Written by southernmedia• August 12, 2020• 3:37 pm• Herbicides, Lawn Tips, Staff's Picks

Ultimate Weed Identification Guide – With Pictures

Note: this weed identification guide is a work in progress. Therefore, we intend to update often so be sure to check back for updates.

Last Updated October 23rd, 2020.

Table of Contents for Weed Identification Guide

Annual Bluegrass

Sometimes referred to as Poa annua, this annual bright green grass will pop up in your lawn in the cool months, but may not be very noticeable until early spring. This grass will grow in clumps and can be identified by its smooth leaf. The end of the leave will have a boat-like appearance. Although it can bloom in the winter, spring months are when the fuzzy white seed heads begin to appear. Moist soils are more favorable for annual bluegrass growth. In areas with extensive infestations, bare spots may be left behind after control. It is important to reestablish sod in these areas to prevent establishment of more weeds. Since annual bluegrass spreads and grows each year from seed, it is important to control before it is given an opportunity to flower. Apply atrazine (Southern Ag Atrazine Weed Killer for St Augustine Grass) is in November and then repeat in early January. This product is safe for centipede grass, St. Augustine grass, zoysia grass and dormant bermuda.

Broadleaf Plantain

First up in our weed identification guide is broadleaf plantain. This broadleaf perennial weed can be identified by its oval leaves growing erect in rosette, or flower-like arrangement. In addition, flower spikes will grow outward from the rosette. These rosettes have seeds that attach unknowing passersby. Broadleaf plantain favors dry, compacted soils and will sprout from dropped seeds or regenerate from taproot. Post emergent control can be obtained by OneTime in bermuda, tall fescue, kentucky bluegrass and zoysia and 2,4-D in centipede.

Chamberbitter Weeds

This lawn weed is a summer annual that grows beginning in the early summer. Subsequently, by mid-summer you can easily identify it. Resembling tiny mimosa tree sprouts, other names include “little mimosa” and “gripeweed”. Chamberbitter will have multiple branches. Furthermore, small leaflets on opposite side and across from each other will line the entire branch. Additionally, small ball-like seeds will develop on the underside of the branches. In conclusion, chamberbitter an annual. This means it’s best to control Chamberbitter in the early summer before it has begun to seed. Use an atrazine as a preemergent in centipede and st. augustine lawns. Isoxaben can also be used in centipede and st. augustine, as well as tall fescue, bermuda, and zoysia.

If Chamberbitter has already sprouted, use trimec on small plants in tall fescue, bermuda and zoysia lawns. Likewise, for st. augustine and centipede, atrazine can be used as a post emergent. However, after it seeds, homeowners waste time and money trying to treat it since it dies shortly after.

Clovers

There are numerous species of clovers that may find their way into your lawn. These weeds will begin by seeds and then spread through seeds and rhizomes. Easily identified by their trifoliate (three leaves) low growth pattern. Leave will also likely have a light white triangle on the leaves. Flowers will grow in clusters and may be white or pink. This family of plants will grow in the spring, summer and fall, but is most noticeable when it flowers. Able to fix its own nitrogen, it can be helpful to your lawn in small amounts, but too much can result in a patchy lawn. Therefore, the best avenue is to control clover as soon as it is noticed. In centipede grass or fescue with heavy infestations, it is best to use what the pros use. Tenacity is an excellent choice for a weed killer. Fertilome Weed Free Zone is a combination of weed killers and is safe for bermuda grass, St. Augustine grass, centipede grass and zoysia grass in the winter.

Common Chickweed

Chickweed is a winter annual that begins to sprout in the fall. It can easily establish in thin turf areas or dormant lawns. Chickweed will grow throughout the winter and begin seeding in the spring\summer before dying. This plant can form dense mats of tiny egg-shaped leaves arranged in pairs opposite on the stem. The stem has a single line of hairs running along the leaf stem and main stem. Flowers form on the end of the stem and have five white petals. Isoxaben can be used in centipede and St. Augustine, as well as tall fescue, bermuda, and zoysia lawns as a preemergent. Your best bet to control of established chickweed is with the weed killer Southern Ag Lawn Weed Killer with Trimec. It’s safe for St. Augustine, centipede, bermuda, zoysia and tall fescue lawns.

