With spring on the horizon, many of us are planning or have already began to plant our spring gardens. If you’re still in the planning process like me, one very important thing to consider is the importance of crop rotation in the garden. Crop rotation is a concept that’s been used by farmers for many years but it’s a concept that gardeners need to adopt as well!
What is crop rotation?
Crop rotation is a method used to reduce insect pests, disease and manage soil fertility by changing the planting location of vegetables within the garden each season. Each vegetable is grouped into a plant family. Vegetables in the same plant family typically are able to harbor the same kinds of insect pests and diseases, and have the similar nutrient requirements. When vegetables belonging to the same plant family are planted in the same location over and over again, pest populations can build up and productivity of the garden decreases. In addition, fertility issues can arise from planting the same crops, in the same area over again. Since different crops require different types and amounts of nutrients, crop rotation can help even out the loss of soil nutrients.
List of common vegetable families.
How should I plan for crop rotation in my garden?
First, consider the vegetables you would like to grow this season then group them by their families. Vegetable crops in the same family should NOT be planted in the same area year after year. For example, if squash is planted in a bed or one area of the garden one year, cucumbers or watermelons should not be planted in the same area of the garden the following year because these plants belong to the same family (Cucurbitaceae).
Divide your garden according to the number of plant families you want to grow. This could be in rows or even separate beds. From there, you will want to think about your ordering sequence. For example, if you are planting a legume (beans or peas) that fixes nitrogen back into the soil this spring, you’ll want to plant a heavy feeding crop like broccoli this fall. Heavy feeding crops can be followed by light feeding crops such as carrots or onions. Be sure to keep a gardening journal as a reminder of what is planted each year and season.
Crop rotation is one of the most effective methods we have to manage the many pests and diseases we have here in Florida. If you’re struggling with a particular pest or disease in your garden, consider using crop rotation to help manage it. For more information on crop rotations for the home garden, contact your local extension agent.
Many gardeners plant a spring vegetable garden with a number of different vegetable types, which is excellent because a diverse and varied garden is proven to improve soil health. Intercropping is a gardening practice of growing different crops in the same field. When planting a mixture of crops in the same field year after year, it is important to rotate the location of each type of vegetable. This is a practice known as crop rotation. Intercropping and crop rotation will help reduce insect pest populations, increase beneficial insect populations, and reduce weed populations .
Crop Diversity
Including plants that pest insects don’t like to eat in a garden forces the pests work harder to find what they find palatable. Studies have found reduced whitefly numbers on squash plantings mixed with a crop of buckwheat when compared to squash planted alone. Another crop mixture that may be unintentional, but may be favorable, is a crapemyrtle stand along a garden’s edge. Crapemyrtles will attract the crapemyrtle aphid which will attract predatory insects. When the predatory insects run out of crapemyrtle aphids to eat, they will move to the vegetable garden and begin to hunt pest insects.
Squash with living mulch of buckwheat. Photo Credit: Oscar Liburd, UF/IFAS Extension
Trap Cropping
A trap crop is a plant that attracts a pest insect away from your food crops. Trap crops work best when planted at the garden’s edge, along a fence row, or in movable containers. A bare space, let’s say 5 feet or so, should be kept between trap crops and vegetable plantings. This will help keep the pests from moving desirable crops plants. When a large population of pests are found on the trap crop then it is time to spray them with insecticide, or cut the crop down and remove or destroy the debris. If trap crops are planted in containers, then it makes them much easier to remove from the garden when necessary.
Cover Crops and Green Manure
Soil organic matter can be increased by the use of green manure and cover crops. Cover crops are generally planted during the off-season, but they can be planted in between vegetable rows and tilled in at a designated time as a green manure. Both cover crops and green manure improve garden production by:
Suppressing weeds by competing for water, light, and nutrients;
Holding the soil in place and preventing erosion;
Scavenging for nutrients that can be utilized in future crops;
Reducing nematode populations;
Providing a habitat for beneficial insects.
A mixed plot of cover crops and trap crops. Photo Credit: Matt Lollar, UF/IFAS Extension – Santa Rosa County
A number of different crops can serve as cover crops or green manure crops. Most are legumes (bean family) or grasses. A few that should be tried are:
This tomato hornworm is being parasitized by beneficial wasps. Photo credit: Henry Crenshaw
Why would anyone allow dozens of wasps to thrive in their garden? Why would they let caterpillars keep moving through their pepper bushes? Don’t they know you can spray for that?
As Extension agents, one of the tenets we “preach” in gardening is the concept of Integrated Pest Management (IPM). This technique involves a series of insect control measures that begin with the “least toxic” method of control, using chemicals as a last resort. One of those least toxic measures is “biological control”, in which a natural predator or parasite is recognized and allowed to remove a pest insect naturally. It is important to be able to recognize some of the more common garden predators and parasites. Many times these insects look strange or dangerous, and they are mistaken for pests and killed.
