Category Archives: Garden Advice

Aphids, Scale Insects, & Mealy Bugs

Pests can be the bane of many gardeners’ existence and can be especially difficult to cope with if you’re new to gardening. Three pests that commonly make an appearance on a variety of plants include aphids, scale insects, and mealybugs. While they’re three different insects they all attack plants the same way, by feeding on its sap. You’ll find them along the stem and underside of the leaves where they suck the plant’s sap and drain it of important nutrients. They also secrete a substance called “honeydew” which can cause sooty mold to grow on your plants in severe cases.

You may have one of these insects feeding on your plants if you notice wilted, curled, yellow, or misshapen leaves, and water and nutrient issues aren’t the cause. You may also notice “honeydew” a sticky substance on the stem or leaves or the sooty mold that sometimes grows on it. These insects can also spread diseases between plants. 

Aphids

Aphids are tiny, pear-shaped insects with long antennae. Different species are a variety of colors including green, brown, black, pink, white, yellow, and gray. They’re typically wingless though as populations increase many species have a form with wings that can be used to spread and create new colonies.

Scale Insects

Like aphids, scale insects are small and come in a variety of colors in eluding green, brown, tan, yellow, orange, and black. Unlike, aphids they lack antennae and just look like a tiny rounded shell. Their shell means that they’re hard to eliminate as adults because it protects them from most natural pest control methods. However, they’re much easier to eliminate at their “crawler” or nymph life stage before they’ve developed their hard shell.

Mealy Bugs

Mealybugs are white and fluffy and sometimes look like little tufts of cotton or mold. They may look larger when they’re all together in a clump.

How to Prevent/Eliminate Them

Attract or introduce their predators.

As mentioned in a previous post, ladybugs feed on these insects. Ladybugs also need to feed on pollen to reproduce. Including flowers like coreopsis, cosmos, and yarrow in your garden can help attract them. You can also let some of your vegetables and herbs like basil, dill, and lettuce go to flower for them. Ladybugs can also be purchased commercially and released into your garden.

Avoid over-fertilizing.

These insects are all much more likely to infest plants that have high nitrogen levels. Especially if you use chemical fertilizer, be judicious with the amount you use because it may do more harm than good!

Spray them off with water.

Especially if you catch an infestation early, you may be able to get rid of these insects by spraying them off with water. 

Use a little soap.

Spraying your plants with a mixture of 1 tsp of dish soap in 1 quart of water is often effective. You should reapply the spray every 2-3 days for 2 weeks, ensuring you get all the surfaces of the plant.

Try neem oil spray.

Neem oil is a non-toxic, organic pesticide. Most neem oil products come with instructions for mixing (ie. 2 tbs of neem oil per 1 gallon of water). Try spraying all the surfaces of your plant once a day for 7-14 days.

Dab them with rubbing alcohol.

If the infestation is small you can remove these insects with a bit of rubbing alcohol on a cotton swab or rag. 

Dust your plants with diatomaceous earth.

Diatomaceous earth is a powder made from the crushed remains of diatoms, tiny, fossilized aquatic organisms. It cuts through the exoskeleton of many insects and causes them to dehydrate. Just remember, it can harm beneficial insects as well. Avoid using it when plants are in bloom as it can harm pollinators.  

Prune off the affected areas.

If you caught the infestation quickly you may be able to prune off the affected branches and burn them to prevent the insects from spreading.

Last Chance Sowings

Gentry yellow squash. Photo Pam Dawling

In our climate zone (7), with an average first frost date of October 14, the first half of August is the last chance to sow several vegetables and get crops from them before winter. Depending on your zone, your dates might be earlier or later. Planning and timing are crucial – if germination fails, you may not get a second chance with that vegetable. Planting now provides fresh harvests, storage crops and possibly some crops to overwinter.

There are three categories of vegetable crops to plant at this time of year:

  • Warm weather crops, now or not until next year.
  • Cool weather crops that grow well in spring and fall, but don’t thrive in the summer.
  • Cold-hardy crops to grow during the winter.

