- A butterfly harvests nectar from larkspur, which borders a summer vegetable garden to attract benefical pollinators.
Summertime, and the living is ... buggy. High heat and vulnerable, unhappy plants magnetize waves of annoying and harmful insects to your garden. But before you crack the whip with toxic chemicals and environmentally unfriendly pesticides, consider these organic alternatives recommended by Demetria Christo, co-owner (along with Travis Cleaver) of EcoUrban Sustainable Landscaping Design & Services.
What are some safe, household means of pest control?
I recommend insecticidal soaps — using Seventh Generation (brand) soap, lavender or mint. It's a really inexpensive and safe way to treat soft-bodied insects like aphids, thrips, white flies, scale, things like that. Because it's a soap, it disrupts the outer membrane of their skin and paralyzes them. What you have is something really safe, as opposed to using something like Dawn, or some other kind of household soap, which has a lot of additives.
If you have mammals that are pests — say you have a cat digging up your garden, or a squirrel — cayenne pepper works really well as a deterrent. If you sprinkle that on your garden and reapply after it rains, that's pretty effective. That, in addition to physical barriers, like chicken wire if something's digging, so your plants can grow through the chicken wire.
There's also sesame oil, which can be expensive, but it's used as a primary ingredient in Organocide (an organic insecticidal spray). The oils suffocate soft-bodied insects and dissolve the egg casings.
What should someone look for when shopping for insecticide or pesticide?
They should make sure (the product) is not petrochemical-based. It should be made from natural ingredients — look for something that says "can eat produce up to day of harvest." Usually that's a little tagline they put on there. Something made from fish emulsion and sesame oil can be sprayed on (a plant) and in the same day, give it a rinse and eat it and it's not going to hurt you.
What are some beneficial insects?
Wasps parasitize a lot of the little things eating your garden. There's a way to attract them with companion (plant) species. Anise attracts wasps and repels cabbageworm. [A wasp] is an example of a typical insect you would think is a problem pest but is actually beneficial because it's consuming the bad guys, and you can attract it with companion plantings.
It might also be helpful to have natural predators — lacewings, spiders, assassin bugs and, of course, pollinators. You want to make sure they have a source of water and a little habitat for them to reside in. Leave some leaves or a little bit of growth for them to hide in, otherwise they won't come.
What companion plants do you recommend?
Companion species are doing one of two things: They're attracting beneficial insects or repelling the bad guys. Things that attract beneficial [insects] include really nectar-rich plants — usually that means little, small flowers. That includes members of the carrot family, like dill, caraway, fennel. They attract aphid predators. Also, members of the mint family, like sage. Those natural aromatic compounds repel the bad guys. And then anything with a large landing pad from the daisy family, like sunflower, daisies, yarrow. Also, there are pollinators — they attract butterflies.
Any other techniques?
There are four things I would strongly encourage: First, observe your garden. Have an eye on what's going on in your garden and observe what's eating your leaves and what's not, what's killing the bad guys. Second, know what's a pest insect versus a beneficial insect and know what's a disease versus a pest. You can do that by having resources at hand. Thirdly, know your resources — there's the LSU AgCenter Plant Disease Diagnostic Clinic, and I recommend the Rodale's series on organic gardening and pest identification — fantastic books that are really easy to understand. And then, mulch, mulch, mulch. Mulching is really important. It prevents disease from splashing up on to your plants. It serves as a physical barrier from bugs getting on to your plants, holds moisture in the soil — it's really one of the bottom lines of gardening. For an edible garden, the most sustainable and easy mulch to use is crushed pine-needle mulch. Not pine bark, but pine needle. It's a little more expensive. Alternatively, you can use the noncrushed (pine needle mulch), and the pine bales are really inexpensive. An advantage there is that it's a natural, locally found material, and no trees are cut down in the process. They don't break down or attract termites, and it looks great and smells good. They're also acidic, which actually balances the basic pH of our soil here. It's a good, all-around sustainable mulch.
Also, cultural control. It's a matter of how you interact with your garden. You can start your plantings earlier if you know when the pests are expected; you can jumpstart the plantings before they get there. And if you start your plants from seedlings, they're less likely to be diseased and they can make it through that process. It's timing — just knowing when [pests] are coming out, and you can work around that naturally just by planning.
Call 274-8774 or visit www.ecourbanllc.com for more sustainable landscaping information.