Trap Crops Help Combat Pests in the Garden

Trap Crops Help Combat Pests in the Garden

Use traps crops, such as sunflowers and sorghum, to lure pests away from your crop. Photo by Molly Jameson.

Use traps crops, such as sunflowers and sorghum, to lure pests away from your crop. Photo by Molly Jameson.

To be a successful gardener, it is important to have an integrated approach to handling obstacles in the garden.

Aphids were lured into this sorghum seed head, which then attracted mealybug destroyer larvae, which are excellent garden predators. Photo by Les Harrison.

Aphids were lured into this sorghum seed head, which then attracted mealybug destroyer larvae, which are excellent garden predators. Photo by Les Harrison.

These considerations include techniques such as planting disease resistant crop varieties, maintaining proper plant spacing, planting at the appropriate time, monitoring the garden and properly identifying insects and diseases, watering uniformly, and many more cultural and preventative measures that will aid in a garden’s success.

As we transition from the relatively mild and dryer days of late spring into the hot and humid punishing days of summer, we often encounter more and more problems in our gardens.

Insects are commonly one of the main challenges we face, as warm temperatures and high humidity promote the growth and expansion of insect populations. To keep pests in check, it is important to consider all our options. If we turn too quickly to chemical controls, we will often encounter insecticidal resistance over time and our beneficial insect populations will be negatively affected.

One alternative to chemical controls to help combat destruction of our crops is by planting trap crops. Trap crops are plants you grow that the insect pest prefers for food and egg laying over the crops you grow that you plan to harvest. These trap crops attract harmful insects, luring them away from your garden veggies.

Sunflowers can attract leaf-footed bugs away from tomatoes. Hand pick and squish any that you see for better control. Photo by Molly Jameson.

Sunflowers can attract leaf-footed bugs away from tomatoes. Hand pick and squish any that you see for better control. Photo by Molly Jameson.

One effective trap crop example, which has proven effective in research studies, is using the combination of sorghum and sunflowers to lure leaf-footed bugs away from your tomatoes. If left unchecked, large clusters of leaf-footed bugs will feed and mate on developing tomato fruit, leaving your tomatoes discolored and distasteful. For tomato growers, it is worth the effort to plant both sorghum and sunflowers about two weeks ahead of your tomato crop. The blooming heads of the sunflowers will lure the leaf-footed bugs in. Hand pick and squish both adults and nymphs off of the sunflowers to help cut back on their populations. As the sunflowers die back, sorghum heads start to emerge, giving you enough time to harvest your tomatoes while the leaf-footed bugs feed on the sorghum panicles.

Another effective trap crop example is to grow blue Hubbard squash at least two weeks ahead of cucurbit crops, such as zucchini, summer squash, or cucumbers. The blue Hubbard squash acts as the trap crop, luring cucumber beetles, squash bugs, and squash vine borers away from the crop.

Buckwheat flowers attract pollinators and predatory insects into the garden. Photo by Janis Piotrowski.

Buckwheat flowers attract pollinators and predatory insects into the garden. Photo by Janis Piotrowski.

Trap crops are also a great tool for drawing in pollinators and natural predators of insect pests into your garden. For example, sweet alyssum and buckwheat flowers attract wasps and hoverflies. The wasps will lay their eggs on caterpillar pests, and when the eggs hatch, the wasp larvae eat the caterpillars as they mature. Hoverflies will lay their eggs on the leaves of the trap crops, which will hatch and feed on mealy bugs and aphids. Additionally, bees will be attracted to the trap crop flowers, introducing more and more pollinators into your garden.

When it comes to being a successful gardener, it is important to have an integrated approach. When cultural and preventative gardening techniques are combined with biological control techniques, such as trap cropping, your garden will be more resilient to pests and diseases, and you will be less reliant on chemical control methods, which should be seen as a last resort.

The Flower Power of Garden Flies

The Flower Power of Garden Flies

While we think of most flies as pests, garden flies, such as Allograpta obliqua species found in Florida, are excellent pollinators and predators of insects. Photo by Jessica Louque, Smithers Viscient, Bugwood.org.

While we think of most flies as pests, garden flies, such as Allograpta obliqua species found in Florida, are excellent pollinators and predators of insects. Photo by Jessica Louque, Smithers Viscient, Bugwood.org.

