Of Predators and Prey

Mandeville has been working on poison free gardens for eight years. Many gardens are controlled without pesticides at all, and where we do use something, it is the plant-derived pyrethrons. We use soap and plant-derived neem oil to control mildew, aphid etc. We use beneficial bugs, lady bugs, lacewings, cucumeris (thrip eaters), spider mite eaters, wooley aphids destroyers to eat pest insects. We strip leaves to allow new leaves to come in clean. We use ferrous phosphate for slugs, harmless to humans and pets. Though we don’t reach perfection, the plants in our gardens look as good as when we used to spray, and the earth is a whole lot safer for pets, our wild life and us. I regularly compare our results with gardens treated under other regimes and we are doing well. I am proud to see how often I am greeted by a ladybug.when I come into the gardens

However we have become aware that the pest control companies are trying to sell spider and ant control around buildings, by either spraying, or putting powder in/on the soil. I would like to request that you don’t do this. What you do inside the house is neither here nor there, but outside we need an environment in balance.

In defense of spiders: I know that spiders have had a bad rap. The movie industry is not helping by portraying them as the incarnation of evil. However spiders are voracious predators. They eat many of the pests in the gardens as well as house and fruit flies. They are larger and can tackle bigger and more pests than most predator insects that we introduce. Please don’t try to eradicate them. If webs bother you, we will knock them down for you, but spiders are truly your friends in the garden.

As with DDT in condors and kestrels, low levels of poisons in the pests can build up in the predators, eventually killing them. They, like the condors, breed more slowly than their prey. The pests often breed every 3 to 4 days. After a plant is “cleared” of most insects by poisons, a few will remain. These breed fast and become a resistant population. The effect is that in a couple of weeks, we have a bounce back of the pests, with no predators working on our side. What we want is what I have in my garden, the aphids appear in the spring, and disappear as the predators get to work over a period of about 3 weeks.

Just imagine what it is like for my gardeners to put their hands in the soil and disturb a great glob of poisonous powder that they did not realize was there. If you must continue to use these services, please tell me, together with what kind of a schedule you are on. Try to schedule spraying after we have been there. At least give us a chance to protect ourselves. Sarah@mandevillegarden.com is the best way to let me know. I am currently researching and will hope to offer non-poisonous ant control, as ants make it difficult for us to control other pests. They farm aphid and scale, and keep the lady bugs off their herds, just as a shepherd keeps the wolves from the flock….. ain’t nature fascinating

Happy Gardening! - Sarah FitzGerald

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Front Garden in San Francisco with pleached carob trees
terraced garden in Sea Cliff on a foggy morning
Pacific Heights rose garden in August
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Copyright 2002-5 Mandeville Garden Company
716 Hacienda Way, Millbrae, CA 94030
(415) 626-6243, sarah@mandevillegarden.com
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