by Les Harrison | Apr 23, 2018
Spring 2018 is barely out of the starting gate. All kinds of plants are sprouting and producing blooms! This week’s last gasp of winter temperatures slowed the progress, but only slightly.
Much like the Easter egg hunts a few weeks ago, a search of the landscape can bring multiple surprises. Two colorful plants, spiderwort and rustweed, which are growing in the region fit into this category.
Tradescantia ohiensis, the scientific name for spiderwort, is a herbaceous native plant. Its most striking feature which makes it easily identifiable is the cluster of bright purplish-blue blooms which are currently on display.
Spiderwort in full flower. Image Credit Les Harrison
To the casual listener, the name spiderwort implies an arachnid with a complexion issue. Far from it, but the terminology is shrouded in agriculture and horticulture history.
The term wort, in its various forms, can be traced back to northern Europe to well over 1,000 years ago. Its meaning related at first to herbs, and then to plants without bark or hard stems.
It should not be confused with wart, a skin eruption relating to a virus. Contact with any part of the spiderwort does not infect a person with warts.
The spider part of the name relates to the flower peddles. In harsh sunlight of the afternoon, the Spiderwort’s peddles are reduced to fine threads similar to a spider’s web.
Spiderworts are often seen along fencerows, in pastures and untended fields, and it forested areas. They bloom from late spring to early summer and usually grow in clumps or bunches of plants.
The plant clumps are easily separated and transplanted. Spiderwort has been used in ornamental horticulture as a showy, low-cost alternative for many years.
They expand their presence in the wild slowly, but persistently. Since there are no herbicides labeled for their control, they are considered a pest species by some hay producers.
Another plant with a colorful name, and which is considered a pest, is the rustweed (Polypremum procumbens). While it does not literally rust, it gets its name from its rust colored foliage in the autumn.
In spring and summer this low growing perennial is a Kelly green fitting for St. Patrick’s Day, and easily blends with Bermudagrass and other turfs as they make their season emergence. Tiny white blooms soon to come will confirm it presence, but this is often overlooked when in landscapes and lawns.
This plant spreads by seed, which are small and heart-shaped. One means of colonizing new areas is by seed lodging in mowing and other equipment, then depositing in new areas when the equipment is relocated.
As with all grasses in the Florida panhandle, rustweed is found only in sunny areas. This little known plant is an area native, but also occurs as far away as South America.
Rustweed, among others, in a Florida lawn. Image Credit Les Harrison
This aggressive native will quickly establish itself and push out other more desirable species. Mowing will not slow its progress.
After the multiple frost and muted earth tones, both spiderwort and rustweed are currently adding variation to the landscape’s hues as the weather warms.
To learn more about weeds in north Florida, contact your local UF/IFAS County Extension Office. Click here for contact information.
by Larry Williams | Apr 16, 2018
Cold injury to lawn. Photo Credit: Larry Williams
Patience, warmer soil temperature and correct lawn management will solve many spring lawn problems.
Many spring dead spots in lawns are caused by something that happened the previous growing season or winter. For example, a late application of a high-nitrogen fertilizer can decrease winter survival. It’s best to not fertilize our lawns after early September.
An insect or disease problem during fall many times goes unseen as the grass is beginning to go dormant. The following spring, as the lawn begins to green up, evidence of a fall pest is clearly visible by brown dead, grass. The pest may not be present or active during spring.
Poor maintenance practices may be to blame for spring dead spots. Over-watering, shallow watering (watering frequently for short periods), mowing too low, too much fertilizer and herbicide injury can result in poor lawn performance come springtime.
Regardless of cause, problem areas within lawns are slow to recover during spring due to frequent cool night temperatures. Frequent cool nights keep the root zone cool.
Cool soil temperature doesn’t allow rapid root regeneration in spring, which inhibits top growth in your lawn. Cool soil also decreases availability of some needed nutrients. For example, poor availability of iron because of cool soil is a common cause for bright yellow areas within lawns, especially in centipedegrass. Cool soil also decreases availability of phosphorus and potassium, which can result in reddish-purple grass blades, intermingled throughout the yard. As soil temperature increases, availability of nutrients improves and the yellow and purple areas turn green.
