Thanks to everyone who came to the Pest Control/Companion planting class last week! I had a great time and am looking forward to our next class on August 15 about Year Round Gardening. We’re planning other organic gardening classes including a workshop on making mason bee houses and insect homes, gardening for phytonutrients and more. Email sustainable@OverlookNeighborhood.org to sign up for the mailing list and be sure to hear when a class is coming up.
In our class last week I didn’t have time (No wonder! Look how long it is!) to go through my list of some of the tools organic gardeners can use to deal with a pest problem that occurs even after all the preventive measures we discussed. So here it is:
Tolerance. What would happen if you don’t intervene? For instance, if slugs were eating every single one of my strawberries I would take action. But if there were a few aphids on my calendulas, I would ignore it and let the parasitic wasps have their way with them. Ditto with weeds in the lawn – a huge spreading weed that will create a bare spot (for another weed to grow) will get pulled out, while clover, veronica and other little flowers are most welcome.
Picking. Hand picking is probably my most used tool against pests. Pick off diseased leaves when you see fungi like rust, black spot or shot hole starting. Squish sawfly larvae or aphids. Scrape off scale. It’s meditative and when you slow down in the garden you notice all sorts of things. Hand weeding is the best way to deal with almost all weeds. There are great tools nowadays that make it easy, ergonomic and fun like dandelion wrenches and hori-horis.
Hose sprayer. A strong blast from the hose can dislodge aphids. If aphids are a repeated problem for a plant, try to figure out what the underlying stress is: perhaps it’s not in the right location or it has been over-fertilized? Or ask your self if you should start thinking of it as a trap crop.
Compost tea. Spray on the foliage or pour on the roots of your plants to add nutrients and counteract fungal problems. Brew your own, trade with a friend or find one of the independent garden centers that has a brewing set up.
Rubbing alcohol (Isopropyl) can be used to wipe down plants that are badly infested with scale, mites or other small insects or sooty fungus. Great for house plants.
Nets and Scare tactics like fake owls, whirlygigs, sparkly streamers can deter birds that are competing for your berries or cherries.
Pantyhose or bags can be put over fruits like apples and pears while they are still small to protect them from insect damage.
Eco-lawn is a diverse planting that can be mown like regular turf grass but it requires less water, no fertilizer or chemicals, stays greener in summer, provides better habitat and helps rainwater infiltrate the soil better because it has deeper roots. It is started by seed and typically includes fine fescue grasses, clovers, English daisies, violets and other short, steppable flowers. You can overseed an existing lawn with clover or eco-lawn seed mix to start an eco-lawn. I include it here as an organic gardening ‘tool’ because it eliminates the biggest reason homeowners use chemicals – a ‘perfect’ lawn.
Tea kettle. A pot of boiling water poured over a gravel path, pavers or the cracks in the sidewalk kills weeds and their seeds. Use caution with boiling water obviously. The downside is the energy needed to boil water but it’s good for small areas and can be a reuse of water heated for another purpose, for instance pasta water.
Vinegar can be used the same way – pour white vinegar over weeds where you don’t plan to grow plants in the future. This is important as vinegar or boiling water kill beneficial soil micro-organisms and vinegar acidifies the soil making it inhospitable. Great for paths, patios, etc. Works best in hot, sunny weather. Downside is that most vinegar is made from grain which takes a lot of fossil fuels to grow in our current agricultural system and it may be GM which uses massive amounts of herbicide which is what we’re trying to avoid here.
Badminton racket. ‘Intervene in the most efficient point in the cycle’, says permaculture. Okay, so instead of picking off hundreds of cabbage moth caterpillars or squishing thousands of little eggs (gross exaggeration,) I will practice my backhand and take out a few cabbage butterflies. (Luckily I don’t have to do this anymore because 1. the butterflies like to go into my green house and die and 2. the wasps have my back and are eating the eggs and caterpillars. I always felt like it was bad karma killing butterflies, even a non-native ‘pest’.)
Traps made from card board tubes, rolled up damp newspaper or an old board catch slugs and earwigs. Check them in the morning and put critters into a pail of water with a drop of soap in it.
Beer. Some folks have great luck putting out saucers of cheap beer for the slugs who drown in it.
Sluggo is a commercial slug bait that is supposed to be non-toxic to kids and pets. One version, Sluggo-Plus also targets earwigs and other critters. The active ingredient is iron phosphate and it is allowed (per USDA standards) for use in organic gardening if other preventive measures are taken first.
Baking soda can be used as a preventive measure against black spot and other funguses when mixed with a spreader-sticker such as soap. There are lots of homemade recipes online. Try it on a small area of the plant first to make sure it tolerates it.
Diatomaceous earth is make of tiny, ground-up sea critter skeletons. The powder is dusted on and around plants and cuts the exoskeleton of insects that encounter it, causing death. Use for flea beetles, etc. It is non-toxic but should NOT be inhaled.
Boric acid mixed with honey kills ant colonies, if ants are really a problem (see first item, ‘Tolerance’. I draw the line when ants are indoors.) Be sure to put the bait in a location inaccessible by kids and pets. Do not inhale.
Goats can be rented to clear weeds from large areas including steep hills and places invaded by Himalayan blackberry or other noxious weeds.
Winter spraying with horticultural oil can help get ahead of disease on fruit trees.
Transplanting spade. Maybe a plant with a lot of troubles is just trying to tell you it is in the wrong place. Being moved to a sunnier/shadier/wetter/drier location (or your friend across town’s yard) might solve the problem.
Compost heap. When a plant is really a pain in the ass, ask yourself if it is worth the trouble.
There are so many more I haven’t mentioned here. What is your favorite organic pest control trick?