6/1/2008 10:28:00 PM Top ten nasty weeds in North Florida can pop up anywhere and spread quickly in lawns and gardens
Sharp thorns on the wild blackberry (top) and catbrier vines put them in the list of top 10 nasty plants in North Florida. (Don Goode photos)
Sandspur (clockwise, from top left), Florida pulsey, carpetweed and chamberbitter grow nearly everywhere, spread quickly and are tough to eliminate. (Don Goode photos)
Whether you consider them part of God's curse during the exile from the Garden of Eden or part of nature's diversity for the struggle of plant dominance, we all deal with weed problems. In the lawn or in the garden - a weed can be defined as "a plant out of place."
We have several annual weeds that pop up during the cool season, bloom, set seed for next year and then fizzle with the summer heat. I generally don't recommend much in the way of control measures for these "temporary" weeds and in fact many make nice wildflowers if you mow around them!
Other weeds of a more troublesome nature can take over the yard or garden if you turn your back on them. Let's look at some of these pesky plants and some control options to consider.
Blackberry - Some wild blackberries are nice to have along an obscure fence row or corner of a pasture so you can have the free fruit. If they are in the yard, that is another matter. It can be difficult to pick the berries without getting snagged and scratched by the thorns. Mowing frequently will suppress them but you may need to use a herbicide labeled as a brush killer. The active ingredient of "triclopyr" is common in these products. Be careful not to spray any desirable shrubbery or trees with this herbicide. You could also excavate the plants (the roots make a tea that is good against diarrhea) but be sure not to leave any roots behind or they will resprout.
Catbrier - This viny plant is common along the edge of forested areas. There is often a tuber underground ranging from the size of a golf ball up to a football or two. This storage tuber makes it difficult to kill the vine so regular diligence is needed. You can try digging up the tubers or doing a weekly cut back of the shoots until you deplete the tuber of its energy. Otherwise, consider using the brush killer herbicide mentioned earlier. Cut down the vine and then spray the regrowth with the herbicide. Repeat applications may be needed until the tuber gives up the fight.
Florida Betony - This cool season weed has a small tuber underground that makes it difficult to kill. The tuber is white and slender with lumps and ranges from 1 to 3 inches long. Since the tuber resembles the tail of a rattle snake, the weed is often called "Rattlesnake weed." You could dig up all the tubers and make homemade pickles (they are excellent by the way) but they are likely to come back from the tubers you miss. An herbicide with the active ingredient of Atrazine is recommended but do not use Atrazine on a lawn containing bahia grass.
Florida Pusley - This weed tends to over run my garden each summer. It has a low growing format and makes small white flowers. Hand pulling is an option but it can get away from you. A pre-emergent herbicide such as Preen (containing the active ingredient of trifluralin) would be an option if used before the weeds germinate. Spot treatment of a non-selective herbicide such as Roundup would be OK too if you keep the herbicide off your desirable plants.
Chamberbitter - This little weed looks like a baby Mimosa tree of 2-8 inches tall. Under the leaf stem there are tiny seed sacks that explode when they mature and scatter the seed several feet in all directions. In a short time frame you can have a yard full! Preemergent herbicides such as Atrazine, Pendimethalin or Benefin (labeled sometimes as crabgrass preventer) can be used early in the season to prevent the weed seeds from sprouting. Pull the weeds you can and throw them away (but not in the compost pile).
Dollarweed - Sometimes blamed on overly moist soil, dollarweed spreads quickly from underground runners. I've seen it growing on dry sand dunes so I'm not sure it can be controlled by turning down the irrigation system. In flower beds you can spot treat with Roundup or other non-selective herbicides. In the lawn, Atrazine or 2,4-D products will slow it down.
Carpetweed - This is another low lying weed that can form a dense mat over time. Hand pulling works early in the season but an herbicide treatment may be necessary later on such as Roundup. Pre-emergent herbicides used early in the year can help prevent this annual weed from sprouting.
Crab Grass - In the garden this grassy weed is a real problem. The little sprouts that you ignore today will be large competitive grass plants next week. Preemergent herbicides such as Preen can be used around flowers and vegetables. A grass killing herbicide such as those containing sethoxydim as the active ingredient can be used over the top of existing flowers and vegetables to kill grassy weeds.
Doveweed - This low-lying weed resembles a small Wandering Jew plant. It can form a thick mat and chokes out existing lawn grasses. An herbicide with 2,4-D can be used to slow it down but the best treatment is a pre-emergent herbicide such as Atrazine, Pendimethalin or Benefin (crabgrass preventers) early in the Spring in areas where this weed has been an historical problem.
Sandspur - This weed I would place at the pinnacle of "nastiness" for our list. This annual weed can be managed with frequent mowing (using a bagger) or by hand pulling. If you can prevent this year's seeds from maturing, there will be less sandspurs for next year. A pre-emergent herbicide can be used in trouble spots early in the year to prevent the seeds from sprouting.
Many of these weeds can be controlled with mulching, hand pulling, frequent mowing and encouraging the vigor of the existing lawn or crop plant. In this case, a clean lawn and garden makes for fewer problems down the line. A little prevention goes a long way toward weed control.
Posted: Wednesday, July 13, 2011
Article comment by:
I am having a tough time identifying this weed. It has been in my yard for 30 yrs and I am ready to kill it. It is the hitchhiker as we have always called it. it produces many small green seed pods that stickj to your socks...dogs fur, etc...it grows a meaty, running root system that spreads and becomes hard like wood. I cant find them on any florida weed chart. WHat is the name of this weed?? thanks Mike