August heat brings out spike in population of these giant caterpillars
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The tomato hornworm's coloring makes it hard to see among tomato leaves. Look
for its poop on leaves below or, at night, search using a UV flashlight. (Photo: Debbie Arrington)
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They look like something out of a sci-fi movie – if you can spot them. And what they do to tomato plants is absolutely horrifying.
Recent hot, dry weather brought out a late-summer surge of one of the biggest bugs in our vegetable gardens: The tomato hornworm.
They love these last days of summer – and munching away on ripe tomatoes. While many critters retreat in high heat, these invaders actually spike in numbers and activity as the mercury rises.
Natural enemies usually keep their populations under control. But hornworm numbers tend to go up in August along with the temperature.
I saw this firsthand in my own Sacramento garden. I've picked off five hornworms from my tomato vines in five days.
Fat as a finger and just as long, hornworms rank as Sacramento’s largest caterpillars. They eat big bites out of their favorite food: Juicy tomatoes. They’ll also eat hard green tomatoes, leaves and stems.
Their stripes let them hide in plain sight. They blend in so well with their surroundings, they can seem impossible to spot.
What’s easy to see are leaves that have been stripped bare to the stem and damaged tomatoes. Other pests and critters may take bites out of tomatoes, but those stripped leaves – especially if the damage seems to appear overnight – usually indicate hornworms.
If you suspect hornworms, look for their poop. They leave large black or green droppings on or around the plant. If you see those droppings, carefully inspect the plant’s nearby leaves and stems. When you find it, pick off the hornworm and dispose of it. (Folks who raise chickens say their hens love them as a snack.)
If the hornworm escapes capture, it burrows into the soil and pupates into a moth of equally gigantic proportion: The hawk moth. Emerging in spring, this brown and gray moth has a 5-inch wingspan.
Rototilling the tomato bed after harvest prevents those moths from ever developing – and laying eggs next spring.
For more on tomato hornworms: http://ipm.ucanr.edu/PMG/GARDEN/VEGES/PESTS/hornworm.html
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Garden Checklist for week of Nov. 3
November still offers good weather for fall planting:
* If you haven't already, it's time to clean up the remains of summer. Pull faded annuals and vegetables. Prune dead or broken branches from trees.
* Now is the best time to plant most trees and shrubs. This gives them plenty of time for root development before spring growth. They also benefit from fall and winter rains.
* Set out cool-weather annuals such as pansies and snapdragons.
* Lettuce, cabbage and broccoli also can be planted now.
* Plant garlic and onions.
* Keep planting bulbs to spread out your spring bloom. Some possible suggestions: daffodils, crocuses, hyacinths, tulips, anemones and scillas.
* This is also a good time to seed wildflowers and plant such spring bloomers as sweet pea, sweet alyssum and bachelor buttons.
* Rake and compost leaves, but dispose of any diseased plant material. For example, if peach and nectarine trees showed signs of leaf curl this year, clean up under trees and dispose of those leaves instead of composting.
* Save dry stalks and seedpods from poppies and coneflowers for fall bouquets and holiday decorating.
* For holiday blooms indoors, plant paperwhite narcissus bulbs now. Fill a shallow bowl or dish with 2 inches of rocks or pebbles. Place bulbs in the dish with the root end nestled in the rocks. Add water until it just touches the bottom of the bulbs. Place the dish in a sunny window. Add water as needed.
* Give your azaleas, gardenias and camellias a boost with chelated iron.
* For larger blooms, pinch off some camellia buds.
* Prune non-flowering trees and shrubs while dormant.
* To help prevent leaf curl, apply a copper fungicide spray to peach and nectarine trees after they lose their leaves this month. Leaf curl, which shows up in the spring, is caused by a fungus that winters as spores on the limbs and around the tree in fallen leaves. Sprays are most effective now.
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