Common Lespedeza Weeds

This extremely common summer weed has three, oblong leaflets with smooth edges. These leaflets also have distinctive, parallel veins that connect into a midvein. If you let this weed hang around in your yard too long, the stem becomes woody. Common lespedeza has pink to purplish flowers. Common lespendeza is a legume Therefore, its seeds are produced in a bean pod. Your best bet to control lespedeza is in the early spring with the weed killer Southern Ag Lawn Weed Killer with Trimec. It’s safe for St. Augustine, centipede, bermuda, zoysia and tall fescue lawns.

Crabgrass

No weed identification guide would be complete without crabgrass! Crabgrass is a summer weed that sticks out in your lawns like hives from a bad shellfish allergy. This large, wide bladed grass has smooth edges and crinkled at the base. Hairs are also common where the leaves connect. Seed heads grow throughout the summer and has six long spikes. In fescue, zoysia and bermuda lawns we recommend controlling crabgrass after it has begun to develop with Ferti-Lome Weed Out with Crabgrass Killer RTS. In centipede lawns use Arrest for best control and Southern Ag Atrazine for fair control in St. Augustine lawns.

Dandelion

I’m sure you have childhood memories of blowing on the puffy seedheads of dandelions. However, now that it is growing in your lawn you feel different. This perennial is easily identifiable by its seed head and yellow flower. However, recognizing it before it blooms can give you the upper hand on control. Leaves are notched and resemble spearpoints in a rosette pattern. When the leaves or stem is broken, a milky white sap will flow. Dandelions can regenerate from their taproot every year.

Post emergent control can be obtained by OneTime in bermuda, tall fescue, kentucky bluegrass and zoysia and 2,4-D in centipede.

Florida Betony

Florida betony is a winter perennial in the mint family. This plant’s roots, or tubers, resemble the rattles on a rattlesnake, hence another frequently used name is rattlesnake weed. These tubers are edible and can provide a nice crisp crunch to your salad. Other distinguishing characteristics include a square stem and leaves on opposite sides of the stem from each other. Pink to light purplish flowers will emerge in the spring.

The opportune growing time for Florida betony is in the spring and mid to late fall. Therefore, this is the best time to kill this weed, with fall the most effective. It is important to use a weed killer that will move throughout the plant and kill the tubers as well. For centipede grass, St. Augustine grass, zoysia grass and dormant bermuda, Southern Ag Atrazine Weed Killer for St Augustine Grass is recommended. Apply this product in mid to late October and then repeat in mid to late February.

Florida Pusley

Even in the dry-dog days of summer, Florida pusley grows strong. This plant is extremely drought-tolerant. When your lawn is stressed and begins turning brown, this could be the only thing still growing. This summer annual grows outwards, or prostrate, instead of upwards. If not controlled, it can form a dense blanket infestation. Leaves grow on opposite sides of a hairy stem. Small star-like flowers cluster at the end of the stems.

Mowing frequently can prevent florida pusley from seeding, but it will not rid your yard of it. If caught early enough, Pendimethalin granules can be used as a preemergent. After established, 2,4-D in centipede and Carfentrazone (Quicksilver) in centipede, kentucky bluegrass, tall fescue, st. augustine and zoysia.

Ground ivy (creeping charlie)

This perennial herb, unless killed, will sprout year after year from its extensive root system. Ground ivy will likely pop up in areas of thin turf, in damp-shady areas. A cousin to mint, this plant has square stems and leaves opposite of each other. Leaves are rounded to kidney-shaped. Leaf edges have a rounded tooth appearance. Flowers are a violet-purple color. Your best bet to control ground ivy is in the early spring with the weed killer Southern Ag Lawn Weed Killer with Trimec. It’s safe for St. Augustine, centipede, bermuda, zoysia and tall fescue lawns.

