eWeeds

What is a weed?  I guess a rose is a weed if it is growing in your lettuce garden!

Weed Management in Home Lawns--a UF Publication

 

 

Common Florida Weeds--from advanced tech   and ONETWO TREE

There are generally three types of weeds common to Florida: sedges, grassy weeds and broadleaf weeds.

  Goose Grass

Goosegrass - Eleusine indica
Annual forming rosette of flat stems, usually silvery at center. Leaves are folded in the bud with overlapping sheaths. 
Membranous ligule with sparse hairs on collar. Seed head forms two to ten finger-like spikes,  
zipper like, much broader than crabgrass. Germinates later than crabgrass. Persists under close mowing, even on putting greens.

Sedges

Included in this group are yellow nutsedge, purple nutsedge, globe sedge, kyllinga, and annual sedge (a.k.a. known as watergrass). Sedges typically thrive in wet areas that are over watered or have poor drainage. They are mostly perennial and spread by seeds or underground tubers.

Once established, sedges can be difficult to control. Repeated applications of weed control products throughout the growing season along with correcting the conducive conditions that allowed the sedge to establish will provide a degree of relief.

 Nutsedge - Cvperus esculentus (yellow) Cvperus rotundus (purple) Also known as nutgrass, but is not a grass. Perennial, reproducing by seeds and nut like tubers on roots. Stems erect triangular. Leaves 3-ranked, narrow, grass-like basal. Seed on un mowed plants arranged in narrow spikelets on umbel like inflorescence. Yellow nutsedge has single fleshy tubers on ends of roots. Purple nutsedge has strings of tubers on wiry rhizomes.

 

 kyllinga sedge  nutsedge

Grassy Weeds

CrabGrass

Crabgrass - Digitaria sp. Several species that are true annuals. Peak germination by early summer. Yellow green leaves rolled in the bud with hairy edges, coarse textured, broad collar, membranous liguile and hairy sheath. Blade flat with sharp point. Seed head composed of three to ten finger like racemes or spikes, may appear purple to tan in color. Plant declines after seeding with shorter days. Eliminated by frost. Occurs all over the U.S., although less in the North than the South. Mostly in full sun.

 

 

This group includes alexandergrass (a.k.a. creeping signalgrass), sandbur, crabgrass (several varieties), torpedograss, goosegrass, thin paspalum and creeping bermudagrass.

Alexander grass 

Selectively controlling grassy weeds, once they are established (especially in St. Augustine grass lawns), is nearly impossible. Applications of pre-emergent herbicides in fall and winter, before the weeds emerge, helps prevent weed establishment. It also may be necessary to cut out and physically remove these weeds and then replace with new sod.

Another remedy would be to edge the entire weed-filled area (cutting through desirable grass stems and runners) and then treat with Round-Up non-selective herbicide. A second Round-Up application may be required before re-sodding. Hopefully, the new replacement sod will not contain excessive weeds or weed seeds that will result in a new weed issue.

Here is an Advance Tech Tip for eliminating small spots of crabgrass in St. Augustine grass lawns… lightly scatter baking soda on damp crabgrass spots at the rate of 1 # baking soda per 100 square foot area. This will kill the weed without damaging the St. Augustine grass!

 Spurge

Spurge - Euphorbia maculate & E. supine A summer annual that begins germination from seed when soil temperatures reach 85° F and continues all summer long. Small, oval, opposite leaves vary from dark green to red with a brown blotch on the upper surface. Reddish low growing stems, that fan out from the tap root, form a dense mat. Milky sap is sticky. Prolific seed producer, several thousand from one plant. Plant matures in a matter of days in hot weather.

MatchweedMatchweed -  Phyla nodiflora Matchweed is a mat-forming perennial with opposing leaves on hairy branching stems. Leaves have small teeth at the outer tip. The purple to white flowers emerge around the tip of the seed stalk forming a match-head appearance. Matchweed spreads by both seeds and stolons along prostrate stems.

Broadleaf Weeds

Broadleaf weeds include Asiatic hawksbeard, spurge (several varieties), creeping beggarweed, oxalis (yellow and purple), Florida pusley, pennywort (a.k.a. dollarweed), and matchweed (a.k.a. creeping Charlie). Herbicide applications can only be made when temperatures are below 85 degrees F. in the late fall, winter or very early spring. Subsequent control is achieved by hand pulling.

dollarweed

Pennywort ( Dollarweed ) - Hydrocotvle sp. A perennial growing from rhizomes, tubers and seed. Erect leaves with scalloped margins on a long petiole in the center of an umbrella like leaf. Found in moist to wet sites. Most common in Transition Zone, South.

       oxalis

Pusley  ..Florida pusley is a summer annual found most often in warm season turfgrass areas. The leaves can be hairy and are grow opposite one another on hairy stems. The growth of Florida pusley in maintained turf areas is usually low and prostrate to the ground, forming thick patches. The growth can be erect with infrequent mowing. Florida pusley usually will not root at the nodes. The flowers are white and grow in clumps at the end of the stems. The flower is star shaped with six parts connected to form a tube. Florida pusley will flower anytime the temperature is above freezing. Florida pusley spreads by seed. Florida pusley is found in areas of the United States where warm-season grasses proliferate.

  Hawksbeard

Broadleaf Plantain - Plantago rugelii and Plantago major A perennial rosette reproducing from seed. Leaves are large, rounded and deeply veined with wavy edges and purple petioles. Seed stems resemble a rat's tail and support small flowers and seeds. Long tap root, similar to Dandelion, increases plants' hardiness to stress and herbicides

 

Bull Thistle - Cirsium vulgare Bull thistle is a biennial growing into a rosette with large, fleshy, coarsely-toothed spiny leaves. The second year, a woody, flowering stalk produces a few, rose-purple blossoms. Produces less flowers than Canada Thistle but all flowers are fertile.

