Common Weed Characteristics
Plants often reproduce in different ways: rhizomes, cuttings, runnersThey produce many seeds, usually tiny seeds, that have burrs, float, or disperse easilyIf you pull some weeds out, they might break off and re-sproutWeed can usually live in many environments, soils, and conditionsThey grow fastSeeds can remain dormant for many years and can self-pollinate
Poisonous or extremely invasive weeds are best removed, while other weeds may be more welcome around your home. Use this list to identify 35 common weeds plus their potential pros and cons. As is often the case with toxic plants, poison sumac can also be very attractive; its white berries and bright fall foliage make pretty, albeit potentially dangerous, yard accents. How to control it: No matter what method is used, it might take more than one attempt to achieve complete success—and you might find yourself using several different ways. You can dig and pull, smother, or use herbicide. Whichever method you choose, wear long sleeves, boots, protective eyewear, and gloves whenever you are in an area where poison sumac is suspected. How to control it: Knot weed requires a multi-pronged approach, such as constant mowing and herbicide application in spring or early summer and retreatment in early fall. How to control it: Use a pre-emergent herbicide to keep seeds from sprouting. To kill crabgrass, remove the plants by hand, roots, and all. If that doesn’t work, use a post-emergent herbicide. Also, use an organic fertilizer to encourage the growth of lawn grass, which will crowd out the crabgrass. How to control it: Keeping dandelion seeds from germinating won’t be enough to eliminate the plants. You can use herbicide to eliminate your dandelions, but the most effective and least harmful approach is to dig the flowers up from the roots. How to control it: Pull or dig up plantain weeds. Keep pulling them up before they can produce seeds. Eventually, the plant will give up. It may seem like a continuous process, but persistence is key. How to control it: Ragweed can’t tolerate constant mowing or rich soils. Maintain a healthy, mowed lawn in its place on a regular feeding schedule to keep ragweed at bay. How to control it: Giant ragweed seeds can produce up to 5,000 seeds per plant, dispersing via the wind. Its seeds can also live 10 years in the soil. This plant is a crop killer. To keep it at bay, keep lawns healthy. Healthy grasses can keep giant ragweed from taking over. Tilling stands of seedlings can also disrupt their life cycle. If herbicide is necessary, employ a pre-emergent herbicide in the spring (Atrazine). How to control it: Effective control requires prevention of seed production, deep tillage of the root system, and pulling out plants. Also, apply herbicides or landscape fabric on top of it to smother it. It needs light to grow, although it can remain dormant for up to five years. How to control it: If you have a small area, dig and pull to remove this weed. It may be somewhat ineffective since stems or roots left behind can continue to grow and spread. Being persistent can lead to successful eradication. However, you can also rely on broadleaf herbicides applied in late September, then again a month later. How to control it: Purslane can be controlled well by hand pulling if you do it when the plant is young and before it goes to seed. If it’s seeded itself, you can also use post-emergent broadleaf herbicide on young plants to eradicate it. How to control it: This plant is best managed by hand pulling. Wear gloves to protect your hands from the stinging hairs on the plant stems. Also, perform close mowing to prevent the plant from developing its fruit. You’ll be able to identify curly dock by its greenish blossoms that cluster in long thin flower stalks at the top of the plant. After the flowers have dried and turned brown, they remain in place, making the plant easy to recognize. Be aware that curly dock is toxic. How to control it: You can control curly dock by tilling and uprooting this plant. Mowing will prevent seed production and reduce top growth. If it becomes problematic, apply a post-emergent herbicide in the fall. You can also apply herbicides in the spring. How to control it: Keep bedstraw plants from flowering, setting, and spreading seed. Mow Galium mollugo before it sets seeds to prevent its spread and give grasses a chance to outcompete the plant. Till and rotate the soil to kill perennial crowns and new seedlings. How to control it: Clovers are relatively easy to manage in the home garden by hand-pulling, cultivation, and mulch application. In large, landscaped areas, herbicides may also be necessary. Clover seeds have a hard seed coat that is heat tolerant; composting and solarization do not kill the seed. It can survive many years in the soil, sometimes making eradication difficult. How to control it: Spotted jewelweed has a shallow root system and should be hand-pulled whole, which is easier done when the soil is damp. If the plants do not have seed capsules, they can be composted; if they have seeds, bag and dispose of them. How to control it: The most effective method is to pull out bittersweet vines and roots whole; the roots appear long, intestine-like, and orange. You can also cut it down as close to the soil level as possible and use herbicide on the fresh stem cuts to eradicate the vines. Equisetum hyemale, by contrast, is a more useful horsetail plant to the landscaper. It is an architectural plant that can be employed as an accent around water features. If given moist soil, it will spread, so consider potting it up for use around water features so that you’ll have firm control over it. How to control it: Conventional methods like pulling, tilling, smothering, or herbicide are ineffective for removal. The best way to get rid of horsetail weed is to change the soil conditions drastically by improving the drainage, raising the pH, and increasing the soil’s fertility. How