information about bindweed Learn how kudzu took hold in the U.S. and how to identify and control an outbreak if it invades your landscape. – Preen Green Thumb – What’s That Weed? As a small child I got a kick out of picking dandelions just to blow away the fluff. Now I pluck them from the lawn in slow motion. Dandelions have a bad rap
Field Bindweed · Convolvulus arvensis L. · is a perennial broad-leaved plant that spreads over the soil and other structures, and often form mats. Leaves alternate along the stem. Leaf size and shape will be varied; typically leaves are up to two inches long and egg-shaped. Flowers are typically white, but often they are light pink and have two leaf-like structures half-way between the main stem and the base of the flower, which is a distinct characteristic.The flowering stage is when most field bindweed is noticed.
The root system is what makes the weed so hard to control. Roots can extend to as far as 30 feet deep. These roots compete with crops for moisture and nutrients, and give field bindweed an advantage over the newly seeded crops by already being in the soil.
Seed pods are egg-shaped, 1/4″ in diameter, and contain two to four seeds. Seeds are shaped like a slice out of an orange, small (only 1/8″ long), and covered by rough raised dots. Though small, these seeds can lay dormant for as long as 30 years.
Field Bindweed is a noxious weed that can be a severe problem in the largest field or the smallest garden. A summer herbicide treatment will control existing growth and eliminate seed production. For lasting control, a three-phase treatment plan should begin at first blooming and continue through fall:
Phase I Treat Field Bindweed with an approved herbicide or control measure shortly after flowering blooms appear. Phase II Retreat new bindweed growth approximately 30 to 45 days after the initial treatment or when 12″ – 18″ runners exist. Phase III Retreat returned bindweed growth with an approved systemic herbicide after the first frost in the fall, but before nighttime temperatures reach 20°F. Chemical Controls
Weed With Long Seed Pods
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The “Weed that Ate the South” Is Heading North
Kudzu can be identified by its lobed leaves that grow in three-leaf clusters. When flowering, it produces reddish-purple flower spikes which mature into flat, brown, 2-inch-long seed pods. iStock / Getty Images Plus
Kudzu – that vining weed that earned the nickname the “vine that ate the South” for its vigorous spread in warm-weather states – is expanding into new areas. Warming temperatures and the weed’s prolific ability to spread has increased kudzu’s range to Ohio, Pennsylvania, Michigan, and New York, including as far north as the Canadian shore of Lake Erie. It’s also spread westward from Mississippi and Alabama into Texas.
Few plants have the incredible growth power of kudzu (Pueraria). Under ideal growing conditions, it can grow nearly a foot a day and 60 to 100 feet in a season. The plant sends down large tap roots, its crowns can send up as many as 30 vining shoots, and its leaves have the ability to mine growth-enhancing nitrogen directly from the air. Kudzu spreads by seed but mainly by rooting where its stems touch the ground.
Kudzu is an invasive vine that grows fast and covers everything, eventually killing many native species. iStock / Getty Images Plus
Kudzu first came to the United States from eastern Asia as a promising specimen at the U.S. Centennial Exposition in Philadelphia in 1876. It was introduced in the South seven years later at the New Orleans Exposition. The plant quickly caught on for several of its redeeming qualities. Cattle farmers used the high-protein, fast-growing leaves and stems as livestock feed. The Civilian Conservation Corps and others planted it widely in the first half of the 20 th century for erosion control. And southern-states home gardeners bought kudzu as an ornamental vine that quickly shaded porches. Besides the dense habit of the green foliage, kudzu produces attractive arching spikes of purple flowers in late summer.
By the 1950s, ecologists realized that kudzu was doing too well for its own good. It was choking out native vegetation, overspreading and killing even tall trees, and pulling down power lines. The U.S. Department of Agriculture reclassified kudzu as a weed in 1970, and efforts since have been to slow or eliminate it instead of plant it.
Kudzu can be identified by its lobed leaves that grow in three-leaf clusters and have tiny hairs on their undersides. The reddish-purple flower spikes mature into flat, brown, 2-inch-long seed pods.
An outbreak of kudzu is best stopped by digging out all rooted pieces when the plant is young. Repeated cutting or mowing to the ground also can weaken an existing stand of it. Several spray herbicides are effective at killing kudzu, although repeated applications over several years might be needed to get rid of it completely.
Green Thumb – What’s That Weed?
As a small child I got a kick out of picking dandelions just to blow away the fluff. Now I pluck them from the lawn in slow motion. Dandelions have a bad rap because they spread so easily, but it’s important to know that their early flowers are a food source for hungry bees emerging from the hive. That fact changed my opinion of dandelions.
Most weeds don’t scream for attention like dandelions. Nevertheless, some have interesting characteristics. Here are the names and descriptions of some you might find in your yard. Most are notorious for their seed production.
Cleavers (Galium aparine) has colorful common names like “Sticky Willie”, “Hitchhikers”, and “Velcro Plant”. It grows fast in gardens, forests and fields. The long, lanky stems crawl along the ground and over other plants, with this interesting feature: fine hook-like hairs on the stems and leaves stick to you like, well, velcro. The plants are hard to pull out because the stems break off easily. This weed is oddly attractive, but you don’t want any plant around that produces 300-400 seeds. Even the tiny white flowers produce burrs tough enough to pass through the digestive tract of animals.
Hairy Bittercress (Cardamine hirsuta) is an inconspicuous spring-loaded thing that waits to be touched. Then it shoots its seeds out forcefully 10 feet or more. It is small but mighty. The plant is a winter annual which means its seeds germinate in the fall and develop into small rosettes that overwinter. In early spring they send up three to eight inch long stalks of small white flowers that produce slender seed pods. An average plant will produce 600 seeds. This one is also a summer annual.
Pineapple Weed (Matricaria discoidea) gets its name from the pineapple/camomile scent it produces when crushed. A native of northeast Asia, it’s an annual that grows in sunny gravel or compacted soils. Its taproot allows it to survive a harsh location. The flower is a yellow-green cone at the tip of a stem. The plant can grow up to 12 inches tall and looks like a miniature bush with fern-like leaves.
Creeping Spurge (Euphorbia supina) forms a flat mat. I’ve seen them the size of a dinner plate. It’s an annual that often has purple mottling on its leaves. When broken it drips a poisonous, white sap that can irritate the skin and eyes. Wear gloves and pull it out by the tap root. It thrives in full sun and drier soils. In the summer you’ll see it growing from cracks in sidewalks where it stretches out over the hot surface. It would make a dense groundcover, but for one serious flaw. A single plant can produce thousands of seeds.
Common Yellow Woodsorrel (Oxalis stricata) is a common weed that tolerates a wide range of conditions and can grow 6-15 inches tall. It is also called “Sheep’s Clover” because its leaves are similar to clover. The half-inch yellow flowers are followed by erect seed pods that open explosively when touched. It can also form colonies from underground rhizomes. This weed is best controlled by mulching and hand weeding.
Garlic Mustard (Alliaria petiolata) is a highly invasive biennial that smells like garlic when crushed. This plant is a menace because it is allelopathic which means it produces chemicals that inhibit the growth of other plants. The first year’s growth is a small rosette. The second year it shoots up a one to four foot stem that develops flowers. Put on your gloves and pull this out whenever you see it. Don’t leave a flowering plant on the ground because it can set seeds. A big plant can produce thousands.
It’s always best to pull out weeds before they flower. Mother Nature has tricks up her sleeve.
Janice M. Weber – University of Illinois Extension, DeKalb County Master Gardener
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