Warm Weather Crops 

Provider beans. Photo Pam Dawling

Give yourself a reasonable chance of success! We sow our last edamame 7/14 and our last sweet corn 7/16. We sow our last beans 8/1-8/3, and zucchini, summer squash and cucumbers by 8/5 at the latest. 

In many parts of the country, a frost or two will be followed by a few more weeks of warm weather, so getting past the first few frosts is worth the effort. It’s easy to get extra harvests for a month or two from mature plants you already have. See my blog post on Succession Planting for working back from your frost date to determine your last worthwhile planting date. Pay attention to the weather as you approach your average first frost date, and be ready to harvest mature crops and protect plants with rowcover.

Cool Weather Spring and Fall Crops 

Tatsoi. Photo Kathleen Slattery

The flavor of crops produced during warm sunny days and cool nights can be a delightful combination of sweetness and crunchy succulence. Some cool-weather crops mature in 60 days or less. Mostly these are greens and fast-growing root vegetables. 

Tokyo bekana. Photo Twin Oaks Community

Ready in 30–35 days:

  • kale, arugula, radishes, 
  • many Asian greens: Chinese Napa cabbage, Komatsuna, Maruba Santoh, mizuna, pak choy, Senposai, tatsoi, Tokyo Bekana and yukina savoy. 
  • spinach, chard, salad greens (lettuce, endives, chicories) and winter purslane. 

 

 

Ready in 35–45 days:

  • corn salad, land cress, sorrel, parsley and chervil. 

Ready in 60 days:

  • beets, collards, kohlrabi, turnips and small fast cabbage (such as Early Jersey Wakefield)

We have a chart for fall harvest crops so that we don’t have to calculate each time. It helps us ensure we don’t sow too late to get a decent harvest.

Sowing Dates for Fall Crops with Various Days to Maturity

Early Purple Vienna Kohlrabi takes only 60 days from sowing to harvest in spring. Allow for the slowing rate of growth in fall (unless you will use rowcover). Kohlrabi is hardy to maybe 15°F (-9.4°C). When is it likely to get that cold? Not before the beginning of November here, so counting back 31 days in October, plus 30 in September, plus 31 in August – that’s 92 days already, more than enough. We could sow kohlrabi in early August and get a crop at the end of October. 

We sow beets on 8/1, dry or presoaked for 1-2 hours in a little water – not too much, as they need to breathe, or could drown. We sow them 1/2″-1″ deep, tamp the soil, and keep the surface damp with daily watering for the 4-6 days they take to emerge. Beets prefer 50°F–85°F (10°C–29°C). I like the Cylindra beet. The shape is long (good for slicing), the skins come off easily, and the flavor is very sweet and the texture tender.

Very early in August, we sow our fall carrots, enough to store and feed us all winter. Danvers 126 is our workhorse carrot. We use an EarthWay seeder, which is light, easy to use and to empty, and comes at a reasonable price. 

Ruby Red chard. Photo Kathryn Simmons

Swiss chard can also be sown here in August, for a nice fall harvest. It germinates best at 85°F (29°C). It grows big leaves within 50 days of sowing, and smaller ones after only 35 days. We sow scallions outdoors on 7/25 and 8/23. Peas can make a god fall crop if started early enough to mature before frosts. 85°F (29°C) is optimum, 95°F (35°C) maximum. Peas are easy to pre-sprout. Mature pea plants are more easily killed by frost than seedlings. 

Spinach is a challenging crop in hot weather! Its optimum germination temperature is 70°F (21°C), maximum 85°F (29°C). To get around the problem of hot soils, you can wait until the soil temperature drops. The germination of purple dead nettle, henbit and chickweed are good phenology signs that it has cooled enough to sow spinach. Or you can pre-sprout seeds indoors as we do, and sow for on 9/1. 

