomato heads at UC Davis, the problem occurs when tomato plants have grown rapidly during the early part of the season and are then subjected to hot dry weather when the fruits are in an early stage of development. You know, sort of like the weather in late June.

Some tomato varieties are more susceptible to blossom end rot, including plum and pear-shaped tomatoes.

Although the weather and the variety of tomato sets the table for blossom end rot, many other factors are major contributors. 

Mainly, you. 

Yes, blossom end rot is related to a deficiency of calcium in the tomato fruit, but that occurs for several reasons that can be classified as “operator error”. Among them:

• Too much water.

• Not enough water.
• Irregular soil moisture, brought on by, um, irregular watering.
• Too much nitrogen fertilizer.
• Planting in soil whose pH is not conducive to calcium uptake by the plant (below 5.5 or above 8).
• Planting in poorly drained soil.
• Planting in too sandy of a soil.
• Improper planting (spreading out the roots when planting helps the plant adapt better)
• Excessive levels of potassium.
• Excessive pruning.
• Lack of an organic mulch. (organic mulch helps moderate soil temperature and moisture fluctuations)
• Using a plastic mulch which might raise the soil temperature too high.
• Planting certain tomato varieties that are prone to blossom end rot, especially narrow paste tomatoes.

The most critical mistake gardeners contribute to blossom end rot: not monitoring the soil moisture at root level.

Although the surface of the soil may appear dry, the moisture level a few inches down may be correct. If more water is added at that time, then the soil becomes so moist that oxygen is unavailable for root growth and calcium will not be absorbed. Why? Excess soil moisture, combined with a lack of soil oxygen, speeds the formation of Casparian strips, deposits on the young root tips that have become suberized, waxy substances through which water and nutrients cannot move.

If the soil in the root zone is too dry, then the calcium will not move to the roots. Dry soil and hot, dry, windy days create a water and calcium deficiency in the plant. Even a brief soil water deficit can disrupt water and nutrient flow in the plant. If this occurs while fruits are developing, blossom-end rot will likely develop.

Automatic irrigation timers may save you time, but it may not save your tomato plants from blossom end rot. Watering schedules need to be adjusted to the weather to maintain even soil moisture.

And when it comes to garden problems, many folks think the answer is, “buy something and put it on the plant”.  

Buying stuff won’t necessarily end blossom end rot.
Among the “store-bought remedies” that are frequently suggested that have been proven to be of little or no value to ending blossom end rot:

• Applying a foliar calcium spray to the tomato leaves. In University tests, studies showed that calcium does not move from leaves to the fruits. Thus, foliar sprays of calcium won't correct blossom end rot. Tomato fruits do not have openings in the epidermis (skin) through which calcium can be absorbed. Contrary to past belief, the direct application of calcium as a spray is ineffective.

• Adding a calcium supplement, such as gypsum, limestone, or eggshells. Perhaps. But it depends on your soil. 

• Limestone can raise the pH in soil to a range more favorable to tomatoes and calcium uptake, around 7.0. But if your soil is already in that range, adding limestone may raise the pH to the point where calcium uptake is again, slowed.

• Adding crushed eggshells to the soil well before transplanting time may help overcome any calcium deficiency already in the soil. But it ain’t gonna help your tomatoes if they are already in the ground.

• And gypsum (calcium sulfate)? Dr. Linda Chalker Scott of Washington State University's Horticulture Department, and author of the award winning book, “The Informed Gardener”, says home gardeners are wasting their money. “Most urban soils are not improved by adding gypsum,” she states in her on-line newsletter, “Horticultural Myths”. “Adding gypsum to sandy or non-salty soils is a waste of money, natural resources, and can have negative impacts on on plant, soil and ecosystem health.” However, she points out, gypsum can improve the structure and fertility of heavy clay soils; but consider another undesireable result to adding gypsum: Gypsum can have negative effects on mycorrhizal inoculation of roots.

