Garden Column for the Salisbury Post

Darrell Blackwelder

November 14, 2003

    Those that reseeded lawns this fall have enjoyed optimum growing conditions over the past few months. Warm weather and ample rain have allowed cool season fescue lawns to germinate and becoming well established this fall. However, this unseasonable weather pattern also provided winter weeds the perfect opportunity to germinate early making our lawns look less than stellar. The brief cool weather Rowan County experienced a month ago was just cold enough to initiate winter weed germination.

     Winter annuals such as chickweed, henbit and annual bluegrass need cool soil temperatures below 55 degrees to break seed dormancy and germinate. Chickweed is one of them most aggressive lawn weeds observed this fall. Normally, this weed germinates during cooler weather and does not actively grow until warmer temperatures arrive in late February or early March. Mother Nature has tricked the weeds and they are growing like its April. The arrival of cooler weather this weekend will certainly slow their growth, but will not kill the weeds. The weeds will remain somewhat stunted until warmer weather arrives again in the spring. Not only are the weeds unattractive, but also their competition stunts and retards the growth of newly seeded lawns.

    Winter broad-leafed weeds such as chickweed, henbit and wild garlic (wild onions) can be controlled with post emergence herbicides such as Weed B Gon or Trimc. These herbicides are blended for broad-spectrum weed control. However, it is very important for those with newly seeded lawns wait until the lawn is well established before applying broad-leafed herbicides. A well established lawn is best defined as newly seeded turf that has been mowed at least three or four times. Applying to young turf may damage, stunt or even kill new and emerging seedlings. Wait until early spring to kill the weeds if you have any doubt as to the condition of newly seeded turf. Those that still need to reseed thin or bare areas missed during early plantings should probably wait until early spring. Apply herbicides to broadleaf weeds in the early spring before the rapid flush of growth.

    Aggressive winter weeds such as chickweed are extremely difficult to kill they are blooming. Pre-mixed herbicides with hose applicators work well to control broad-leafed weeds. This type of herbicide eliminates measuring, mixing and the problem of storing unused pesticides. Buy only the amount needed for one application. Premixed herbicides will have the area coverage on the label.

Darrell Blackwelder is an agricultural agent in charge of horticulture with the North Carolina Cooperative Extension Service in Rowan County. For archived garden columns or other information, visit the Rowan County Master Gardener web site at www.rowanmastergardener.com , e-mail Darrell_Blackwelder@ncsu.edu or phone at 704-633-0571.