I saw the defoliated stems, the gnawed fruit, and the black droppings on the ground. It could mean only one thing: the Green Monster. Not to be confused with the famed left field wall at Fenway Park, this green monster is better known to vegetable gardeners as the tomato hornworm.
Seeing the damage inflicted on several of my tomato plants, I did a pat down of the plants, searching every stem and remaining leaves for the critter. No luck. You'd think that a caterpillar measuring up to 4 inches in length would be easy to find. Not so. It is well camouflaged with its tomato-leaf green color, white V-shaped markings along its body, and a horn-like projection from its tail end.
Just as I gave up the search, my daughter and co-gardener, Jennifer, walked up, pointed, and said "Wow! See that huge tomato hornworm, Dad."
What I said next is not allowable in print.
My instinct was to pick off the beast since hand picking is the easiest means of controlling hornworms -- that is, once you locate them. However, I quickly decided to leave the caterpillar alone.
"What, are you nuts?" you ask. Maybe, but this hornworm had white projections on its body. These protrusions are cocoons of a small wasp which had parasitized the hornworm. This caterpillar was headed for hornworm hell.
By leaving it on the plant, I knew that the adult wasps would soon emerge from the cocoons and seek out other hornworms to feed on. This is an example of Mother Nature at her best.
We'll be at our best working in the garden on these projects:
- Take cuttings of butterfly bush, forsythia, hydrangea, mockorange, viburnum, and weigela. Use a sharp knife (e.g., a box cutter), to cut 4 to 6-inch long shoot tips from these plants. Remove any flowers and all lower leaves on the cuttings. Dip cut ends of the shoots in a rooting hormone (Rootone and Hormonex are commonly available at garden centers). Stick the cuttings in a pot filled with moistened sand or a mix of peat and perlite. Cover the pot with a clear plastic bag and place it in bright but indirect light.
- Propagate woody herbs such as lavender, lemon verbena, rosemary, sage and thyme by taking cuttings as described above, except the cuttings should be 2 to 4 inches long.
- Check trees and shrubs for suckers (rapidly growing shoots) emerging from the base of their stems. Use hand shears to cut away the suckers. Grafted trees are most likely to produce suckers from their base.
- Place a thick layer of straw mulch under the developing fruit of winter squash, pumpkins and melons. This will help prevent rotting of fruit that is in contact with wet soil. Sometimes I just put an inverted can under each fruit to keep it off the soil.
- Try at least one more planting of fast-ripening vegetable crops such as leaf lettuce, spinach, arugula, radish, and bush beans. Garden centers may still have seeds available, usually at greatly reduced prices. Otherwise, ask your friends if they have leftover seeds.
- Look for the larva of squash vine borer inside the stem of wilted squash, pumpkin, and gourd plants.
In about eight weeks, the cuttings will have rooted and can be transplanted to the garden.
The larva is thick, white, wrinkly and about one inch long. The entry hole of the larva is typically found at the base of the stem. Use a sharp knife to make a length-wise cut into the stem, and remove and destroy the larva. Otherwise, the larva will soon leave the stem, burrow into the ground where it over-winters as a pupa (cocoon).
Next summer it will emerge as an adult moth which starts the cycle over again.