By planting several varieties of “attractor plants” you can invite the good guys in to fend off the bad ones without using harmful, toxic chemicals; certainly not something you want near the food you and your family are going to eat.
Lady Bird Beetles (ladybugs) are good friends to have around if aphids are a problem in your garden. They can eat about 50 aphids per day. They are very attracted to alyssum “Goldkugel” and “White Night”, yarrow, ajuga, marigold “Lemon Gem”, fennel, and sunflowers.
But your new best friend might be the lesser-known lacewing (the aphid lion). It may be so small you don't even see it, but it eats 20 times more aphids each day than a ladybug. You are almost certain to attract them by planting yarrow, dill, cosmos, coriander, Queen Anne's lace, and flowering mustard.
Bees are essential when growing edibles. More than 30 percent of all the food we eat is pollinated by bees. I am happy to report that I have the beautiful buzz of bees in my backyard year-round. To keep them happy I have planted a dozen varieties of salvia. Not only are they beautiful, they are easy to grow, come in all sizes and colors and take very little water once established. What's not to love? And, although most prefer full sun, there are many options that thrive in part sun to fairly deep shade.
Another favorite that both my bees and I love is lavender. It comes in all shades of purple (from very dark to pale purplish-pink) and even white. So why settle for just one? Don't have a lot of space? Choose one of the several dwarf options.
Rosemary is not only hardy, drought-tolerant, fragrant, and great for cooking, it attracts bees even in our wet winter months. For other flowering plants that are attractive as well as attracting try black-eyed Susan, calendula, purple coneflower, butterfly bush, bee balm, and sedums.
Hoverflies, also known as syrphid flies, look like small bees but literally hover over a plant or flower and then quickly dart away. By watching their movement you can easily distinguish them from bees. They do not sting, and they eat aphids, mealybugs, and thrips. They also like yarrow, alyssum, dill, garlic chives, and fennel. But try adding dwarf alpine aster, feverfew, statice, lemon balm and parsley to keep them healthy and happy.
There are many varieties of parasitic wasps. Again, at first glance they may look like a bee, but, if you look closer you will see that they have few if any, hairs. Bees are pollen collectors so are generally quite hairy. Wasps feed on tomato hornworms, cabbage worms, beetles, stink bugs, squash bugs, fly larvae and more. These little guys are great in the garden, and again they do not sting. Plant buckwheat, lemon balm, creeping thyme, cosmos “White Sensation”, lobelia, zinnia “Liliput”, parsley and Linaria.
Your garden is its own ecosystem. It takes time to build a healthy, thriving, environment that can mostly take care of itself. So, be patient, strive for diversity and trust me, if you plant it … they will come.
by UC Master Gardener Rebecca Jepsen
This article first appeared in the May 27, 2018 print issue of the San Jose Mercury News.
Beneficial insects are those that improve pollination, gobble up or lay their eggs inside insect pests, or speed up decomposition. Common beneficial insects include honeybees, minute pirate bugs, syrphid flies, assassin bugs, tachnid flies, big-eyed bugs, lacewings, native bees, parasitic wasps, butterflies and damsel bugs. Lady beetles are one of the most popular beneficial insects. A single lady beetle may eat 50 aphids a day, but it will fly away if its needs are not being met.
You can make your Morgan Hill yard and garden more welcoming to beneficial insects by meeting those needs with year round food, water, and shelter, using native plants. Local insects have evolved using native plants for food and shelter for thousands of years. Hedgerows and clusters of native shrubs and perennials can provide low-maintenance habitat for many beneficial insects.
To attract pollinators, try adding these plants to your landscape:
- Brandegee Sage (Salvia brandegeei)
- Borage (Borago officinalis – not native, but highly effective)
- California poppies (Eschscholzia californica)
- Coast buckwheat (Eriogonum latifolium)
- Great Valley gumweed (Grindelia camporum)
- Tansy (Phacelia tanacetifolia)
- Wild Liliac (Ceanothus sp.)
The following native plants make excellent habitats for pest-eating insects (with buckwheat being the favorite of most beneficial insects):
- Blue wildrye (Elymus glaucus)
- California buckwheat (Eriogonum fasciculatum foliolosum)
- California coffeeberry (Rhamnus californica tomentella)
- California lilac (Ceanothus griseus)
- California onion grass (Melica californica)
- Coyote brush (Baccharis pilularis)
- Creeping wildrye (Leymus triticoides)
- Elderberry (Sambucus mexicana)
- Manzanita (Arctostaphylos sp.)
- Nodding needlegrass (N. cernua)
- One-sided bluegrass (Poa secunda)
- Purple needlegrass (Nassella pulchra)
- Toyon (Heteromeles arbutifolia)
Providing shelter for beneficial insects often means nothing more than providing a source of water and avoiding the use of broad-spectrum pesticides and bug zappers. Pesticides and bug zappers often kill beneficial insects. According to research published in science research journal PLOS One, insect hotels may or may not be effective, but they might help and they do make nice garden art. Since each insect species has its own habitat needs, creating different levels within a landscape, using trees, shrubs, perennial beds, and low-growing ground cover can provide the widest variety of shelter possibilities. Shelter can also take the form of bare patches of soil or sand for ground dwelling solitary bees.