Maintaining the proper balance of potassium, phosphorus and other soil nutrients and avoiding excessive growth due to over-fertilization with nitrogen is recommended. Several university studies, including a study from Cornell University and one from North Dakota State University, suggest that a low nitrogen, high phosphorus, low potassium fertilizer (such as a 4-12-4) may help control blossom end rot.

Excess levels of ammonium (NH4-N), magnesium, potassium and sodium have been reported to reduce the availability of calcium. A University of Nebraska  study reported that the use of nitrate nitrogen (NO3) stimulates Calcium uptake while ammonium nitrate (NH4) reduces the uptake of Calcium.

Their best advice: A soil test should be conducted to help determine what needs to be added and what should not be added to your garden soil.


And, use a moisture meter


Monday, July 19, 2010

Gardening Shoes, For Real




 I got a quick rise when I read the headline of the latest blog post from the UC Davis Good Life Garden: "Tennis Shoes? Flip Flops? Or Do You Garden in Rubber Boots Too?"

Finally, I thought, a discussion of functional garden footwear! But, sadly, no. That blog was a promotion for another blog, which uses the phrase, "Rubber Boots" as part of its title.

So, I guess it's time to weigh the pros and cons of the various styles of gardening shoes here.

Note that I said "gardening shoes", not "garden shoes". 
There is a difference. 

"Gardening shoes" imply footwear that combines function, comfort and safety while working outdoors. 

"Garden shoes" are an amalgam of style and color, with an overabundance of plastic. Their job: make the gardener look good, as in "Don't these purple sandals complement my English Lavender? And they go so well with the mauve wall color in our dining room!"

"Gardening shoes" are worn by horticultural heroes for whom the term "sweat shirt" means "cool weather warmth" or "The stinky, wet short-sleeve tee with the 1977 Lynyrd Skynyrd Tour Schedule on the back that gets worn every Saturday".

These are the gardeners who are dripping perspiration by 10 a.m., after spending the early morning shoveling, wheelbarrowing and transplanting.

"Garden shoes" are on the feet of rose snippers, leaf fondlers and blossom sniffers who wander through their garden after Sunday brunch, a copy of Sunset magazine in one hand, a Mimosa in the other. Their main job: straighten up the area so that their landscape service doesn't think they are slobs. Their shoes were not constructed to traverse any of these outdoor conditions: mud, weeds, snails or walking any distance more than the 70 feet between the front porch and the back fence. 

And that's assuming they have a "backyard". Sorry, but that patio/outdoor kitchen (complete with overhead fan and pizza oven) inlaid with the 400 square feet of travertine tile that supports six oversized terracotta planters from Pottery Barn doesn't count. This group can take a swiveling seat in their Martha Stewart Bistro table and chair set and go back to reading the artichoke quiche recipes in Sunset while us gardeners talk practical footwear.

What do hard working gardeners want in a shoe? A shoe that doesn't distract from a day in the yard. A shoe that a gardener can spend the entire day wearing without a complaint, racking up the miles and the fingernail dirt. A worry-free shoe that doesn't make you stop in mid-pruning to take care of blisters, cramped toes or sticky weeds that work their way into the socks. A shoe that repels water during a broken sprinkler repair job. A shoe with a solid sole for shoveling and a reinforced toe for when you drop your shovel. A shoe with a sole that has some grip on slippery surfaces but doesn't track excess mud into the house.

No single shoe meets all those requirements. Some, though, come close. A review, based on 30 years of yardwork. The grading system:
**** Great for gardening use. You won't think about them at all.
*** Recommended, with certain limitations. Good backup pair.
** Feels good when you put them on... you'll regret it later.
*  Great while sitting on the patio. Hey, is there something burning in your outdoor pizza oven?

Function: *** Does it all for Pacific Northwest gardeners.
Comfort: ** Fine, for about 15 minutes.
Safety: **** Ain't nothin' gonna attack you through that!

Function: **** Blundstones!
Comfort: **** Blundstones!
Safety: *** Blundstones! (But they will track in mud)

Function: *** Does it all; laces attract sticky weeds.
Comfort: *** With the right socks, yes.
Safety: *** Won't stop the mud in the house.

