July Gardening Guide from the Arlington Virginia Cooperative Extension

Virginia Cooperative Extension

Between the Rows – A Guide to Vegetable Gardening

July in the Vegetable Garden Insects: The Good, The Bad, and The Sometimes Ugly

Welcome veggie gardeners! VCE supports local gardeners with a host of resources, including free classes, plant clinics and this newsletter. Want to know more? Subscribe here to receive future issues. Missed out on past issues? You can get them all here.

Garden Guide
July To Do List

  • Direct sow additional beans, cucumbers, beets, carrots, corn, and summer squash
  • Plant pumpkins and gourds for Fall harvest
  • For new plantings, follow instructions on the seed packet and count backwards from the first frost (mid- to late-November) to allow enough time for germination and growth
  • Harvest ripe fruit daily to help keep away unwanted pests, and remove/replace any dead finished vegetable plants
  • Continually harvest warm weather crops, such as tomatoes, okra, beans, beets, corn, cucumbers, melons and corn
  • Make sure tomatoes vines have room to grow and are properly supported; trim away yellowed foliage to let in sunlight and remove stems with no flower set that will not grow fruit
  • Harvest garlic, onions, and potatoes when tops turn brown and die back; cure root vegetables for a few weeks before storing
  • Visually check plants daily for early signs of pest infestation (such as squash vine borer holes in squash) or for early signs of plant disease (such as mildew on the leaves of cucurbits and melons)
  • Keep weeds in check to avoid competition for water and nutrient use by your vegetable crops
  • Take precautions in your garden to keep mosquito populations in check by removing possible breeding grounds, such as standing stagnant water in gutters, and by encouraging air and light circulation among plants
  • Continually deadhead herbs and leafy greens to encourage new growth
  • Place straw, cardboard, or wood chips under developing melons, pumpkin, and squash to elevate fruit off the ground to avoid rot and deter pests
  • Stop harvesting asparagus and rhubarb to allow the plant to regenerate and store energy for next year’s crop
  • Cover berry bushes and fruit trees with netting to protect your harvest; hanging shiny objects may also help ward off birds
  • Pinch back strawberry runners to allow plant to conserve energy and encourage root growth
  • Plant your sweet potato slips in the garden, mounding up so the roots have room to grow; amply space out the slips to allow the vines to grow and spread
  • Later in the month, plan to start seeds indoors for planting in the Fall, such as cabbage, broccoli, Brussels sprouts, cauliflower, collards, and kale

Plant, Pest or Other Garden Questions?
Contact the VCE Horticulture Help Desk 

Knowledgeable Virginia Cooperative Extension volunteers are available to answer questions Monday-Friday from 9am to noon.

By now you’ve realized that you’re sharing your garden with insects. The good news is that many of these insects are beneficial to your garden. Healthy gardens need and welcome pollinators, parasites (they lay eggs in harmful insects), and predators (they eat harmful bugs). These include: bees, butterflies, ladybugs, spiders, flies, parasitic wasps, lacewings, praying mantis, and ground beetles. To attract more of these helpful insects, vegetable gardeners often plant nectar-rich flowering plants, such as dill, mustard, sunflowers, Black-eyed Susans, parsley, and goldenrod, among their vegetables or nearby.

Consider incorporating certain aromatic flowering plants and herbs to deter and repel garden pests, including rodents and mosquitoes. Plants that may repel pests include marigolds, lavender, lemongrass, garlic, garlic chives, rosemary, basil, catnip, bee balm, petunias, and a variety of mints. Consider also making a plant extract in your kitchen, such as pepper or garlic sprays. Pepper or garlic sprays on melons help deter rodents from attacking growing fruit, and might also discourage other pests (and mosquitoes) from the garden. Adding soil amendments, such as blood meal, poultry grit, and eggshells, might also deter pests, such as slugs and squirrels. Other rough or sharp materials, such as Diatomaceous Earth, pine needles, or wood chips might also deter pests.

Most gardeners are hesitant to grab a pesticide once they think they’ve spotted an insect that appears to be causing plant damage, especially for use on edible plants. Some broad-spectrum insecticides kill not only unwanted pests, but also pollinators and other beneficial predator insects. Instead of applying pesticides, identify the insect to determine whether it’s a beneficial insect or a pest. Check out these resources to help you identify your insect visitor and cultural controls to minimize pests and disease. This interactive pest id guide on the most common vegetable garden pest also provides possible organic solutions to pest control. VCE guides for addressing pests common to Virginia are available here and here

Check your garden daily for pests and early signs of disease. Once you’ve determined you have a pest problem, try some less invasive methods of getting rid of your problem first. Strategies may include picking the offenders off your plants by hand, using a strong blast of water from a hose on the infected area/plant, or pruning away the damaged plant part. Try shaking plants above a bowl of soapy water or spray with a soapy water solution. Be also sure to remove any eggs or larvae left behind. If the problem persists, try some insecticidal sprays that are available at most stores with garden departments. Read more about preventing and treating pests in your garden here.

Be vigilant for any early signs of common vegetable garden diseases. If you discover, for example, mildew on your basil, cucumbers, and squash plants, act quickly: prune away the diseased bits (throw away, do not compost!); thin out the plant to allow for more air circulation; or remove the plant entirely to avoid spreading to other plants. Consider using disease resistant varieties of seeds and transplants for your garden, or growing alternate varieties (e.g., Thai or Lemon basil) that may be less susceptible to disease. Learn more about identifying and managing mildew on basil and cucurbit plants.

Remember, your Extension Office is ready to help you with your insect and plant disease problems!

Get to know your weeds. Weeds in your garden unnecessarily compete with your growing vegetable plants for available water and nutrients, and may shade plants from sunlight they need to grow. Some useful weed identification guides are available here and here.

Poor growing conditions in your garden may be difficult to diagnose. In general, reasons why your plants don’t thrive may be attributed to not enough sun, crowded conditions, too much or not enough nutrients, poor genetics or maturation, root stress, or buds hit by late frost. If your garden doesn’t have enough beneficial insects, some fruiting plants might also require help becoming pollinated. Some plants might need to be hand pollinated or might become pollinated by lightly shaking the plant.

If your garden is struggling because it is not getting enough sun, consider steps to grow plants and cultivate practices geared toward shadier gardens. Some steps you can take include optimizing growing conditions (such as soil preparation, selective pruning, adequate spacing, and targeted watering), choosing varieties that yield smaller fruit, growing in movable containers or vertically, using reflective mulch or surfaces, or growing in the winter when trees are bare and cast less shade. For a list of plants and tips see here.

Before adding fertilizer to your plants familiarize yourself with the signs and symptoms of nutrient deficiency and the so-called N-P-K ratio. The N-P-K ratio refers to the three primary macronutrients of nitrogen (N), phosphorous (P) and potassium (K) in plant fertilizers. For example, a commonly-used fish fertilizer for vegetable plants is labeled as 2-4-1 and, therefore, has 2% nitrogen, 4% phosphorous, and 1% potassium. A general rule of thumb for home gardeners is the expression “Up, Down, All Around” meaning nitrogen for green growth (up), phosphorus for root development (down), and potassium for all over health and vigor (all around). Make sure not too over apply these nutrients, especially nitrogen, which can burn roots and kill your plant.

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