Pre-sprouted spinach seeds and grits to mix in to make sowing easier. Photo Pam Dawling

Lettuce likes soils of 40°F–80°F (4°C–27°C) with 75°F (24°C) best. The maximum germination temperature is 85°F (29°C). For best emergence, wait until late afternoon or nightfall to sow lettuce. I put ice on top of hot weather lettuce sowings, and cover with shadecloth. Jericho romaine and the Batavian varieties are very heat-resistant. Sow: every 6-7 days in June and July; every 5 days in early August; every 3 days in late August; every other day until Sept 21; and, if you have a coldframe or hoophouse to plant them in, every 3 days until the end of September. 

Most brassicas will germinate fast at 86°F (30°C). The challenge is keeping the soil moist. For fall crops, we use an outdoor nursery seedbed and bare root transplants, because this fits best with our facilities and our style. Having the seedlings directly in the soil “drought-proofs” them to some extent; they can form deep roots and don’t dry out so fast. Other people might prefer to sow in flats. 

Young squash plants under ProtekNet insect mesh. Photo Pam Dawling

To avoid flea beetles and harlequin bugs, we cover the beds until the plants are big enough to stand up for themselves against “pest bullying”. We like ProtekNet insect mesh on wire hoops. Overly thick rowcover or rowcover resting directly on the plants can make the seedlings more likely to die of fungal diseases in hot weather – good airflow is vital. 

Radishes have no trouble germinating at high temperatures. We sow winter storing radishes 8/4: Misato Rose, Miyashige Daikon and Shunkyo Semi-Long. We also sow Easter Egg small radishes.

We aim to transplant most brassicas at four true leaves (3-4 weeks after sowing). In hot weather, use younger transplants than you would in spring, because larger plants can wilt from high transpiration losses. If we find ourselves transplanting older plants, we remove a couple of the older leaves to reduce these losses.

Large Early Jersey Wakefield cabbage with Swiss army knife for scale. Photo Pam Dawling

We sow broccoli and cabbage in June and July. August is too late for us to start those. Our main broccoli harvest period is 9/10 – 10/15. Among the Asian greens, we grow Blues Napa cabbage and sometimes Tokyo Bekana or Maruba Santoh for fall harvests. Komatsuna, senposai, yukina savoy and tatsoi are cold-tolerant greens we like for early winter harvests. We sow these to transplant mid-late July. 

Vates kale. Photo Nina Gentle

We sow 6 beds of kale, two each every 6 days, (8/4, 8/10, 8/16, 8/24) until we succeed in getting enough established. Often we’ll get patchy emergence and end up transplanting plants from one bed or one end of a bed to fill out the blank areas.

We sow our turnips 8/15 or up until 9/15 (our absolute latest). Turnips can be up the next day, even at 95°F (35°C). Rutabagas need longer than turnips, and need sowing in July. See Root Crops in July on my website for more about rutabagas.

Cold-Hardy Crops to Grow Over Winter

Morris Heading collard plant. Photo Kathryn Simmons

Find the winter-kill temperature of your desired crop, and choose hardy varieties. Be clear about whether you intend to harvest outdoors all winter (kale, spinach, leeks, parsnips, collards for us), or whether you want to have small crops going into winter so you can rest during the winter and be first out the gate in early spring, with crops waiting for you. We sow a couple of beds of spinach between 9/20 and 9/30 to overwinter small (under rowcover) and grow fast in the spring.

We have had some success with over-wintered carrots (sown 8/14) and cabbage transplanted 7/13 (Deadon is especially hardy). 

 

Pam Dawling has grown vegetables at Twin Oaks Community, central Virginia for 27 years, feeding 100 people from 3.5 acres.  She has written two books: Sustainable Market Farming and The Year-Round Hoophouse. She blogs weekly at https://www.sustainablemarketfarming.com

5 Predatory Insects Native to the Southeastern U.S.

When many people think of beneficial insects, they picture bees and butterflies that help to pollinate crops. Beyond pollinators, many insects play an important in improving garden yields. Some of these are predatory insects that keep garden pests in check. Here are five of the insects you may see in the Southeast that help keep your garden growing.

