Wednesday, July 17, 2013
What's Bugging You in July?
This is what our Natureworks customers are asking about this week...
Slugs- If you see holes and chew marks on your plants but never see a bug eating them, it's very likely that you have slugs. These are basically snails without shells. Yuck! They only feed at night or on very rainy, cloudy mornings. They hide in mulch, leaves, or other garden debris during the day. You can go out at night with a flashlight and see them hard at work. They can climb up really high on a plant. Don't be fooled! We use all natural Sluggo (iron phosphate) sprinkled around the base of the plants every three weeks. Before sprinkling Sluggo I pull aside the mulch and clean up a wide circle of any debris, leaving the soil exposed. Some people like to trap slugs using a shallow cat food can sunk into the ground filled with stale beer. Yeast and water will also do the trick. You then empty it every morning and refill it every night. For me, that's way too much work. But it will catch a lot of slugs!
Earwigs- These destructive pests also feed at night. They are long and skinny and have pinchers at the top of their heads. They climb way up into your butterfly bushes, Joe Pye weed (Eupatorium), and other summer flowers and devour the leaves. Sluggo Plus is the solution. This is iron phosphate with the addition of Spinosad which will kill the earwigs when they return to ground level. To trap them, place a cardboard paper towel tube at the base of your plants in the evening. The earwigs will hide in the tube and you can pour them into a bucket of soapy water in the morning.
Holly scale- All week long people have been bringing in "specimen bags" of holly that is covered with a black sooty mold. The mold is a symptom of an insect called holly scale (cottony camellia scale to be exact). This looks like a cottony white, linear mass which lives on the undersides of the holly leaves. It exudes a sweet, sticky sap. The black mold, which is what most people see first, grows on the sweet sap. Right now, the white casings that you see are actually empty as the eggs have hatched. Eventually the little crawling insects will lose their legs and be permanently attached to the vascular system of the leaves until next year. AFTER the heat wave you can spray with Neem or a low viscosity summer horticultural oil, making sure to spray the undersides of the leaves. In late March, spray your holly plants with dormant oil. I spoke at length with an entomologist at the CT Agricultural Experiment Station. They are a wealth of information. If you have specific questions you can call them at 203-974-8600.
Black spot- The roses are really starting to show signs of stress due to the excessive rain and humidity. Black spot is a fungus that turns the leaves black and then they fall off. My crews have been preventively spraying Oxidate and Actinovate to head this fungus off at the pass. If you have black spot already, open prune your roses (I will be demonstrating this at the garden walk this Saturday) to increase air circulation to the middle of the plant and remove ALL diseased leaves from the ground below. Garden santitation is critical. Then, spray the plants with liquid copper to kill the fungus spores. Do this ONLY in the early morning when it is cool. A few days later, foliar spray the roses with liquid seaweed (sold as Stress X, a powder that you mix with water) or Organic Plant Magic which is compost tea. Both will help your roses fight off the fungus and grow strong and refoliate again. In mid July I feed all of the roses a second time using Pro Start and compost. This routine really works and the roses burst back into bloom quite quickly and continue flowering into the fall!
Japanese beetles- I am on the warpath! Many mornings a week I go out to the garden with a plastic jug filled with soapy water and a tablespoon of canola oil and sneak up on the Japanese beetles that are feeding on my plants. Monday morning, after another round of this chore, I mixed up a batch of Neem and sprayed many of the plants to further control this destructive pest. I know which plants they are on: raspberries, roses, evening primrose, weeping cherry, and Persicaria. I didn't spray the raspberries as they are in full fruit and I didn't want to spray the berries. I sprayed everything else. Neem kills an insect when they ingest it so using it on the leaves of the affected plants provides a bit of longer term protection until I can make my early morning beetle runs again.
Hibiscus sawfly- I noticed the telltale damage from this little green worm-like creature about 3 weeks ago and sprayed with Neem. I checked my plants every few days and they have been clean...up until this weekend. Another round of Hibiscus sawflies hatched recently. I used the same Neem spray on my perennial hibiscus plants, making sure I sprayed the underside of the leaves. That should protect my plants until they start to bloom which will be in August.
Before we suggest an organic remedy for any pest problem we always ask a lot of questions to be able to identify the pest correctly. We NEVER tell people to blanket spray their gardens "just in case". Because the good bugs that eat or parasitize the bad bugs are hard at work in an organic ecosystem, it is critical to know your enemy and target it accurately.