One such beneficial insect to the home gardener is the braconid wasp (Cotesia congregatus). Most people shudder at the mention of wasps, but these tiny (1/8 inch long), mostly transparent wasps are of no danger to humans. Quite the opposite–they are an excellent addition to gardens, especially if you are growing tomatoes or peppers. One of the major pests to these favorite vegetables is the tomato hornworm (Manduca quinquemaculata), a fat green and white-striped caterpillar.
The beneficial wasp can control hornworms because females lay eggs under the caterpillar’s skin, after which the eggs hatch and larvae feed on the hornworm. After eating through the caterpillar, they form dozens of tiny white cocoons on the caterpillar’s skin. The tomato hornworm is rendered weak and near death, and the vegetable crop is saved.
If you happen to find a tomato hornworm covered in these small oval cocoons, consider yourself lucky. Let the process continue, allowing the new generation of beneficial wasps to hatch and continue their life cycle. They will control any future hornworms in your garden, and the whole process is fascinating to watch!
For questions on integrated pest management, beneficial insects, or growing peppers and tomatoes, call your local County Extension office.
A few months ago I visited a property that had been renovated to clean up some limbs that were in danger of falling on the house. Pruning tree limbs that are in danger of hitting a structure is always a good idea, but it’s important to look at the impacts this practice may have on the rest of a landscape. Any time the light profile of a landscape is changed, current and future plant selection must be considered. One often seen example occurs when trees grow to full size and shade out the lush lawn that’s underneath. However, in this case, removal of limbs allowed more light to shine on some beautiful, old camellia bushes.
Camellia Planting and Care
Camellias do best in locations that receive filtered sunlight and are protected from the wind. They like acidic, well-drained soils. Trees and shrubs are generally planted 2″ to 3″ above the soil grade. (2″ to 3″ of root ball should be exposed above the soil grade when the tree/shrub is planted.) To help improve root oxygen exposure and help prevent a root rot situations, camellias can be planted slightly shallower than the previously stated recommendation. For more plant establishment guidelines, please visit: UF/IFAS Planting and Establishing Trees Guide
Scenario and Diagnosis
As mentioned above, the property in question was visited to diagnose sick camellia bushes. Upon further inspection of the property, asking about recent changes to the landscape, and inspecting the bushes, it was clear that the camellias were receiving too much sunlight. Sunlight damage was expressed by large brown sunscald spots on the yellowing leaves.
Sunscald damage on camellia leaves. Photo Credit: Jed Dillard
The camellias had also been pruned incorrectly. Camellias require minimal pruning. They are normally pruned to control size or promote a tree form structure if desired. Any pruning should be done before flower buds form in late summer.
An incorrectly pruned camellia bush. Photo Credit: Jed Dillard
Solution
The best solution in this scenario was to dig up the affected camellias and move them to a location with more shade. Sun loving shrubs were suggested as options to replace the camellia bushes. It’s important to note that Camellia sasanqua cultivars are usually more tolerant of sunlight than Camellia japonica cultivars. The recommendations were based on the Florida Friendly Landscaping principle of “Right Plant, Right Place”.
If you’re trying to find the right plants for you own yard, then you should check out the Florida Friendly Landscaping Interactive Plant Database. The database gives you plant selection options for each area of your yard based on location in the state, plant type, and soil and light conditions.
A very popular landscape shrub installed by both professionals and homeowners is Loropetalum or Chinese fringe. This shrub offers attractive foliage and flowers along with being evergreen.
When you visit a nursery to select this plant for your landscape, realize that there are now many selections of Loropetalum available. Learn about a few of the common selections in this recording of ‘In the Garden’, with UF/ IFAS Extension Escambia County Horticulture Agent Beth Bolles, so that you are successful at matching the appropriate plant with your landscape needs.
Air potato leaf beetle attacking the invasive air potato plant.
Air potatoes got you down? Have no fear, for the Air Potato Challenge is coming to Leon County!
Register now to attend the Air Potato Challenge event on May 18, 9 a.m. to 12 p.m. at the FAMU Center for Viticulture and Small Fruit Research (6361 Mahan Drive, Tallahassee, FL) and receive a supply of air potato beetles to use on your property.
After years of testing, air potato beetles became available as a biological control in 2012 to help combat the invasive herbaceous perennial air potato vine (Dioscorea bulbifera). Air potatoes arrived in south Florida from China in the early 1900s and have steadily crept north until they are now invading the Panhandle Region. Fortunately, air potato beetles have dietary requirements that are very specific, relying strictly upon air potatoes to complete their life cycles.
This is why a team of researchers and Extension agents have come together to help spread air potato beetles as a biological control strategy. Many agencies and counties are involved in this effort, including UF/IFAS Extension St. Lucie County, UF/IFAS Indian River Research and Education Center, the Florida Department of Agriculture Division of Plant Industry, the USDA, Florida Fish and Wildlife, UF/IFAS Extension Leon County, and Florida A&M University.