Plant a variety of colors and shapes, making sure that food and habitat are available year-round whenever possible. Some beneficial insects love round chive blooms, while others prefer the flat landing area provided by cilantro. Salvia's spikey blooms and daisy-like sunflowers fill out the range of flower shapes. Many delicious herbs, such as rosemary, oregano, dill, and thyme are irresistible to beneficial insects.
The rainy days of November are an excellent time to draw or list existing plants, noting when they bloom, their color and blossom shape, and which beneficial insects they attract. The next step is to see what is still needed for the biggest impact. If your Morgan Hill garden has specific pests that attack regularly, you can install plants to attract beneficial insects known to feed on those pests.
For more information, visit Master Gardeners or call 408-282-3105, Monday through Friday, 9:30 a.m. to 12:30 p.m.
by UC Master Gardener Kate Russell
This article first appeared in the November 9 issue of the Morgan Hill Life.
The benefits of Bugs
Don't squash those insects -- some may be good for your garden
by Crystal Tai / Palo Alto Weekly
While "benefits" and "bugs" seem like antonyms, certain insects actually help organic gardens be healthier.
The key is not to be too liberal with bug sprays, she said. "It is important to avoid broad-spectrum pesticides, even so-called 'organic' or plant-based insecticides, as they will kill beneficial insects as well as pests," she said.
Instead, Simpson, who teaches a class on bug benefits to gardens, suggests that home gardeners should manage pests through things like physical barriers and traps, hand removal, and encouraging natural enemies to prey upon plant parasites.
When pests do multiply too quickly to be brought under control by natural enemies, Simpson suggests choosing pesticides that have the least negative effect on the environment or any organism other than the one to be controlled. Good options include dormant oils, which might be used to smother insect eggs on dormant fruit trees, and insecticidal soaps, which might be used on a very bad aphid infestation.
Also, a bacterial pesticide called Bacillus thuringiensis, or "Bt" for short, can be used to destroy cabbage worms, according to Simpson. She said Bt wouldn't affect bees or other beneficial insects, though it can kill caterpillars.
"Fortunately, many butterflies lay their eggs on plants that are not for food," said Simpson. "So if you just apply Bt carefully to food plants that are being eaten by caterpillars, only those caterpillars will be affected. Or a good alternative is to handpick caterpillars that are eating your veggies and skip the Bt. That is what I do."
Caterpillars are not the only insects that blur the line between beneficial bugs and pests, Simpson said.
"All insects have a role to play in the ecosystem. Flies and mosquitoes can pollinate flowers, and ants eat insect eggs and also aerate the soil. Pest insects and snails, which are not insects but mollusks, and their eggs are food for other organisms," she said.
Although mosquitoes may contribute to pollination, Simpson recognizes the annoyance and danger of their bites and the reasons for eliminating them. She only advises against using a pesticide that will kill other insects as well.
"Mosquitoes can be prevented from breeding by making sure there are no containers of standing water where they can lay eggs," said Simpson. "Or by using 'mosquito dunks,' small solid cakes of a bacterial pesticide that you float in water. They only kill mosquito and fly larvae. Or we can smash them. Or wear protective clothing or use insect repellent."
Palo Alto resident Sue Luttner also likes the "smashing" approach in some cases. She said she keeps an eye on all the leaves in her garden, and as as soon as she sees holes, she checks out the backs for eggs and larvae of pest insects, and then she smashes them.
"I like to spend time in the garden, and that gives me a chance to intervene early," said Luttner. "Most of the native plants don't seem especially susceptible to insect damage, but the vegetables and the fruit trees are, so I try to stay alert to bad bugs and kill them whenever I see them."
Gardeners can also discourage exploding insect populations by intermixing different crops -- placing tomato plants in ones or twos around the garden, for example, with beans or onions or something in between, so that if one patch gets infected, the bugs won't necessarily march unimpeded right through the entire crop, Luttner said.
"I've learned not to crowd the crops, because that invites aphids. When I do see signs of aphids, I either cut off the affected shoots or pull out the plant immediately," she said.
When it comes to aphids, Palo Alto Master Gardener Callie Elliston said she would wait for ladybugs to eat them. "Ladybugs can eat 30 to 50 aphids in an hour," said Elliston. "Some of my rose buds are covered with black and green aphids. I used to hose them off with water, but now I know that if I'm patient, the ladybugs will soon come to the garden and eat all of the invaders."
Ladybugs and their larvae help control aphids as well as other pests such as beetle larvae, white flies and mealybugs, said Elliston. She said ladybugs often lay eggs on the underside of leaves and gravitate to certain plants, such as cilantro, oregano, dill and yarrow. Some local hardware stores carry live ladybugs for purchase, something that can delight child gardeners.
Another idea is to get a good look at bugs with a magnifying glass. "An inexpensive 10X hand lens is a good investment for a gardener, to get a better look at insects and their activities," Simpson said.
Even with magnification, some beneficial bugs may be hard to distinguish from pests, Simpson said, adding that she can help people learn what to look for in terms of insects during her upcoming seminar on beneficial insects on April 21, 7-8:30 p.m. at Rinconada Library, 1213 Newell Road in Palo Alto.
This article first appeared in the Palo Alto Online website, Friday, April 15, 2016. Reposted with permission./h1>