Lawn Care Tips and Weed Control

The two most serious winter annuals are chickweed and henbit, but others that sometimes appear include dead nettle, sheperds purse, peppergrass, wild mustard and yellow rocket". Seeds of these winter annuals often begin growth in September and continue germination throughout the fall or early spring as conditions permit. In the fall the small seedlings often remain unnoticed. As good growing conditions improve in early spring, these small plants develop rapidly. It is at this time that they become evident and may crowd out weakend existing lawn grass.

By May the mature plant begins drying, leaving a seed crop to germinate in the fall. Common chickweed is a low growing plant with creeping stems. The small leaves are opposite on these stems, oval-shaped and smooth. Small star-like white flowers are produced abundantly. The plants form dense clumps where the lawn is thin. Henbit grows taller than chickweed, and has squarish stems. In early spring it produces abundant lavender flowers. It also weakens and dies in late spring. Where it is not cut, it can grow tall enough to sprawl over other plants and weaken them.

Leaves are opposite on the stems, hairy, and oval shaped with rounded teeth along the margins. Dead nettle, a close relative, has similar flowers and growth, but the leaves are pointed at the tips and spaced more closely along the stems. The other winter annuals are loss invasive, but plants such as sheperds purse, peppergrass and yellow rocket may form rosettes of leaves close to the soil surface.

Most winter annuals are fairly difficult to kill in late spring, after they are well developed. However, since they grow from seeds in the fall, pre-emergence herbicides can control them if applied in the fall. These are the same type of herbicides used to kill crabgrass when applied in the spring.

Since winter annuals begin germination in early September, prompt application of one of these materials can greatly reduce these nuisance weeds in the lawn next spring. Several materials can provide control, among them Dacthal and Betasan. Check lawn herbicide labels in nurseries and garden centers to see which materials available provide pre-emergence control for these weeds.

Since fall is also a time to fertilize lawns, some combination fertilizer and herbicide materials may also be used. Lawns which are seeded in the fall cannot be treated with most pre-emergence herbicides. However, pre-emergence weed control in a newly seeded lawn is possible with Siduron. It is not as commonly available in many areas as other-herbicides, but may be found under trade names such as Tupersan and Trey.

Mac Perry's Florida Lawn and Garden Care by Mac Perry.