Weed Control

Weeds in a garden

Everyone looks forward to that first ripe tomato or ear of corn picked from their own carefully tended gardens.  But after some vigorous hoeing on a hot humid day, some may be asking themselves if it is all worth it. 

Weeds compete with crop plants for water, nutrients and sunlight.  Some weeds, like quackgrass, can chemically inhibit vegetable plant growth.  Others host insect pests and pathogens.  All of these result in fewer fresh vegetables for your table. 

There are some preventive practices that effectively combat weeds.  Frequent hoeing or rototilling on a weekly basis helps eliminate weeds when they are small and easily removed.  By planting rows a little closer, vegetable crops provide more shade which also helps to reduce weed pressure.  After harvesting a crop, plant another in its place to continue using the space.

Mulching works very well in the home garden.  Use organic material such as grass clippings, leaves or straw to eliminate weed growth and build up organic matter to make the soil more fertile and friable.  Do not use grass clippings from a lawn that  was treated recently with the herbicide 2, 4-D.  Treated clippings can cause twisting of the vegetable plants and can even kill some sensitive vegetable crops.  Be careful about the kind of organic material you use.  Hay can introduce a considerable load of weed seeds into your garden. 

Black plastic mulch is of specific benefit to certain vegetables including tomatoes, eggplants, peppers and vine crops.  In addition to shading out and eliminating weeds, plastic mulches conserve moisture and promote early crop growth by helping to heat up the soil in spring.  Landscape fabric has the added advantage of being water permeable and can be used for multiple years; although it is more expensive than black plastic. 

Most importantly, do everything possible to keep garden weeds from going to seed.  One red root pigweed plant can produce 100,000 seeds that can continue to germinate over the next 15 to 20 years. 

Protecting Pollinators

      Spring is here.  Don’t blink; it will be summer soon enough.  As the dandelions, violets, and Bradford pears bloom, we need to think about all the insects, including honeybees, that pollinate those flowers.

Hover Fly pollinating a flower

Insects pollinate a large percentage of food crops grown in the U.S. and all over the world.  Many different species of pollinators exist, but the insect best equipped for this job is the honey bee. Honey bees are exceptionally efficient at collecting and transferring pollen among the flowers of a particular crop.  In a practice known as “flower fidelity” groups of foraging bees will visit just one type of flower, collecting and storing pollen in baskets located on their legs.  As the bees fly from flower to flower, pollen particles are transformed between male and female parts triggering the plant’s reproduction cycle which results in a fruit or vegetable that may eventually find its way to a dinner table. 

A growing concern for U.S. agricultural producers is the continuing decline of honey bee populations.  According to the National Agricultural Statistics Service, the number of colonies in Kentucky has dropped dramatically over the last century from 152,900 in 1909 to just 5,000 in 2009.

Many studies are underway to try to pinpoint the cause for this decline, and so far several factors have emerged as detrimental to honey bee health.  One of these involves the use of pesticides and insecticides which can produce harmful effects in other pollinators, too.

Approximately 4,000 species of native or wild bees assist the honey bee in making a large contribution to the pollination task.  They include everything from large bumblebees to tiny sweat bees.  There are miner bees, carpenter bees, mason bees, plaster bees and orchard bees -- all named for the types of nests they build.  Butterflies and some flies also pollinate certain plants. 

You can help promote and protect insect pollinators by following a few simple rules.  Never spray plants with insecticides when the plants are actively blooming.  If chemical applications are necessary, strive for infrequent use and choose selective products with minimal impact on natural resources, especially bees. 

Promote pollinators and invite them into your environment by planting a diverse landscape with flowers, trees and other greenery that bloom in succession from spring into fall. 

Pest Management Tips for Home Vegetable Gardens

Now is a good time to start thinking about pest control for your home vegetable garden.

You can control pest problems, and perhaps prevent future difficulties, in your garden by doing some advance planning and following a few simple Integrated Pest Management practices. IPM promotes minimal pesticide use and emphasizes use of all available pest control methods including cultural, mechanical and biological practices to prevent pest problems.

Examples of the IPM approach include using plants with natural disease tolerance or resistance, using mulch to control weeds or row covers to prevent insect damage and using naturally occurring organisms such as lady beetles or praying mantis. 

Sanitation is another good IPM practice. Keep your garden well-groomed during active growth. Once you spot diseased plant material, remove it immediately to keep diseases from spreading. Also, promptly remove vegetable plants when they cease to be productive. Although you should clear out unproductive vegetable plants from the garden area, you can add this plant material to a compost pile.