 

While our sentiments toward flies usually involve fly swatters, believe it or not, not all flies are nuisance pests! Some types of flies can actually be quite helpful in the garden.

These garden flies are nothing like your typical pesky house fly. While house flies and garden flies are both insects in the order Diptera, they are not in the same insect family, which is the next classification down in Linnaean taxonomy.

The nectar-loving garden flies that specifically visit flowers are in the family Syrphidae and are known as Syrphid flies, hoverflies, or flower flies. Although not as well-known in the pollinating world, there are almost 900 species of flower flies in North America, and they can be very colorful and eye-catching in the garden.

Allograpta obliqua flower fly adults are small and have bright yellow and black crossbands on their abdomens. Photo by Susan Ellis, Bugwood.org.

Allograpta obliqua flower fly adults are small and have bright yellow and black crossbands on their abdomens. Photo by Susan Ellis, Bugwood.org.

One of the most common flower flies in Florida is the species Allograpta obliqua. Members of this species, also called hoverflies, are often mistaken as fruit flies, and can therefore be perceived as harmful. But to the contrary, adults cross pollinate many flowers, and hoverfly larvae feed on predators, such as aphids that attack vegetables, fruit trees, cotton, ornamentals, and many wild plants. In fact, when there are numerous hoverfly larvae present, they can reduce aphid infestations by 70 to 100 percent!

Allograpta obliqua adults can be hard to spot, as they are a mere six-to-seven millimeters in length. Although small, they have distinct bright-yellow and black crossbands on their abdomen and become particularly abundant in the spring and summer here in the Florida Panhandle.

So, before you go swatting at any ole fly you see, remember that flower flies are our allies in the garden. Adults will aid in the pollination of our crops and landscape plants, and larvae will help defend our spring and summer veggies from the devastation of harmful insect attacks.

Learn more about Allograpta obliqua hoverfly species at the UF/IFAS Featured Creatures website (https://entnemdept.ufl.edu/creatures/beneficial/hover_fly.htm).

 

What to Do in the Garden in March and April

What to Do in the Garden in March and April

Variegated shell ginger is a good choice for adding color to shaded areas of the landscape. Photo by David W. Marshall.

Variegated shell ginger is a good choice for adding color to shaded areas of the landscape. Photo by David W. Marshall.

 

 

What to Do in the Garden in March and April

Written by David W. Marshall, UF/IFAS Leon County Extension Agent Emeritus

Except for a couple of freezes, it has been a relatively mild winter. But those freezes were cold enough and long enough to kill many tropical plants almost to the ground. Will we have more freezes? It’s possible, though after we reach mid-March, the probability drops significantly.

Some plants, such as this firebush, had stems killed back to the ground by the cold and will re-sprout from the root system. Photo by David W. Marshall.

Some plants, such as this firebush, had stems killed back to the ground by the cold and will re-sprout from the root system. Photo by David W. Marshall.

So, when can you start cleaning up all the cold damaged plants? You probably have the urge to do it as soon as possible, as the brown foliage and stems are a little depressing. Many of us have lots of cold-damaged plants and we want to get the cleanup finished. First, though, examine the plants to determine the extent of the cold damage. Scrape the bark with your fingernail or use a pocketknife to see if the tissue beneath is still green or if it has turned brown due to cold damage. In many cases, you will find that the stems have been killed back to within a foot of the ground. On other plants, you may find that some of the stems still appear green higher up and you may not have to cut them back quite as far. If that’s the case, you may wish to wait until mid-March to cut these plants back. In case we have another hard freeze, the damaged growth may offer a little insulation to the undamaged parts of the plant. With most plants there’s no real need to cut them back until the new growth starts popping out, probably in late March.

The stems of butterfly gingers can be completely removed now. Many of these will just pop off when pulled lightly. Others may have to be cut, but it won’t hurt them. Variegated shell gingers, in many cases, will still have some undamaged growth mixed in below the brown leaves. You won’t kill a well-established shell ginger by cutting it back now, but because of the insulating effect of the brown leaves, it’s probably best to wait until mid-March to cut them back.