Function: *** Hard sole is good for digging.
Comfort: **** Wear 'em all day!
Safety: *** Clean before going inside, or your safety is at risk.

Function: ** Not for digging or making mudpies.
Comfort: *** Yes, until the insides are gravelly.
Safety: *** Watch your ankles for insect bites.

Function: *** A harder sole is better for digging.
Comfort: *** Excellent, until wet.
Safety: ** Foxtails stick in laces.

Function: * Have you ever tried digging in sandals?
Comfort: ** Fine, til the bottoms of your feet get sweaty.
Safety: * Choose nail polish to match stubbed toes.

Function: * Matches blooms of "Cherish" rose.
Comfort: ** While sitting, drinking Mimosas...sure!
Safety: * What's crawling on my toes? Eww, it's a bug!

Function: * Compacts soil. Twists ankles.
Comfort: * If you like the feel of nipple rings, you'll like these.
Safety: * Not for use during backyard games of "Twister".

Function: * Slug squishing keeps feet cool!
Comfort: ** Fine, until you step on a rock.
Safety: * At least your socks won't bunch up.

Sunday, July 18, 2010

Plants That Attract Beneficial Insects

Nature wants to make your job as a gardener as easy as possible; but you have to help. We've talked about putting in plants that attract insects whose primary job is to pollinate your garden, helping to insure a bountiful harvest of food and flowers. 

But what about attracting those other "good bugs", the crawling and flying creatures whose diet includes pests that are ravaging your garden plants? These beneficial predatory insects do not live on aphid steaks alone. They need other natural sources of food and shelter for their entire life cycle before they call your backyard a permanent home. 

What are these "Welcome Mat" plants and the beneficial insects they attract?

English Lavender

 Here is a list of those good bugs and the plants that they like to visit for shelter and as another source of food for their diet, the sugar from flowers. For some beneficials, especially syrphid flies, this nectar is necessary in order to mature their eggs. Intersperse these plants among the “problem pest areas” in your yard to attract the garden good guys.

LACEWINGS (Chrysopa spp.)
Beautiful, little (3/4”) green or brown insects with large lacy wings. 

Individual white eggs are found laid on the ends of inch-long stiff threads. 

It is the larvae (which look like little alligators) that destroy most of the pests. They are sometimes called aphid lions for their habit of dining on aphids. They also feed on mites, other small insects and insect eggs. On spring and summer evenings, lacewings can sometimes be seen clinging to porch lights, screens or windows.

Plants that attract lacewings:
•Achillea filipendulina    Fern-leaf yarrow
•Anethum graveolens    Dill
•Angelica gigas    Angelica
•Anthemis tinctoria    Golden marguerite
•Atriplex canescens    Four-wing saltbush
•Callirhoe involucrata    Purple poppy mallow
•Carum carvi    Caraway
•Coriandrum sativum    Coriander
•Cosmos bipinnatus    Cosmos white sensation
•Daucus carota    Queen Anne’s lace
•Foeniculum vulgare    Fennel
•Helianthus maximilianii    Prairie sunflower
•Tanacetum vulgare    Tansy
•Taraxacum officinale    Dandelion 

Easily recognized when they are adults by most gardeners. However, the young larvae, black with orange markings, eat more pests than the adults, and they can’t fly. Yellowish eggs are laid in clusters usually on the undersides of leaves.
Ladybug larva


Plants that attract ladybugs:
•Achillea filipendulina    Fern-leaf yarrow
•Achillea millefolium    Common yarrow
•Ajuga reptans    Carpet bugleweed
•Alyssum saxatilis    Basket of Gold
•Anethum graveolens    Dill
•Anthemis tinctoria    Golden marguerite
•Asclepias tuberosa    Butterfly weed
•Atriplex canescens    Four-wing saltbush
•Coriandrum sativum   Coriander
•Daucus carota    Queen Anne’s lace
•Eriogonum fasciculatum   CA  Buckwheat
•Foeniculum vulgare    Fennel
•Helianthus maximilianii    Prairie sunflower
•Penstemon strictus    Rocky Mt. penstemon
•Potentilla recta ‘warrenii’   Sulfur cinquefoil
•Potentilla villosa    Alpine cinquefoil
•Tagetes tenuifolia    Marigold “lemon gem”
•Tanacetum vulgare    Tansy
•Taraxacum officinale    Dandelion
•Veronica spicata    Spike speedwell
•Vicia villosa    Hairy vetch


