Pigweed

By Barbara Pleasant, June 23, 2008

Pigweed (Amaranthus retroflexus) is often called redroot pigweed because of its pinkish red root. A warm-weather annual most common where summers are hot, pigweed seeds sprout in late spring or early summer. Several common garden insect pests eat pigweed, so some gardeners allow a few plants to remain among vegetables, and then pull them out before they develop seeds. If your garden has too much pigweed, use a sharp hoe to cultivate infested soil when the plants are young, or spray them with an organic herbicide containing acetic acid or clove oil. Pull older plants when the soil is moist.

Weed Control Techniques

Cultivating. Slicing and dicing weeds with a hoe works best when the soil is relatively dry, and the same goes for cultivating with a tiller. With their tops mangled and roots cut, most young weeds will quickly shrivel up and die. Be careful to cultivate only the top inch or two of soil or you may injure nearby garden plant roots and drag new weed seeds to the surface. A sharp hoe works much better than a dull one, so refresh the edge on your hoe with a steel file between weeding sessions. After using either a hoe or tiller to cultivate weeds, go back the next day to nip out any survivors. When battling perennial weeds, you can weaken the plants by chopping them down with a sharp hoe, but it's best to combine hoeing with digging to achieve good control. Never use a tiller in soil that is infested with bindweed, quackgrass, or other weeds that regrow from small pieces of root; they are easily spread by rototilling.

Organic herbicides. There are several herbicides made from natural ingredients. Those that contain clove oil (eugenol) give the best control of young broadleaf weeds. Products containing acetic acid, often in combination with citric acid, do a good job on young grasses. Some products contain both clove oil and acetic acid, so they are useful for a broad variety of weeds. Soap-based herbicides dehydrate leaves by cutting through their protective layer of cutin. All of these types of organic herbicides work best on young weeds and pose only a temporary setback to well-rooted perennial weeds. To minimize damage to neighboring plants, spray only in dry, still weather. To maximize effectiveness, spray young weeds when temperatures are above 70 degrees F and the sun is shining brightly. Be aware that repeated applications of a product containing acetic acid (which is very strong vinegar) can lower the soil's pH, making it more acidic.

Pulling. Most young weeds can be pulled from the soil. They will slide out most easily if you pull them when the soil is wet. Getting the root up is crucial, so think of the main stem as the root's handle, and grasp it as close to the soil line as you can. If you find that the weeds are breaking off at the crown as you pull, slip a kitchen fork, dandelion weeder, or similar tool under the weed, and pry and twist as you pull it up. Weeds that have taproots, such as dandelion and plantain, usually must be pried out. A flexible pair of waterproof gloves will keep your hands comfortable as you weed, and it's good to have a nice sitting pad, too. Let pulled weeds bake in the sun for a day or so before composting them. If pulled weeds are holding mature seeds, compost them separately in a hot, moist pile before using this compost in the garden.

Image courtesy of Plant Stock Photos

Other Broadleaf Weeds
Black Medic
Weed info for Black Medic
Broadleaf Plantain
Weed info for Broadleaf Plantain
Buckhorn Plantain
Weed info for Buckhorn Plantain
Buttonweed
Weed info for Buttonweed
Canada Thistle
Weed info for Canada Thistle
Carpetweed
Weed info for Carpetweed
Chickweed
Weed info for Chickweed
Cinquefoil
Weed info for Cinquefoil
Corn Speedwell
Weed info for Corn Speedwell
Curly Dock
Weed info for Curly Dock
Dandelion
Weed info for Dandelion
English Daisy
Weed info for English Daisy
Ground Ivy
Weed info for Ground Ivy
Hawkweed
Weed info for Hawkweed
Henbit
Weed info for Henbit
Hop Clover
Weed info for Hop Clover
Horsetail
Weed info for Horsetail
Indian Mockstrawberry
Weed info for Indian Mockstrawberry
Lambsquarters
Weed info for Lambsquarters
Mallow
Weed info for Mallow
Pigweed
Weed info for Pigweed
Prickly Lettuce
Weed info for Prickly Lettuce
Prostrate Knotweed
Weed info for Prostrate Knotweed
Purslane
Weed info for Purslane
Ragweed
Weed info for Ragweed
Shepherd's Purse
Weed info for Shepherd's Purse
Smartweed
Weed info for Smartweed
Sorrel
Weed info for Sorrel
White Clover
Weed info for White Clover
Wild Garlic
Weed info for Wild Garlic
Wild Violets
Weed info for Wild Violets
Woodsorrel
Weed info for Woodsorrel
Yarrow
Weed info for Yarrow

« Return to the Weeds Library Home Page

 

Today's site banner is by mcash70 and is called "Aztec Headdress Daylily"