Azaleas and camellias, typical of a North Florida spring, were blooming by late February this year. If you don’t have some of these in your yard, now is a good time to plant. Photo by David W. Marshall.

Azaleas and camellias, typical of a North Florida spring, were blooming by late February this year. If you don’t have some of these in your yard, now is a good time to plant. Photo by David W. Marshall.

You may have other shrubs that you wish to prune now also. Wait to prune spring bloomers like loropetalum and azalea until after they finish flowering. Some overgrown shrubs may need to be cut back hard to rejuvenate them, and if you do it now, they will have longer to recover. Before crepe myrtles start putting out new leaves, work on the shape of the tree. Remove poorly placed rubbing and crossover branches by cutting all the way back to the trunk or branch from where they grow. Don’t, however, top the tree unless you are purposely trying to pollard the tree and completely understand how to do it correctly. Otherwise, you will likely end up with a mess.

In mid-March, be prepared to plant warm-season vegetables such as tomatoes, snap beans, pole beans, lima beans, sweet corn, southern peas, squash, and watermelons. So, make sure you have the garden tilled before then. If you wait until April or May to plant, your harvest will be later and the insect and diseases will get much of the crop. Warm-season herbs can be added after mid-March.

Don’t be overly anxious to fertilize your lawn, especially if you have centipede grass. Wait until at least mid-March. Make sure the lawn has been fully green for three weeks before fertilizing. If this pushes you into April, fine. It’s better to fertilize too late than too early. Centipede lawns that are fertilized too early often have spring yellowing problems. St. Augustine grass is more forgiving, but don’t fertilize it either until at least mid-March. Use 6.7 pounds of 15-0-15 fertilizer per 1,000 square feet of lawn area. If the fertilizer doesn’t contain at least a third of its nitrogen in a slow-release form, though, cut the application rate in half.

Most of the weeds in the lawn now are winter annuals that will die out as the weather gets hotter. Just keep your lawn mowed regularly until they do. If you usually still have problems with weeds in the summer, though, you could use a pre-emergent herbicide to reduce the emergence of the summer weeds.

To keep fire ants out of your yard, broadcast a bait formulated product over the entire yard, according to the label directions. Plan to treat again in fall. You can quickly apply the bait using a small hand spreader available from your garden center.

Now, before it gets hotter, add some colorful camellias to your landscape. Photo by David W. Marshall.

Now, before it gets hotter, add some colorful camellias to your landscape. Photo by David W. Marshall.

Now, before it gets hotter, add some colorful azaleas, camellias, roses, and loropetalum shrubs to your landscape. Also consider fragrant plants such as tea olives, banana shrubs, and sweet viburnum. The sooner you plant these in the spring, the quicker they will get established and grow.

Lavender trumpet vine (Clytostoma callistegioides), crossvine (Bignonia capreolata), coral honeysuckle, and Confederate jasmine are vines that flower during this period of the year. Now is a good time to plant them also.

Don’t forget groundcovers such as liriope, Lomandra, Mondo grass, Dianella (New Zealand flax), African iris, or any of a variety of ferns. Groundcovers planted now will have a full growing season to get established. Groundcovers are often a good choice for plantings in front of the house where you don’t want tall shrubs.

Add some long-blooming seasonal color to your yard this spring. Once we reach mid-March the nurseries will be loaded with many possibilities. Petunias will give you a lot of color in sunny areas for about three months. After the summer rains start in June they normally decline. Pentas will hold up on through the summer and into fall. They prefer full sun but will take a little filtered sunlight too. Sunpatiens® will work in sun or shade and should hold up through the summer. Melampodium will give continuous yellow blooms in sunny areas through summer and into fall. Torenias, especially the trailing or vining types, are excellent for providing low-growing color in areas that receive morning sun but not so much harsh afternoon sun. But there are many other options, too, so visit a full-service nursery with knowledgeable employees that can guide you.

Pentas can be planted in mid to late March and will give color until late fall. Plant in full sun to light shade. Photo by David W. Marshall.

Pentas can be planted in mid to late March and will give color until late fall. Plant in full sun to light shade. Photo by David W. Marshall.

Also, later in the month, start planting perennials such as firebush, angel’s trumpet, cigar flower, and Turk’s cap so you will have color later in the season that will last into fall. These perennials will return each year, even if the tops get frozen back.