Hairy bittercress

Hairy bittercress is an annual that will germinate from seed in the fall. Favoring shady and lawns that are mowed too short, this weed will grow throughout the winter before flowering in the spring. Initial leaves of hairy bittercress will be heart-shaped and remain close to the ground during winter. Spring will encourage upward growth with pairs of kidney-shaped leaves. White flowers will form before transitioning to long, wiry seed pods. Once these seed pods rupture, they are capable of shooting seeds up to 16ft from the plant. Green Light Amaze Grass and Weed Preventer is a great pre-emergent that is effective on a variety of broadleaf weeds, particularly hairy bittercress. Apply this granular weed killer in late winter in Tall fescue, bermuda, St. Augustine, centipede, zoysia, and bahia lawns. For already established bittercress, treat with Fertilome Weed-Out Lawn Weed Killer with Trimec in bermuda, bent, zoysia, fescue, St. Augustine, and centipede lawns.

Henbit

Henbit has rounded-toothed leaves that encircle half of a square stem. Paired with another leaf on the opposite side, the leaves appear to fully wrap around the stem. With a similar appearance to ground ivy, henbit grows erect (up to 16” high) instead of staying low to the ground. Furthermore, flowers of henbit are vase-shaped and purple. Also, each flower has reddish spots on the petal tips. This annual will begin growing in the fall of areas of bare or thin turf. Henbit will continue to grow during warm periods of winter months before flowering in the spring. Henbit cannot be controlled by mowing. Isoxaben can be used in centipede and St. Augustine, as well as tall fescue, bermuda, and zoysia lawns as a preemergent. Your best bet to control of established henbit is with the weed killer Southern Ag Lawn Weed Killer with Trimec. It’s safe for St. Augustine, centipede, bermuda, zoysia and tall fescue lawns.

Lawn Burweed

If you ever asked as a child “Are there any stickers?” before you walked across the grass, you were likely talking about lawn burweed. This annual has many names, stickerweed, sandspur, and spurweed. It is a pain in your feet as a child and is a pain in your @$ as an adult. Lawn burweed begins growing in the fall continues slowly growing throughout the winter. Leaves and stems are hairy and slightly resemble cross between parsley and rosemary. In the spring, burweed begins a rapid growth and develops the spiked seeds that plagued bare feet across the country. Isoxaben can be used in centipede and St. Augustine, as well as tall fescue, bermuda, and zoysia lawns as a preemergent in the early fall. You’re wasting time and money trying to apply a post-emergent in the spring. Post-emergent burweed control in St. Augustine, centipede, bermuda, zoysia and tall fescue, the best produce is Southern Ag Lawn Weed Killer with Trimec.

Nutsedge

Resembling a grass, nutsedge (yellow and purple), often grows faster than your centipede grass. The easiest way to identify nutsedge is by pulling up a plant and looking for the tubers or nutlets. Another distinguishing characteristic of sedges is their triangle shaped stem, which differs from the hollow ones of grasses. Since sedges aren’t grasses, standard grass weed killers will not kill it. The best weed killer for nutsedge is SedgeHammer. With a name like that, how can you go wrong? When applied according to the label, this product is safe on bermuda, centipede, tall fescue, St. Augustine and zoysia lawns.

Old World Diamond Flower

Old World Diamond Flower is a summer weed with smooth, oblong-pointed leaves that are arranged opposite of each other on the stem. The dainty, white flowers have a long stalk that connects multiple flowers to the weed stem. This weed can be difficult to control. There are no pre-emergent option available. Products like QuickSilver with carfentrazone can be an effective post emergent weed killer when used at the appropriate time. Safe for bermuda, St. Augustine, centipede and zoysia yards, however check the label for best application times.