Arilus cristatus (Wheel Bug) 

This funky looking insect is a type of assassin bug. It feeds on a wide variety of prey, including aphids, caterpillars, stink bugs, Mexican bean beetles, locust leafminers, sawflies, and more. Wheel Bug salvia contains a potent toxin that quickly immobilizes and kills its prey.

The Wheel Bugs are distributed throughout the United States and parts of Mexico and South America. They have one generation per year and overwinter in the egg stage. They enjoy various habitats, including native flowers and forest and crops like sunflowers, cotton, and fruit and nut trees.

If you see these bugs in your garden, take care in handling them as they can deliver a painful bite to humans if disturbed.

Chrysopidae (Lacewing)

Lacewings are so effective as pest predators these guys can be purchased commercially to release into your garden. As adults, they mostly feed on nectar, pollen, and honeydew. As larvae, they’re voracious predators of soft-bodied insects like aphids and mites as well as insect eggs. Less frequently, they will eat caterpillars and some beetles.

There are actually about 2000 species of lacewings! They’re an enormous and widespread group found across North America and Europe. Lacewing eggs hatch in just a few days, and then the insect is in the developmental larva stage for 2-3 weeks, during which they prey on pests. Then they spin a silk cocoon, become adults, mate, and repeat their life cycle. A single female can live 4-6 weeks as an adult and lay about 200 eggs.

To encourage lacewings to reproduce in your garden, include flower plantings so that the adults have food sources.

Hippodamia convergens (Convergent Lady Beetle)

Photo from The University of Florida

Except for squash beetles and Mexican bean beetles, all members of the lady beetle or ladybug family are useful garden allies. One species common to the Southeast is the Convergent Lady Beetle. They’re ubiquitous predators of thrips, aphids, scales, and other soft-bodied insects. They’ll also eat the larvae of other insects like that of the asparagus beetle.

Like lacewings, the adults feed on nectar, pollen, and honeydew. The female needs a certain amount of food before depositing eggs. These lady beetles typically have two generations per year in the spring, summer, and fall. The larvae feed on other insects before developing into beetles.

Stagmomantis carolina (Carolina Mantis)

Photo from The University of Nebraska

The Carolina Mantis sits quietly and waits for any prey that happens by. They eat an incredible variety of other insects, including caterpillars, beetles, moths, flies, butterflies, wasps, and bees. They like herbaceous areas like meadows and gardens, as well as low shrubs.

They typically have one generation per year. The females create a small, tan, hardened egg case called an ootheca attached to a stem or twig. The case contains hundreds of eggs that overwinter and hatch out during the spring.

Argiope aurantia (Yellow Garden Spider)

Commonly found in gardens and meadows, these spiders build large beautiful, circular webs. They spend most of their time waiting for prey like moths and flies to fly into these webs. 

They breed up to twice a year. The male seeks out the female and courts her by plucking strings on her web. He typically dies or is eaten by her after mating. The female creates egg sacks filled with thousands of eggs and hangs them close to her, often in her web. She’ll guard them until she dies in the fall. In the spring, the young spiders hatch out.

How to Help Predatory Insects

Avoid pesticides. 

Pesticides are detrimental to all insects, including beneficial, predatory insects. Check out our organic pest management tips for alternatives and work to encourage these predatory insects in your garden.

Build an insect hotel.

Insect hotels are an easy way to create habitat for a variety of predatory insects and pollinators. Learn to create your own with our post, DIY Insect Hotel.

Plant flowers.

Flowers are essential food sources to many beneficial insects in different life stages. Planting even a small strip of flowers can help draw pollinators and predatory insects to your garden and encourage them to lay eggs there.

Keep your property as wild as possible.

As we’ve discussed in previous articles about beneficial birdsbees, and butterflies, keeping your property wild helps provide habitat. Proper habitat will encourage many valuable species to frequent your yard and garden. Let lawns grow tall, leave brushy areas, and don’t clean up dead plant material in the fall unless it has a severe pest or disease issue.