to control it: Chickweed is easy to control by hand-pulling if done early before it flowers, usually by late fall and winter. Also, use a layer of organic mulch wood chips or landscape fabric to prevent seeds from germinating or having the light they need to grow. You can also use a pre-emergent herbicide in early spring. How to control it: Canadian thistle isn’t easy to control because its extensive deep root system helps it to rebound easily. Its horizontal roots may extend 15 feet, and its vertical roots may go up to 15 feet deep. This weed’s seeds remain viable for up to four years in the soil. When first spotted, remove it by hoe before it becomes well-rooted. You might also need a herbicide applied for about two years to remove this thistle effectively. How to control it: Maintain a dense, healthy lawn to keep this weed at bay. Dig out this fast-growing grass, including the roots, as soon as you see it in your garden. It’s easiest to pull when the soil is moist. A non-selective herbicide like glyphosate can be used to control a small infestation. How to control it: Pull out this annual weed by hand or hoe before it seeds, removing the entire root. Afterward, mulch about 3 inches deep. Otherwise, use an herbicide (MCPA or 2,4-D) in early spring before it can flower. It grows erect, up to 15 inches tall, with stems that grow at a sharp angle (about 90 degrees) from the main stem. It has seed pods that bend sharply upward on their stalks. They may form colonies arising from slender but tough underground stems (rhizomes) but, more often, are individual, seed-grown plants. The weak stems branch at the base and sometimes will root at nodes. It can grow in most soils and conditions, even in the sidewalks’ cracks. How to control it: Common yellow woodsorrel is best managed by hand weeding and mulching. It pulls up easily and does not rebound from roots left behind. Remove plants before seed pods develop. Most herbicides are ineffective, but you can try pre-emergent herbicides to prevent germination. How to control it: To control it, keep your lawn thick and healthy. It has a hard time establishing itself when competing with dense, vigorous turf that is maintained at adequate mowing heights, fertilization rates, and irrigation practices. If some mallow seeds sprout, pull young plants before they go to seed. The roots go deep and can spread up to 2 feet. You can also use pre-emergent and post-emergent herbicides to control it. How to control it: Pull or remove it with a sharp hoe before it goes to seed. It has a short taproot, so it pulls up easily. The plants die with the first frost and next year’s plants grow from the seeds they leave behind. How to control it: Pull out this weed before it flowers. Also, its seeds require light for germination, so to prevent pigweed seeds from germinating, cover your garden with a 3- to 6-inch layer of winter mulch. You can identify them by their triangular stems. Roll the stems between your fingers, and you’ll understand the saying, “sedges have edges.” In contrast, grasses have round stems. Shiny, smooth nutsedge leaves have a distinct center rib and form a “V” shape. How to control it: These plants spread by seed and remain alive perennially because of their underground rhizomatous root or small tuber, called a nutlet. Some of these tubers can go as deep as 18 inches, which is why this plant can return yearly. Remove these plants as soon as you’ve identified them; do not allow them to develop tubers. Tubers develop about four to six weeks after the shoot. Most herbicides can’t reach deep nutlets. How to control it: Mulch the garden to prevent it from germinating and use a pre-emergent herbicide in the spring for problem spots. You can also hand pull or use a non-selective post-emergent herbicide. How to control it: Single plants can be easily pulled or dug up before they go to seed. Mulch your garden to prevent velvetleaf, or use a pre-emergent herbicide in spring. Do not till or plow infested areas because this promotes seed germination. Crop rotation can stop velvetleaf from returning. How to control it: Mulch garden beds in spring to prevent wild violet. Properly fertilize, mow, and water lawns to encourage dense growth that discourages wild violets from taking hold. Pull weeds by hand or spray with a post-emergent herbicide in spring or fall. How to control it: It reproduces from seeds. Pull plants by hand or apply a post-emergent herbicide once it grows. To prevent this weed, mulch garden beds in spring. How to control it: Use a mulch or a pre-emergent herbicide in spring to prevent quickweed. These plants have a shallow root system and are easy to pull by hand or spot-treat with a post-emergent herbicide. How to control it: Prevent pokeweed with a deep layer of mulch. Once the plant grows, hand-pull or spot-treat it with an herbicide. If allowed to establish, it will develop an extensive root system that will need to be dug out. If removing, bag its berries so they can’t reach the soil. If seeds are in the soil, use a pre-emergent herbicide before seeds have a chance to germinate. Consider using it in addition to a post-emergent herbicide. How to control it: Mulch your garden to prevent black nightshade. Pull the weed by hand or treat it with a post-emergent herbicide. How to control it: It has difficulty establishing itself in dense, well-kept lawns. Spread mulch to prevent black medic in gardens. Pull or dig out weeds by hand before flowering and seeds set. It should be easy to pull when the soil is moist. You can also use a post-emergent herbicide, best applied late spring through early summer and mid-autumn. How to control it: Prevent poison ivy with a deep layer of mulch. Spot-treat it with an herbicide or wrap your hand in a plastic bag or waterproof gloves and pull the plant up, roots and all. Carefully invert the plastic bag around the plant, seal it, and throw it away. It does not do well with repeated tilling, cutting, or mowing.
