April Gardening Tasks

Raymond "Ray" Dempster
March 25, 2008
þStocks of Local Interest
March 27, 2008
Raymond "Ray" Dempster
March 25, 2008
þStocks of Local Interest
March 27, 2008

April is the month that most outdoor plants growing in your landscape should be in full swing. It is also the month that you can fertilize your lawn! Many of you have been waiting patiently to do this and I commend you for waiting. You will have less disease and insect problems in your lawn by waiting until now to fertilize.

April is your last chance to apply dormant oils on your outdoor plants to control scale insects. Use the oils on camellia, hollies, variegated privet, magnolias and gardenias. Oil sprays are safe only when the temperature is below 85 degrees. So, if you miss April, you’ll have to wait until late October or early November to apply them. Horticultural oils or summer oils are safer to use during the time of year when warm weather prevails.

April is the time to prepare hanging baskets. Many plants grow well and look good in baskets, but ferns are probably the most highly prized. They come in a variety of shapes and sizes and are especially attractive in these hanging planters.

In April you may plant annual bedding plants as soon as the frost danger has passed. However, you could start your seeds indoors earlier in the month for earlier blooms. New varieties of lantana and verbena would be excellent perennial additions to your landscape. In April you should make cuttings of plants kept inside over the winter, such as begonias, sultana and coleus.

Divide your old, large clumps of chrysanthemums at this time. If you don’t, you may end up with weak, spindly growth that has only a few flowers. During April you can prune spring flowering shrubs such as spirea, flowering quince, azalea, jasmine and forsythia after they have bloomed. This is a good time to fertilize shrubs, too.

If you want healthy roses this year you should plan a regular preventive spray schedule at 7- to 10-day intervals. It’s best to spray roses with a fungicide before disease organisms attack, especially blackspot — then keep a protective covering of a fungicide on the plants at all times throughout the season. Select old garden, Knockout or antique roses if you want to minimize maintenance.

If you’re a person who is more interested in growing things that are more edible than ornamental, here are some suggestions for your vegetable garden. In April you can plant snap beans, lima beans – sometimes called butter beans – collards, cucumbers, eggplants, cantaloupes, okra, southern peas, pepper transplants, peanuts, pumpkin, winter squash, summer squash, sweet corn, sweet potatoes, tomatoes and watermelon.

Vegetable gardens are also seeing some disease activity. I have seen Early Blight on Irish potatoes and this disease will also impact your tomato plants. Early Blight is a fungal disease that causes a “target shaped” brown spot pattern on the leaves and stems. These spots average about 1/2 to one inch in diameter, are irregular and may take on a concentric ring or “bull’s eye” pattern. Preventative spray programs using a fungicide containing chlorothalonil should be used to minimize this fungal disease.

Time to Plant Warm Season Bedding Plants

Now is an ideal time to set out warm season annual bedding plants in our area. Bedding plants are flowering herbaceous plants used to provide instant color to an established landscape. They also can be used for early color while you’re waiting for more permanent woody shrubs and trees to develop.

Many gardeners use annual bedding plants extensively and others plant only a few small areas each year or use some in container and patio planters. Bedding plants are best displayed in masses or along edges of landscape beds. You to consider these tips when you’re designing and planting a landscape area using bedding plants:

-Use masses of the same flower color to maximize visual impact.

-Use colors that contrast pleasantly with the background.

-Use color combinations that blend well.

-Locate color where you want to draw the visitor’s eye.

You should also consider final plant height and spread when planning the design. Shorter or dwarf plants need to be used for edging or in a bed foreground, with medium plants placed in bed centers and taller plants in background areas.

Proper soil preparation is the most critical step in establishing a successful planting. Be sure to prepare raised beds to allow for improved drainage. In Louisiana, inadequate drainage from bed areas is responsible for most plant problems.

Native soil should be amended with organic matter, such as peat moss, pine bark or compost. If you have a heavy clay soil, adding sand is recommended.

Incorporating a slow-release complete fertilizer into the bed before planting or broadcasting the fertilizer after planting is excellent for providing valuable nutrients for several months. After planting, mulching flowerbeds will result in moisture conservation and weed suppression, while enhancing appearance. Pine straw is excellent mulch for this purpose.

You should water plants thoroughly after planting, but be careful not to over water.

Watering is the most critical task in maintenance of plant material. Beds should be

watered only as needed, when soil begins to dry and plants start to show slight signs of drought stress (afternoon wilting or drooping lower leaves).

You can harden plants by watering less frequently and thoroughly instead of often and

shallowly. You should water only the soil, not the foliage. Frequent overhead watering

damages blossoms and increases disease.

During the season, remove spent blossoms on bedding plants to prevent seed formation.

This process allows the plant to continue to use energy to produce blooms. If plants become overgrown during the season, shear back to promote renewal of a bushy growth habit. Such a shearing may be needed with impatiens.

When bedding plants reach the end of their life cycle or season, remove and replace them with other annuals. Some examples of excellent warm-season annual bedding plants for our area include ageratum, begonia, celosia (cockscomb), coleus, impatiens, petunias, salvia, marigold, gomphrena, zinnia and periwinkle (vinca).

For more information on these and other horticultural topics, please call me at 985-446-1316, email me at bhfletcher@agctr.lsu.edu or visit the LSU AgCenter web site at www.lsuagcenter.com.