Have patience with your lawn and follow good maintenance practices this spring. Provide ½ to 1 inch of water when the grass shows signs of wilt. Fertilize and lime based on the results of a reliable soil test. And, mow at a high setting. Good lawn maintenance info is provided at the YourFloridaLawn website.
Consistently warmer nights will allow the soil temperature to warm, which will improve turf root growth, nutrient availability and lawn recovery. During many years in North Florida, it’s well into the month of May before our lawns begin to recover.
If the lawn has not made a comeback by late spring or early summer, it may be time to consider reworking and replanting the dead areas or maybe consider replacing them with something other than grass, if practical.
by Matthew Orwat | Oct 10, 2017
Burweed, Soliva Sessilis. – Image Credit: Joseph M. DiTomaso, University of California – Davis, Bugwood.org. Creative Commons License
On the top of my list of lawn related annoyances is stepping into a patch of burweed, Soliva sessilis, which is in the sunflower family and is also known as spurweed. The leaves are opposite along the stem and sometimes resemble parsley. The main ways in which burweed can irk the casual gardener are sticking to socks, sneaking in with the dog, or littering flower beds with its nuisance. It can also hide in the house and reappear when shoes are removed. This causes pain in both the foot and the ear.
Lawn burweed has been an especially noticeable problem in lawns. Over the years, extension offices throughout Northwest Florida have been fielding many questions and finding solutions to lawn burweed infestations!
Maintaining a healthy vigorous lawn will prevent weeds from taking over. If your lawn is reasonably healthy and only a few instances of this weed exist, try to mechanically remove them and encourage the lawn to outgrow them.
If an infestation of burweed occurred last year on a specific patch of turf, take note. The best time to apply pre-emergent herbicides to control burweed is in October, when nighttime temperatures drop to between 55-60 degrees F for a few consecutive nights. A widely used pre-emergence product for burweed control is isoxaben, which is sold under the brand name of Gallery as well as others. It prevents the weed from emerging from the ground when it germinates and can be used on St. Augustine, centipede, bahia and zoysia lawns, as well as in ornamental shrub beds. In northwest Florida, this herbicide needs to be applied in October for best results. A second application later in the season might be warranted. For more information about control, please consult this excellent article on lawn burweed management.
Now is the time to control burweed before it gets started. As temperatures cool burweed seed will germinate, as it is a winter annual. In cases where it is already coming up, control with post-emergent herbicide may be warranted.
The active ingredients mentioned above are present in a variety of ‘trade name’ products* available from your local garden center, farm supply or co-op. Be sure to read label instructions carefully and contact your local extension office for any assistance. I hope all the northwest Florida lawn managers prevent burweed this fall so that lawns will be burweed free next spring.
Happy Gardening!
by Sheila Dunning | Aug 17, 2017
If you are one of the many that have taken advantage of the frequent rain in order to establish a new lawn, keep an eye open for “grass worms”. Though truly caterpillars, not worms, these destructive, chewing insects can wreak havoc on new sod.
Sod Webworm Photo by: Lyle Buss UF
Tropical sod webworm larvae are destructive pests of warm season turfgrasses in the southeastern U.S. especially on newly established sod. Larval feeding damage reduces turfgrass aesthetics, vigor, photosynthesis and density, which is very evident on finer-bladed grasses such as bermudagrass and zoysiagrass. Adults, a dull brown colored moth about ¾ inch long, rest in sheltered and shrubby areas during the day and are active at dusk. Females deposit clusters of 10-35 eggs on the upper surface of grass blades. The eggs hatch in 3-4 days and develop from a 1 mm long caterpillar to one over 11 mm long through six instars within 21 to 47 days, depending on temperature. Larval feeding occurs at night, leaving the grass looking ragged, shortened and missing.
