With Summer come pest problems. Eggs hatch and spores germinate, and plants are food for all of us folks that don’t photosynthesize. So, what can we do? Share and defend, intelligently.
We have been taught to respond to these pest problems with a war-like attitude: point and shoot, poison and kill. At Harlequin’s we do resort to killing when necessary and we do provide non-toxic products that will kill pests, but first, let’s look at a bigger picture.
Harlequin’s Gardens has not used toxic chemical pesticides, fungicides and herbicides in its 32 year history and we have grown and supplied hundreds of thousands of plants to satisfied customers. So non-toxic pest management is possible. However, this nature-respecting approach requires both a more educated approach and a more tolerant attitude.
The Bigger Picture:
Most insects, fungi, bacteria and viruses are beneficial.
Strong, healthy plants have few pest problems.
A diverse plant community supports Nature’s own defense systems. Include plants in your garden from many different plant families, with flowers of different sizes, forms and bloom-times.
Good nutrition provides plants with the energy they need to make their own chemical defenses.
Here are a few suggestions
To avoid pest problems:
Don’t over-fertilize, especially not with chemical fertilizers. Don’t over-water because when the soil is saturated with water, it drives out the oxygen; moist is good; soggy is bad. Fast growth is soft; it does not make healthy plants. Fertilize with organic, slow acting fertilizers and minerals (micronutrients) which strengthen a plant’s immune system. Water-soluble chemical fertilizers are quick to wash downstream, and need frequent applications. Organic fertilizers feed slowly over a long period of time.
To respond to insect problems:
If damages are less than 10%, WAIT; don’t shoot. If you leave some pests, they will provide food for the beneficial predatory insects who will lay eggs in your garden to become a stronger defense-force for next year. Pest management is best when Nature does it for us.
If damages are more than 10-20% or are happening rapidly, act with non-toxic products.
Controlling aphids: A strong spray of water is effective for dislodging aphids and other soft-bodies insects. Neem and garlic sprays can repel pests and stop them from feeding. If the problem lasts more than one season, check the cultural conditions: does the plant need more or less sunlight, air circulation, water, mulch, or nutrition? Or maybe it’s the wrong plant for the location.
Foliar sprays of liquid kelp and compost tea will strengthen and toughen leaf surfaces, thereby reducing puncturing by sucking insects and fungal pathogens. Anti-transpirant sprays like Wiltpruf can prevent fungal problems and preventative sprays of Neem can also prevent diseases. A fine woodchip mulch prevents disease spores from splashing onto leaves. PREVENTION is the most successful approach to diseases.
To kill pests without poisons:
To control soft-bodied insects like aphids, spider mites and caterpillars try using:
1) Horticultural Oil – a non-toxic petroleum oil that suffocates the insect. Must make direct contact with the pest to be effective.
2) Insecticidal Soap kills by desiccation, and must make direct contact with the pest to be effective.
3) Neem will kill pests if sprayed directly on the insect, and if a pest eats the leaf with neem, it can prevent the insect from molting (moving to its next stage). Make sure the neem product contains azadiractin as an ingredient, and mix with warm water and a few drops of mild dish soap.
4) Diatomaceous Earth is ground-up diatoms, very sharp to an insect’s hard shell or soft body. The insect can die of dehydration. Not poisonous to mammals but should not be inhaled, so wear a dust mask.
5) Garlic concentrate can kill aphids, earwigs, spider mites etc. It can also repel insects, even grasshoppers (ask for Harlequin’s new formula-a trial)
6) Systemica is a new pest control product for us from Sierra Natural Science. It is OMRI certified, safe for bees and birds, made from Rosemary and Clove oils with Soapbark and Humic Acid, and comes in a hose-end sprayer. It is said to be systemic when sprayed on leaves and on soil and absorbed into the plant sap, supposedly like a plant’s own chemical mechanism. At this time we have little personal experience. We don’t know whether it affects the flavor or nutrition of food crops. Let us know your experience.
7) We also have Sierra Natural Science Disease & Fungal Control, their Miticide, and their Insecticide made with peppermint, soap and other OMRI organic ingredients, and a product called Disease and Fungal Control that is supposed to be better than our old-faithful Green Cure which was made unavailable when the company was sold. All are made with OMRI certified organic ingredients.
8) BT- Dipel: a bacteria used in organic production which kills caterpillars like cabbage worms, that eat the leaves of our veggies.
Non-toxic sprays are not as strong as toxic chemicals, and therefore will often need to be repeated. If damage is bad, repeat in 3 days. If not so bad, spray weekly for 3 weeks. Most pests are gone in 3-4 weeks. When pests eat the leaves, it stimulates the plants’ defense chemicals, making the plants stronger.
Specific current pests:
Rose Slug or sawfly: Makes holes and trails in rose leaves, can happen rapidly. Look mostly under the leaf for a light green “worm” both tiny and large. All the above products should work (except Dipel) To spray the undersides of the leaves, you may need to get a special sprayer-we sell a very good cheap hand sprayer you can spray upside down.
Flea Beetle: This one is hard to control. The product we used to sell is off the market. Now we suggest spraying with neem (must contain azadiractin) or Sierra PC and immediately dust with Diatomaceous Earth. Do this three days in a row. Our strong garlic concentrate might help.
Sluggo – in store now
Slugs and Snails love cool and wet conditions. We carry non-toxic Sluggo, a granular bait to sprinkle around on the ground that contains the naturally occurring active ingredient iron sulfate, which is highly effective in controlling snails and slugs by causing them to stop feeding. It is safe around pets and wildlife. CSU has more information on slugs here.
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“The Book” on non-toxic pest management has not been written. It is a complex subject, and the availability of specific effective non-toxic products keeps changing. We hope to see big improvements in the future because of a growing market of folks who want to save our insects and our own health. Vote with your dollars.
Please remember: The overwhelming majority of insects and fungi are our friends and allies, and many are essential to the survival of other species. It is best to avoid pest problems by providing individual plants with the nutrition they need to defend themselves and to provide plant diversity for a holistic environmental balance. Our best relationship with Nature is as a Partner, not as an adversary. But if you have to act, don’t use a poison. Toxic Pesticides don’t know when to stop killing!