Also known as syrphid fly, predatory aphid fly or flower fly. Adults look like little bees that hover over and dart quickly away. They don’t sting! They lay eggs (white, oval, laid singly or in groups on leaves) which hatch into green, yellow, brown, orange, or white half-inch maggots that look like caterpillars.
They raise up on their hind legs to catch and feed on aphids, mealybugs and others.

Plants that attract hoverflies:

Achillea filipendulina
•Achillea filipendulina    Fern-leaf yarrow
•Achillea millefolium    Common yarrow
•Ajuga reptans    Carpet bugleweed
•Allium tanguticum    Lavender globe lily
•Alyssum saxatilis    Basket of Gold
•Anethum graveolens    Dill
•Anthemis tinctoria    Golden marguerite
•Aster alpinus    Dwarf alpine aster
•Astrantia major    Masterwort
•Atriplex canescens    Four-wing saltbush
•Callirhoe involucrata    Purple poppy mallow
•Carum carvi    Caraway
•Chrysanthemum parthenium    Feverfew
•Coriandrum sativum    Coriander
•Cosmos bipinnatus    Cosmos white sensation
•Daucus carota    Queen Anne’s lace
•Eriogonum fasciculatum    CA Buckwheat
•Foeniculum vulgare    Fennel
•Lavandula angustifolia    English lavender
•Limnanthes douglasii    Poached egg plant
•Limonium latifolium    Statice
•Linaria vulgaris    Butter and eggs
•Lobelia erinus    Edging lobelia
•Lobularia maritima    Sweet alyssum white
•Melissa officinalis    Lemon balm
•Mentha pulegium    Pennyroyal
•Mentha spicata    Spearmint
•Monarda fistulosa    Wild bergamot
•Penstemon strictus    Rocky Mt. penstemon
•Petroselinum crispum    Parsley
•Potentilla recta ‘warrenii’   Sulfur cinquefoil
•Potentilla villosa    Alpine cinquefoil

•Rudbeckia fulgida    Gloriosa daisy
•Sedum kamtschaticum    Orange stonecrop
•Sedum spurium    Stonecrops

•Solidago virgaurea    Peter Pan goldenrod
•Stachys officinalis    Wood betony
•Tagetes tenuifolia    Marigold “lemon gem”
•Thymus serpylum coccineus    Crimson thyme
•Veronica spicata    Spike speedwell
•Zinnia elegans    Zinnia "liliput"


Parasites of a variety of insects. They do not sting! The stingers have been adapted to allow the females to lay their eggs in the bodies of insect pests. The eggs then hatch, and the young feed on the pests from the inside, killing them. After they have killed the pests, they leave hollow “mummies.”

Braconid wasps (pictured, left) feed on moth, beetle and fly larvae, moth eggs, various insect pupae and adults. If you see lots of white capsules on the backs of a caterpillar, these are the braconid cocoons. Leave the dying  caterpillar alone!

Ichneumonid wasps (pictured, left) control moth, butterfly, beetle and fly larvae and pupae. 

Trichogramma wasps (pictured, right) lay their eggs in the eggs of moths (hungry caterpillars-to-be), killing them and turning them black.