Purple Deadnettle

Deadnettle is a winter annual that you may not notice until it begins to bloom early spring. However, it’s best to identify and control it during the winter while it is actively growing. If you wait until it flowers, you run the risk of seeds falling into your yard to give problems in future years. This weed is in the mint family, therefore has square stems and leaves opposite on the stem. The leaves are triangle shaped and bunched at the top. This makes the plant appear to be top heavy. Upper leaves will also have a hint of purple coloration overlaying the base green.

Deadnettle can be controlled after it begins to grow with the weed killer Fertilome Weed Free Zone. This product is a combination of weed killers and is safe for centipede grass, bermuda grass, St. Augustine grass and zoysia grass in the winter. In centipede grass with heavy infestations or history of deadnettle, it is best to use what the pros use. Tenacity can be applied before the deadnettle has appeared or after and will knock it out.

Purslane

Purslane is summer annual that grows between May and August. If left unmanaged, this weed grows in mats along the ground. This lateral growth pattern, instead of erect, is identified as prostrate and exhibited by several nuisance lawn weeds. Purslane can be distinguished by its succulent, or thick and fleshly, leaves and stems. Leaves are light green. Likewise, stems can vary from light green to maroon on older weeds and on its underside areas. Purslane has yellow flowers with 5-petals.

Prevention is the key by having a dense, healthy lawn. However, if purslane develops, it can be hand-pulled or treated with a weed killer. Preemergent weed killers include isoxaben in centipede and st. augustine, tall fescue, bermuda and zoysia yards. Simazine can be used in centipede lawns. Post emergent control can be obtained by OneTime in bermuda, tall fescue, kentucky bluegrass and zoysia and 2,4-D in centipede.

Spurge

You’ve likely seen this fast growing weed growing between the cracking in the sidewalk or parts of your lawn where there isn’t much grass. Spurge has a reddish brown stem and dark green leaves that are arranged opposite of each other on the stem. The most identifiable characteristic of this plant is the potentially irritating milky white sap that seeps out of broken leaves. This annual has a tendency to grow throughout the summer. If you let this one hang in your lawn long enough, a small white flower will show up on the end of the stems. You are not going to be able to mow spurge out of your lawn. Isoxaben can be used in centipede and St. Augustine, as well as tall fescue, bermuda, and zoysia lawns as a preemergent in the early Spring. Post emergent control can be obtained by OneTime in bermuda, tall fescue, kentucky bluegrass and zoysia and 2,4-D in centipede.

Virginia Buttonweed

This weed is often mistaken as a grass. However, if not treated and killed at the root, this perennial weed will plague lawns year after year. The leaves are a darker green on the top and connected directly to a slightly hairy stem. Virginia buttonweed flowers have white, star-shaped flowers with reddish-pink stripes. It is extremely hearty and cannot be mowed out of your lawn.

Virginia buttonweed is a perennial weed, meaning that it can regenerate from the roots in subsequent years. This means it will likely take multiple treatments to control. Apply Fertilome Weed Free Zone in the spring as it is beginning to grow.

Reminder This weed identification guide is constantly being added to. Check back often.

Wild Violets

This perennial will show up year after year in your yard and is one of the hardest to control. Early identification and maintenance is key to eliminating wild violets from your lawn. Most likely found in wet, shady areas of the yard, wild violet will spread quickly through an extensive rhizome system. There are numerous species of wild violets and flower colors can range from white, blue, purple and violet. However, the leaves of this family of plants will be heart-shaped and cupped to form a funnel-like appearance.

Wild violets are best controlled in the fall. Avoid hot dry times and begin your treatments after temperatures have dropped. Unfortunately, there is no effective weed killer that will eliminate wild violet before it grows. Also, be prepared to make multiple treatments to rid your yard of this nuisance weed. In dormant bermuda grass and zoysia grass, use TZone SE. In centipede grass, use Tenacity. Don’t be shell-shocked with the price of either of these, nothing cheap is going to kill wild violets.

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