Before you buy seeds, plants or fertilizer, start your garden off right by answering these questions.

Have you taken a soil sample to determine if soil fertility and acidity/alkalinity will meet plants’ nutrient requirements?

Soil test results will let you know how much fertilizer is required to provide plants with needed nutrients, while preventing excessive use that contributes to groundwater, stream and lake pollution. Plants that are stressed or weak from insufficient nutrients or a pH that’s too low or too high are more susceptible to disease and can’t readily tolerate insect damage. To give your plants a healthy start, soil test and apply the fertilizer and other amendments according to the recommendations.

Do you plant your garden crops in the same spot year after year?

Crop rotation can help prevent insect and disease build-ups. For example, potatoes, eggplant, tomatoes and peppers are subject to the same insect and disease problems. Therefore, none of these crops should be planted in the same location more than every three consecutive years. After three years, switch to a different crop like beans or corn. If you have limited garden space, plant some vegetable plants in containers such as large pots or half whisky barrels as a form of crop rotation.

Make a diagram of your garden each year to avoid planting the same or closely related crops in exactly the same spot too frequently.

How do you select a vegetable plant variety?

Whether you are planting corn or tomatoes, check to see that the variety you are planting has some disease resistance or tolerance. For example, select tomato varieties labeled “VFN,” as they’re resistant to Verticillium Wilt, Fusarium and root-knot nematodes. Whereas, a tomato variety leveled “V” is only resistant to Verticillium Wilt.

Do you buy the cheapest transplants?

When it comes to transplants, the best buys are the healthy ones. A healthy transplant was seeded at the right time, grown at the proper temperature and received adequate light and moisture. It will have a compact growth structure with very small distances between leaves. The leaves will be dark green, large and upright with no tendency to droop. Stems will be pencil thick and rigid.

Avoid transplants that are beginning to produce flowers or fruit. It might seem that buying a plant with blooms or fruit will give you a head start in the garden. However, plants trying to produce fruit or flowers are slow to develop the good root systems needed to support later fruit production.  Never buy plants that have insects present or are showing disease symptoms.

Do you plan to use mulch in your garden?

Mulch helps prevent weeds that will decrease your garden’s production by competing with the vegetable plants for water, nutrients and sunlight. In addition, some weeds harbor diseases and insects that attack vegetable plants.  Mulch also helps conserve soil moisture.

Several types of commercial mulch are available, or you can use newspapers for the mulch. Start with five to eight layers, adding more layers as the newspapers decompose to prevent weed growth throughout the growing season.  Be sure to use only newspapers printed with soy-based ink and avoid using the glossy inserts.

If you have other gardening questions visit www.extension.org or contact the Hardin County Cooperative Extension Service at 270- 765-4121. 

For more information on growing vegetables, request our publication, “Home Vegetable Gardening in Kentucky” (ID-128). It is available from your local Extension Service office, or from the UK Web site at http://www.ca.uky.edu/agc/pubs/id/id128/id128.htm.

Educational programs of the Cooperative Extension Service serve all people regardless of race, color, age, sex, religion, disability or national origin.

NOTE:  The Lincoln Trail Master Gardeners are at the Extension Office EVERY AFTERNOON to answer your gardening questions.  Please call 270.765.4121 to consult with a Kentucky Master Gardener about any gardening questions.

Gardeners’ Tool Box Series:

How Will My Plant Die? - April 19, 2011

Everything dies at some point.  But not every plant has to die an untimely death.  Learn what you can do as plant-parents to keep your children out of harm’s way.  Nutrition, care of the newly planted, and raising the green teenager will set you on the path to long-lived plants. Registration ($7) and payment must be received by April 15. Class is held at the Hardin County Extension Office beginning at 6:30 p.m. 

Spring Flower Arranging - May 3, 2011

Back by popular demand!  Assemble a  small springtime flower arrangement.  The perfect gift for Mothers’ Day or give the class as a gift.  All the supplies for the arrangement will be included in the class fee. Registration ($10) and payment must be received by April 22. Class is held at the Hardin County Extension Office beginning at 6:30 p.m. 

Don’t Forget about the Lincoln Trail Area Master Gardeners’ 13^th Annual Plant Fair: MAY 21^st from 9 a.m. – 3 p.m. at the Hardin County Extension Office, 201 Peterson Drive, Elizabethtown.