Plants that attract parasitic mini-wasps:
•Achillea filipendulina    Fern-leaf yarrow
•Achillea millefolium    Common yarrow
•Allium tanguticum    Lavender globe lily


•Anethum graveolens    Dill
•Anthemis tinctoria    Golden marguerite
•Astrantia major    Masterwort
•Callirhoe involucrata    Purple poppy mallow
•Carum carvi    Caraway
•Coriandrum sativum    Coriander

•Cosmos bipinnatus    Cosmos white sensation
•Daucus carota    Queen Anne’s lace
•Foeniculum vulgare   Fennel
•Limonium latifolium    Statice
•Linaria vulgaris    Butter and eggs
•Lobelia erinus    Edging lobelia
•Lobularia maritima    Sweet alyssum - white
•Melissa officinalis    Lemon balm
•Mentha pulegium    Pennyroyal
•Petroselinum crispum    Parsley
•Potentilla recta ‘warrenii’   Sulfur cinquefoil
•Potentilla villosa    Alpine cinquefoil
•Sedum kamtschaticum    Orange stonecrop

•Sweet alyssum - white
•Tagetes tenuifolia  Marigold - lemon gem
•Tanacetum vulgare    Tansy
•Thymus serpylum coccineus   Crimson thyme

•Zinnia elegans    Zinnia - 'liliput'


Parasites of caterpillars (corn earworm, imported cabbage worm, cabbage loopers, cutworms, armyworms), stink bugs, squash bug nymphs, beetle and fly larvae, some true
bugs, and beetles. Adults are 1/3 to 1/2 inch long. White eggs are deposited on foliage or on the body of the host. Larvae are internal parasites, feeding within the body of the
host, sucking its body fluids to the point that the pest dies.

Plants that attract tachinid flies:
•Anthemis tinctoria    Golden marguerite
•Eriogonum fasciculatum    CA Buckwheat
•Melissa officinalis    Lemon balm
•Mentha pulegium    Pennyroyal
•Petroselinum crispum   Parsley
•Phacelia tanacetifolia    Phacelia
•Tanacetum vulgare    Tansy
•Thymus serpyllum coccineus    Crimson thyme

Tiny (1/20 inch long) bugs that feed on almost any small insect or mite, including thrips, aphids, mites, scales, whiteflies and soft-bodied arthropods, but are particularly attracted to thrips in spring. 

DAMSEL BUGS (Nabis spp.)
Feed on aphids, leafhoppers, plant bugs, and small caterpillars. They are usually dull brown and resemble other plant bugs that are pests. Their heads are usually longer and narrower then most plant feeding species (the better to eat with!).


BIG EYED BUGS (Geocoris spp.)
Small (1/4 inch long), grayish-beige, oval shaped) bugs with large eyes that feed on many small insects (e.g., leaf hoppers, spider mites), insect eggs, and mites, as both nymphs and adults. Eggs are football shaped, whitish-gray with red spots.

Plants that attract minute pirate bugs, damsel bugs and big eyed bugs:
•Carum carvi    Caraway
•Cosmos bipinnatus    Cosmos “white sensation”
•Foeniculum vulgare    Fennel
•Medicago sativa    Alfalfa
•Mentha spicata    Spearmint
•Solidago virgaurea    Peter Pan goldenrod
•Tagetes tenuifolia   Marigold “lemon gem”

More Tips to Keep Beneficial Insects 
Working in Your Yard:

• Use a wide variety of attractive plants. Plants that flower at different times of the year can provide beneficials with nectar and pollen when they need it.

• Plantings that are at least 4' by 4' of each variety work best at attracting beneficials. 

• A bird bath or backyard water feature not only attracts birds (another predator of insects), but also attracts beneficials.

• Pesticides can kill the good guys, too. Avoid using broad spectrum insecticides (especially those that contain ingredients derived from pyrethroids and organophosphates). Safer alternatives include horticultural oils, insecticidal soaps and products designed solely for specific pests, such as Bt (Bacillus thuringiensis) a bacteriacide for tomato hornworms.

• Tolerate minor pest infestations. The beneficial insects will get the memo before you do. This will provide another food source for the beneficials and help keep them in your yard.

• More information about  beneficial predatory insects: "The Natural Enemies Handbook", from the University of California Division of Agriculture and Natural Resources.

Let the garden good guys do the job first!