Heat, bugs causing issues in the garden
July 14, 2014
It's summer and we are seeing issues in the garden. Some vegetable problems are pest related, others are caused by improper watering or fertilizing and some are due to the environment.
A few of my English pea plants turned light brown and dried up. And although the pods are beautifully formed on the remaining healthy plants, the peas inside are often tiny. This is heat damage. I should have planted earlier. Although I fertilized with a slow-release fertilizer, peas probably need a fertilizer higher in phosphorus or potassium in order to grow bigger peas.
Lettuce, kale and chard are also declining and producing less due to the heat. Because the plants are stressed, I often find dense colonies of aphids on the undersides of leaves. Spinach, parsley and cilantro are all bolting due to the heat. This means flower stalks are developing, a sure sign it's too warm.
I am receiving calls about blossom-end rot on tomatoes where brown leathery patches occur on the bottom of fruit. This is caused by a lack of calcium, a result of slowed growth and damaged roots, possibly caused by extreme fluctuations in soil moisture, excessive salts in the soil or weeding too close to the stem and roots. To reduce blossom-end rot, water the plants consistently to keep them evenly moist. Mulch the soil to retain moisture. Avoid using high-nitrogen fertilizers or large quantities of fresh manure. If the soil is salty, water more deeply to leach the salts below the roots.
Don't be surprised to find huge green caterpillars on your tomatoes, peppers or eggplants. These are tomato hornworms, the larvae of sphinx moths. They eat the foliage and the fruit and then leave behind black pepper-sized droppings on the leaves. Pick the hornworms off by hand and dispose of them.
Many kinds of other caterpillars also eat plants. Cabbage loopers, the larvae of moths, chew holes in cabbage and lettuce leaves. Loopers are green worms about 1½ inch long with light stripes on their backs. They excrete brown or green droppings. They can be controlled by handpicking or spraying with a bacterial insecticide called Bacillus thuringiensis, or Bt. Bt should be applied when the caterpillars are small with treatments repeated weekly as damaged is noticed. Covering the plants with row covers at planting can prevent moths from laying eggs on the plants. Clean all plant debris out of the garden at year's end to eliminate hiding places for overwintering cocoons.
That's just to name a few vegetable problems.
JoAnne Skelly is the Carson City/Storey County Extension educator for University of Nevada Cooperative Extension and may be reached at firstname.lastname@example.org or 887-2252.