There’s no need to fertilize mature trees and shrubs that are growing well. But young plants which you’re trying to encourage to grow will benefit from an application of fertilizer now. The same 15-0-15 that you used for the lawn can be used on trees and shrubs, provided it’s not a weed-and-feed product with an herbicide. The exception would be with palms, especially if you’ve noticed that your palms haven’t been looking that healthy. Use an 8-2-12 or similar palm fertilizer that has four percent magnesium and micronutrients also. If you have a lot of palms in the lawn, just use this palm fertilizer on your whole lawn.

If you didn’t get around to fertilizing fruit plants in February, do it now. After mid-March is also a good time to plant new citrus trees such as satsuma, orange, or grapefruit. You have a full growing season ahead!

Anything that you plant now will need regular watering. That’s what they were receiving in the nursery. Remember that for several months, at least, all the roots will still be in the root ball that was in the pot, even after you put the plant in the ground. So, soak this root ball at least every other day. Don’t rely on a sprinkler system that only comes on once or twice a week. That’s not enough water for the limited root systems of new plants.

Written by David W. Marshall, an Extension Agent Emeritus with UF/IFAS Extension Leon County.

 

 

Leon County’s Spring Seed Library Program Starts February 12

Leon County’s Spring Seed Library Program Starts February 12

Join us via Zoom on Saturday, February 12, for our Leon County Seed Library Virtual Workshop. Graphic by Molly Jameson.

Join us via Zoom on Saturday, February 12, for our Leon County Seed Library Virtual Workshop. Graphic by Molly Jameson.

Believe it or not, spring is right around the corner! For gardeners, this is the time to start thinking about our spring season garden plan and starting seeds. Many spring vegetables, such as tomatoes, benefit from an early start indoors or in a greenhouse, planted in containers. This gives them a greater chance to avoid the intense heat of summer and beat many insect and disease life cycles.

Need seeds to start your garden? Well, if you live in Leon County, you are in luck. Starting Saturday, February 12, 2022, residents of Leon County can “check out” up to three sample seed packets per month with their library card as part of Leon County’s Seed Library Program. The vegetable seeds can be checked out from any of the seven library branch locations. Leon County residents can apply for a library card online at the LeRoy Collins Leon County Public Library online card application page (https://lcpl.ent.sirsi.net/custom/web/registration/).

Here are the vegetable seed varieties that will be available starting February 12:

  • Mammolo Basil. Mammolo basil has an Italian aroma and a bushy, compact growth habit that is great for containers.
  • Maxibel Haricot Vert Beans. Maxibel Haricot Vert produces prolific beans with long, slender pods and tender texture.
  • Natsu Fushinari Cucumbers. Natsu Fushinari is a deep green Japanese-type of cucumber with eight-inch fruit and glossy skin. It has resistance to diseases in high heat.
  • Little Fingers Eggplant. Little Fingers eggplant produces clusters of tender, long, deep purple fruit that can be harvested small or large.
  • Pinkeye Purple Hull Southern Peas. Pinkeye Purple Hull Southern is a semi-bushy, early-season pea that produces prolific dark purple pods. It has resistance to many diseases.
  • Bull Nose Peppers. Bull Nose is an old pepper variety, dating back to the mid-to-late 1800s, and has medium to large, sweet fruit that is great for cooking or salads.
  • New Zealand Spinach-like Greens. New Zealand spinach is not a true spinach, but it loves the heat and produces succulent leaves that are excellent cooked or fresh in sandwiches.
  • White Scallop Squash. White Scallop is a high-yielding Native American heirloom that produces scallop-shaped fruit great for frying or baking.
  • Homestead 24 Tomatoes. Homestead 24 is a semi-determinate tomato that has medium to large red fruit developed for hot, humid climates, making it great for Florida gardens.
  • Amy’s Sugar Gem Tomatoes. Amy’s Sugar Gem grows tall, vigorous vines and produces sweet, large red cherry tomatoes.
  • Moon and Stars Watermelon. Resembling the night’s sky, Moon and Stars watermelon has a dark green rind with bright yellow spots. It has speckled yellow leaves and seedy, but very sweet, bright red flesh.

