Least-Toxic Control of Chickweed Choose a different pests


Pest type: Plants

In-depth information:

The most abundant species of chickweed are called common (Stellaria media) and sticky (Cerastium glomeratum). These species are both winter annuals that like to grow in gardens, lawns and agricultural areas. Common chickweed loves to grow in moist areas, but sticy chickweed can grow easily in dry sites. Common chickweed can harbor insect bests and plant viruses.

You can identify common chickweed because it can form dense mats, and is usually stretched out flat on the ground. When growing in a lawn, it usually does not grow above 2 inches. If it is growing in a garden or in shady conditions, it can grow up to 6 inches and is less compact. The leaves will usually have pointed tips, and the plant will have five white flower petals (although due to the dividing point, it will look like it has ten petals).

Sticky chickweed looks similar to common chickweed but grows in a more upright position. The leaves as well as stem are hairy, which can make the plant look gray.  Some of the hairs have glandular secretions and give the plant a sticky feel.

Is it a problem?

According to UC IPM:

When growing without competition from other plants, common chickweed can produce approximately 800 seeds and it takes 7 to 8 years for the seed bank (supply of viable seeds in soil) to be 95% depleted, ensuring an infestation for many years. Because of its ability to produce large numbers of seeds under cool temperatures, common chickweed rapidly colonizes any cool, moist area before winter or spring crops can become competitive. In commercial situations common chickweed can limit winter vegetable production by competing for space, light, and nitrogen. Additionally, common chickweed can serve as a host for insect pests such as lygus bugs and thrips as well as a reservoir host for tomato spotted wilt virus (TSWV) and cucumber mosaic virus (CMV).

In turf and landscape plantings, common and sticky chickweed can be unsightly, reducing the aesthetic value. In cool, wet conditions common chickweed forms a dense mat of spreading stems that may root at the nodes. This increases the difficulty of hand weeding or hoeing.

Pest prevention practices

Remove potential habitat
Foster natural resilience

In-depth information:
Having healthy soil, using at least two native turfgrasses, proper watering, and a sensible landscape design can all help your lawn ecosystem develop a natural resistance to weeds. Indeed, chickweed and other weeds in your lawns are often a sign that the balance of your soils are off. Shallow watering or drought, poor drainage, low mowing height and low light tend to promote chickweed growth, so using proper watering techniques, mowing the lawn above 2 inches, and cultivating a space with more light can help you manage weeds in your lawn.

Monitoring and record-keeping

You can control chickweed before it flowers, although this can be difficult  because the period between germination and flower production is short. As long as you monitor regularly and remove plants as soon as you see them, you can prevent seeds from developing and accumulating in the soil. It is also important to note that you must remove chickweed from the site due to it's ability to reroot from stem-nodes in moist conditions.

Non-chemical and mechanical controls

Mow lawn above 2 inches
Proper watering
Remove debris and habitat
Handpick and destroy

In-depth information:
According to UC IPM:

Cultivation, including hand weeding, will effectively control chickweed if done early. It is most effective if the soil is dry and plants are small. Cultivation when plants are large and soil is moist can lead to spread of the weed through re-rooting. Under this situation, the weeded debris should be removed. Chickweed germination decreases with depth of the seed. Turning the soil over can reduce seed germination, but may also bring other weed seeds closer to the surface. Monitor the soil surface for chickweed seedlings throughout late fall and winter and then remove them by shallow cultivation or by hand pulling.

Solarization using clear plastic mulch is a method of heating the soil to temperatures lethal to seeds and other pests. It is an effective method for controlling many annual weeds including chickweed. If solarization is done in late summer and the soil is not disturbed, subsequent winter crops can develop a canopy and become more competitive before other winter weeds germinate.

Using an organic mulch such as wood chips, at least two inches deep, will reduce the amount of weed seeds germinating by limiting light and serving as a physical barrier. Synthetic mulches such as landscape fabrics may also be used. In landscaped areas, they should be covered with an additional layer of mulch (rock or bark) to reduce deterioration of the fabric by UV radiation. Vegetable gardens also can utilize black plastic, both as mulch into which seeds or transplants are placed and also between rows.

In turf, the primary method of control is to maintain a thick vigorous lawn. This will prevent chickweed seedlings from getting established. Deep, infrequent irrigation also discourages chickweed infestations. Follow fertilization guidelines as recommended for a particular turf species and avoid over-application of nitrogen.

Biological controls

Goats are herbivorous foragers that are very effective at controlling weeds since grass is their least desirable food choice. They can be especially effective for roadside management, along railroad tracks, parks, forests, etc. Many people now make a living by contracting themselves and their herd out for weed control around the nation.

Least-toxic chemical options as a last resort

  • Horticultural vinegar, or acetic acid, is also effective at killing certain weeds. Avoid spraying other green vegetation, such as turfgrass, since this is a nonselective plant killer.
  •  Herbicidal soaps are highly refined soaps that can penetrate the waxy coating on plant leaves, causing them to dry out.

Acetic Acid (Vinegar)

Chemicals to Avoid

Look at your product labels and try to avoid products containing those chemicals listed below:

(A = acute health effects, C = chronic health effects, SW = surface water contaminant, GW = ground water contaminant, W = wildlife poison, B = bee poison, LT = long-range transport)

Dicamba (A, C, GW, W)

dithiopyr (SW-URBAN, GW, W, B)

Glufosinate ammonium (C, SW, W)

Glyphosate (C, SW-URBAN, W)

Oryzalin (C, W)

Triclopyr (GW, W)