Yellow Woodsorrel - Oxalis stricta Annual to short lived perennial, upright, with single tap root, spreads by seed. Leaves of three, heart shaped, pale green and bitter to taste due to presense of oxalic acid. Bright yellow flowers have five petals. Prolific seed producer, pods will scatter seed for several feet when touched.

Quackgrass - Agropyron repens
Blue-green rough bladed perennial reproducing by seed and aggressive rhizomes. Erect stems, leaves rolled in bud, sheaths hairy. Short membranous ligule, large, very prominent clasping auricles. Spike seed head resembling perennial ryegrass. Spreads throughout lawn and from ornamental beds. Very difficult to control

 

 

Dandelion - Taraxacum officnale Perennial with long tap root produces by seed. Stems short arising from a rosette bearing oblong, lobed, narrow leaves. Large yellow flowers mature into round puffballs full of seed distributed by wind for miles. Mostly germinates during late summer.

 

Old Farmers Almanac 

Crabgrass:
Crabgrass tops America's list of lawn complaints. A fast-growing annual that reproduces by seeds and by rooting at the lower joints. This weed appears from mid-spring through summer when the ground is warm. It grows well under dry, hot conditions. Go after crabgrass as soon as it appears in the garden. Dig it out by the roots with a spading fork or cover it with black plastic. Don’t let it go to seed.

To prevent crabgrass in the future, attack the problem in two stages.  In the early spring, apply corn gluten meal, an organic preemergent herbicide. Spring is when the soil is cold and the crabgrass is weakest. (Crabgrass is an annual weed, so it starts from seed every year. The preemergent herbicide prevents the seed from germinating--and if the seed can't sprout, it can't grow.) Second, re-seed your lawn in the fall. This will allow the new grass time to grow strong before the next summer's attack.

The best crabgrass preventer is a healthy, thick lawn, and soil with the proper pH balance (7.0-7.5). Perennial ryegrass is the best competition for crabgrass. It also provides some insect control, as it emits a natural poison that gives some small, damaging bugs the "flu." Fertilizing is key and must be done in the spring and in the fall. Crabgrass thrives in compacted lawns. Aeration can help. A mixture of 1 pint of hydrogen peroxide, diluted to 3 percent, per 100 square feet of lawn can help eradicate the pesky plant. Click image to enlarge. 

Pigweed:
An annual that reproduces by seeds. It is characterized by its fleshly, red taproot. This weeds appears in late spring or early summer and likes warm weather. Try to pull out this weed before it flowers.

To prevent weeds in the future, cover your garden plot with a winter mulch, then till the garden shallowly in early spring. When you till you may bring up some pigweed seed so it's best to mulch again. Cover the soil with five layers of wet newspaper and cover that with 3-6 inches of mulch.

Pigweed can also be eaten! In June, the young leaves of Amaranthus blitum or amaranth are abundant and should be eaten because of their high nutritional content. Vitamin-wise, these greens are packed like carrots and beets and can be delicious in a tossed salad. You can also cook them as you would spinach. Native Americans used the black seeds of this plant as a ground meal for baking. Click image to see more.

Chickweed

There are two species of chickweed, one perennial and one annual. Mouse-ear chickweed is the perennial, which forms a dense, prostrate patch in lawns and gardens. Common chickweed, the annual, is more delicate in appearance, with leaves that are broad at the base and about half an inch long.

Common chickweed is easier to control. Both types have shallow roots, so they can often be removed by hoeing or hand-pulling. New plants can grow from broken pieces of mouse-ear rootstock, however, so make sure you remove the entire plant when using either method.

A healthy lawn can compete against mouse-ear chickweed if the grass is not mowed too short or too frequently. Watering the lawn deeply and infrequently will encourage the grass to grow deeper roots, which also can help it compete against chickweed. Water once every seven to ten days, and apply enough water so that it soaks six to eight inches into the ground.

If you choose to remove chickweed, do it before the weed has time to go to seed, thereby preventing future problems in your garden area.  Click image to expand.

Morning Glory:
A common annual that reproduces by seeds and by deep, horizontal roots. This flowering vine sprouts in late spring and can be seen throughout the summer. This plant can become a big problem in warm weather. Try to dig out this weed before it flowers. Click image to see more.

 

Quackgrass:
A creeping, persistent perennial that reproduces by seeds. Its long, jointed, straw-colored rhizomes form a heavy mat in soil, from which new shoots may also appear. Try to dig out this weed as soon as you see it in your garden. Click image to enlarge.

 

Lambsquarters:
A fast-growing annual that reproduces by seeds. This summer weed rapidly removes moisture from soil, so remove it as soon as possible. Cultivate this weed out of your garden using a sharp hoe. Click image to see more.

 

Purslane:
An annual that reproduces by tiny black seeds and stem fragments. This weed appears in late spring or early summer and likes warm weather and rich, fertile soil. Pull or cultivate out this weed as soon as you see it and destroy the plant; this weed can live in your soil for years. Click image for a closer look.

 

Shepherd's Purse:
A flowering annual that reproduces by seeds. It likes cool weather and its yellowish-brown seeds are long-lived in the ground. Try to pull out this weed before it seeds. Click image for a closer look.

 

Buckhorn Plantain:
A hardy perennial that reproduces by seeds. This narrow-leaved weed invades meadows, pastures, and lawns. This weed appears in any season. Hand weed this plant and destroy it to remove it from your garden. Click image to enlarge.
 

Guide to Common LawnWeeds--link(Bayer)