There is a saying that goes; if you build it, they will come. In the case of your vegetable garden, if you plant, it they will come, unwelcomed of course. They are caterpillars, the larvae of moths and butterflies. There are several different types of caterpillars and there are just as many ways to prevent or get rid of them from your garden. Caterpillars can cause major damage to fall vegetables, particularly kale, cabbage, broccoli, collards and cauliflower. Some species of caterpillars are known to kill seedlings and young plants if left untreated, but most species just enjoy munching on the leaves or fruits. If they are detected early it can be easy to control caterpillar infestations.
For caterpillars to infest your garden, first, a moth or butterfly must fly in and lay their eggs on the plants. The eggs may be laid in clusters or singly. A few days later tiny caterpillars will emerge and immediately begin to feed on the leaves. Then they will progressively grow larger and may change color. Most caterpillars feed for two to three weeks, before entering a cocoon. How long they remain in the cocoon is dependent on the type of caterpillar. It is very easy to detect a caterpillar infestation since they leave rugged holes in the plants, evidence of their feeding activity. If you notice holes in your crops then check both sides of the leaves for caterpillars.
To control a caterpillar invasion on your crops, lets start with some preventative measures. There is the option of covering crops with insect barriers. These special fabrics form a barrier, preventing moths and butterflies from landing on the plants and laying their eggs. If possible you could build a frame and place the fabric over the seedlings though a frame wouldn’t be necessary. The fabric is soft and flexible enough to be placed over the plants and, it allows adequate sunlight to pass through. Since most fall veggies are grown for their leaves, and roots don’t require pollination covering the plants will not reduce yields.
Spraying infested crops with an appropriate insect control product that contains organic and synthetic active ingredients such as pyrethrin, is another way to control caterpillars in your garden. These products are available at gardening centers. Pay attention to the pre harvest interval before applying any pesticides to your crops. This interval is the number of days you’ll have to wait, from the time you spray to the time you harvest. Intervals vary for different pesticide from 0 to 21 days or more. And, if you intend to use it on edible plants make sure it is safe for use on vegetables.
Hand pick them it is quite common for some gardeners to pick the caterpillar out of their garden, but this can be time consuming but each caterpillar pick out means one less moth or butterfly that will later lay eggs. Be careful when picking up caterpillars, some species have spines on their bodies that packs a nasty sting. Take a small bucket with you and put the caterpillars in and feed them as a treat to your pets. Or you could kill them by dropping them in some soapy water if squishing them is not your cup of tea.
Organic pesticides you could use bacillus thuringiensis, this is a naturally occurring bacteria that can be place in the garden. This bacteria is nontoxic to humans but lethal to caterpillars.
Pyrethrin is another organic pesticide that is extracted from the flower of the chrysanthemum, (not the common type grown in fall) pyrethrin will effectively control caterpillar infestation.
Neem oil is derived from the seed of the neem tree, a native of southern Asia. This organic oil can be spray on plants to control caterpillar infestation.