2015-06-17 / Gardening Tips / Columns

Gardening Tips: June 17, 2015

Garden Pests and Rain
By Bob Beyfuss

Since Memorial Day weekend I have recorded about 3.75 inches of rain at my house, which is enough to relieve the drought conditions we had experienced since April. Much of the region has had enough downpours and thunderstorms to allow gardens to finally take off. I hope you have rigged up a rain barrel or two to capture some of the runoff from the brief, but intense, storms that are typical in early June. A 55-gallon drum that is fed by a 30-foot gutter and downspout will fill up after only about an inch of rain providing irrigation water, should we go dry again. I use Mosquito Dunks to kill the mosquito larvae (wigglers) that will hatch after only a few days up to a week in standing water such as the rain barrels. This product is made from a naturally occurring bacteria (Bacillus thuringiensis often abbreviated as Bt) that only kills the larvae of mosquitoes and black flies and is considered non-toxic to most other organisms.

A number of readers have reported lots of leaf eating caterpillars in the region. There appears to be at least three different types of caterpillars responsible, including gypsy moths. Most gypsy moth outbreaks are cyclical and generally only last for two or three seasons. Others are a one-time event. Products using yet another form of the same bacteria (Bt) that kills the mosquitoes, are also effective against caterpillars that turn into moths or butterflies. Not all caterpillars are moth larvae but these products are effective against some of our most common vegetable garden pests, including cabbage worms. It is important to make a positive identification of whatever pest you are trying to get rid of before applying any pesticide. Local offices of Cornell Cooperative Extension can usually help in the identification process if you provide them with good samples of the pest. Collect at least 10 or more insect specimens, as well as samples of some of the specific plants that are being attacked.

Late night diners

Sometimes it is not so easy to discover the offending critter when the damage occurs at night. Cutworms will cut down transplants at soil level in the evening, leaving the cut off top of the plant lying on the ground and then hide buried in the soil during daylight hours. The easiest way to protect your expensive transplants is to loosely wrap the lower stems with aluminum foil as a physical barrier to the cutworms. Remove the foil when the stems area half inch thick or more. The other major nocturnal feeders are slugs. Slugs have not been too much of a problem this spring due to the dry weather, but now that we have had some rain, they will become active again. Slugs sometimes leave a shiny trail where they travel at night that may be observed during the day, but their presence can be positively confirmed by leaving a piece of fruit such as a watermelon rind or a half of an orange outside overnight. The slugs will often hide under the fruit during daylight hours. A wooden board laid near the affected plants will also provide daytime hiding places for slugs. There are both organic as well as conventional slug poisons available at your local garden center. It is very important to make sure the product you choose is safe to use on vegetables, since some products are specifically labeled for ornamentals only.

Don’t rush to treat for bugs

The hot, dry weather we had up until last week was also conducive to flea beetles. Flea beetles, which hop like fleas, make lots of tiny holes in the leaves of many different types of plants, but they especially seem to favor tomatoes, potatoes and eggplant. Most transplants will outgrow the damage and it is often not necessary to apply any type of pesticide. Don’t be in too much of a rush to treat for insects at this time of the year. It takes time for plants to become fully established in the landscape but once they do, they are pretty resistant to most insect pests. There are a couple of major exceptions to this such as cabbage worms and cucumber beetles. These pests often require pesticide applications but both organic as well as chemical products are readily available for consumers. Make sure you read and follow all label directions when using any pesticides, even organic products.

Return to top

Click here for digital edition
2015-06-17 digital edition