Whether you are located in Leon County or not, everyone is welcome to join us Saturday, February 12, from 10:00 a.m. to 12:00 p.m., for our Leon County Seed Library Virtual Workshop. Via Zoom, agents with UF/IFAS Extension Leon County will discuss spring vegetable gardening techniques and healthy eating. There will also be a live cooking demonstration showing how to prepare healthy meals and snacks at home, featuring vegetables available in the Spring 2022 Seed Library Program.

For more information about the Leon County Seed Library Virtual Workshop, please visit our Eventbrite page: https://seedlibraryworkshop2022.eventbrite.com. There is no cost to attend the workshop, but registration is required.

Happy spring gardening!

Protect Your Winter Garden and Landscape Plants with Frost Cloth

Protect Your Winter Garden and Landscape Plants with Frost Cloth

Use frost cloth to completely cover cold sensitive plants. Be sure to make complete contact with the ground and use heavy objects to keep the fabric secure. Photo by Jonathan Burns.

Use frost cloth to completely cover cold sensitive plants. Be sure to make complete contact with the ground and use heavy objects to keep the fabric secure. Photo by Jonathan Burns.

 

One major aspect that separates North Florida from South Florida is the discrepancies in air temperature. Although the differences are relatively small when comparing Florida with northern states, they can mean a world of difference in the plant world.

Even hardy cauliflower leaves can be damaged by cold winter nights in the Florida Panhandle. Photo by Molly Jameson.

Even hardy cauliflower leaves can be damaged by cold winter nights in the Florida Panhandle. Photo by Molly Jameson.

In most of North Florida, our USDA plant hardiness zone is 8b, which means average minimum winter temperatures are between 15 and 20° Fahrenheit (F). We therefore can experience hard freezes, which happens when temperatures are below 28°F for over five hours. These types of conditions are capable of “burning” the leaves of even the toughest winter vegetables.

Fortunately for our winter gardens, average minimum winter temperatures are in the lower 40s, high enough not to damage winter garden crops. When we do have lows close to or below freezing (32°F), there is one very cost-effective method that can help keep crops and landscape plants protected. This is the use of a material called frost cloth.

Frost cloth can moderate air temperatures six to eight degrees. Photo by Turkey Hill Farm.

Frost cloth can moderate air temperatures six to eight degrees. Photo by Turkey Hill Farm.

Frost cloth, which can be purchased at most plant nurseries, is a breathable polyester fabric that is light weight and heat retentive. When used correctly, it can moderate air temperatures about six to eight degrees. This is typically all that is needed to get us through our mild North Florida winters. It is also relatively inexpensive, and if cared for, the same cloth can be used for many winter seasons.

Large blankets or bedsheets can be used as frost cloth substitutes, but whether you are using actual frost cloth, or something pulled from the linen closet, it is very important to use it correctly to be effective. The cloth must touch the ground at all points, as it works by trapping heat that radiates from the soil. It also increases the humidity around the plant, aiding in temperature moderation.

"Lollipop" trees will allow the heat from the ground to escape, giving the tree no cold protection. Photo by Jonathan Burns.

“Lollipop” trees will allow the heat from the ground to escape, giving the tree no cold protection. Photo by Jonathan Burns.

For sensitive landscape plants and fruit trees, it can be more difficult to fully cover the plant with the frost cloth to trap the heat, but it is just as important. When driving around town on a cold night, I inevitably encounter a few “lollipop” trees. This is when the foliage of the tree is wrapped in frost cloth, but the cloth does not reach the ground, and is typically tied off at the upper trunk of the tree. All heat moving upward from the soil will go right around the cloth, giving the tree essentially no protection.

Wire or PVC hoops can be used to help secure frost cloth and keep the cloth from damaging sensitive plant stems and leaves. Bricks, sticks, soil, or garden staples should be used along the perimeter of the frost cloth to prevent nighttime gusts from blowing the cloth off your garden beds or landscape plants. In the morning, remove the cloth once air temperatures reach about 50 to 60°F.

To learn more about cold protection, check out the UF/IFAS EDIS publication, Cold Protection of Landscape Plants (https://edis.ifas.ufl.edu/publication/MG025).