Control should be against damaging larvae, not the flying moths. However, insecticidal soap applications to moth harboring areas can reduce re-population frequency if such areas are located. Soil-drenching soap flushes can be used to find the caterpillars, especially in dry and hot grass areas. Bacterial-based insecticides will control sod webworm caterpillars without impacting beneficial species as long as they are applied with each flush of grass growth.
Excessive fertilizing will lead to caterpillar outbreaks in lawns. Newly installed sod is usually rich in nutrients and rapid growing, which makes it very attractive to sod webworms. Grass installation over the summer months should be immediately followed by sod webworm treatment.
Fall Armyworm Photo by: Lyle Buss UF
Fall armyworms are also attracted to newly installed sod. They feed any time of the day or night, but are most active early in the morning or late in the evening. The 1 ½ inch long gray and white moth lays about 1,000 eggs in multiple masses on any vegetation. Two to 10 days later, the small caterpillar hatches and begins to grow to nearly 2 inches long over a two week period. The fall armyworm is easily recognized by its dark head marked with a distinct pale-colored inverted Y and the long black stripe running along each side of its body. These aggressive feeders “march” rapidly across grassed areas consuming every above-ground plant part. While bacterial-based insecticides will reduce the numbers, control of armyworms usually requires synthetic insecticides. Diligent inspection and early pesticide application is critical to establishment of new sod installed during the summer months.
by Mark Tancig | Aug 1, 2017
Florida’s panhandle has received quite a bit of rain this summer. In the last three months, depending on the location, approximately 15 to 35 inches of rain have come down, with the western panhandle on the higher end of that range. In addition to the rain, we all know how hot it has been with heat index values in the triple digits. And who can forget the humidity?! Well, these weather conditions are just the right environmental factors for many types of fungi, some harmful to landscape plants, most not.
In the classification of living things, fungi are divided into their own Kingdom, separate from plants, animals, and bacteria. They are actually more closely related to animals than plants. They play an important role on the Earth by recycling nutrients through the breakdown of dead or dying organisms. Many are consumed as food by humans, others provide medicines, such as penicillin, while some (yeasts) provide what’s needed for bread and beer. However, there are fungi that also give gardeners and homeowners headaches. Plant diseases caused by various fungi go by the names rusts, smuts, or a variety of leaf, root, and stem rots. Fungal pathogens gardeners may be experiencing during this weather include:
- Gray leaf spot – This fungus can often show up in St. Augustine grass lawns. Signs of this fungus include gray spots on the leaf (very descriptive name!). This disease can cause thin areas of lawn and slow growth of the grass.
Gray leaf spot on St. Augustine grass. Credit: Phil Harmon/UF/IFAS.
- Take-all root rot – This fungus can attack all our warm-season turfgrasses, and may start as yellow leaf blades and develop into small to large areas of thin grass or bare patches. The roots and stolons of affected grasses will be short and black.
Signs of take all root rot. Credit: UF/IFAS.
Powdery mildew – This fungus can be found on many plants, from roses to cucumbers. It looks like white powder on the leaves and can lead to plant decline.
- Armillaria root rot – This fungus can infect a variety of landscape plants, including oaks, hickories, viburnums, and azaleas. Symptoms can include yellowing of leaves and branch dieback, usually in adjacent plants. Old hardwood stumps can harbor this fungus and lead to the infection of nearby ornamentals.
Because fungi are naturally abundant in the environment, the use of fungicides can temporarily suppress, but not eliminate, most fungal diseases. Therefore, fungicides are best used during favorable conditions for the particular pathogen, as a preventative tool.
Proper management practices – mowing height, fertilization, irrigation, etc. – that reduce plant stress go a long way in preventing fungal diseases. Remember that even the use of broadleaf specific herbicides can stress a lawn and exacerbate disease problems if done incorrectly. Since rain has been abundant, irrigation schedules should be adjusted to reduce leaf and soil moisture. Minimizing injury to the leaves, stems, and roots prevents stress and potential entry points for fungi on the move.
If you think your landscape plants are suffering from a fungal disease, contact your local Extension Office and/or visit the University of Florida’s EDIS website at http://edis.ifas.ufl.edu for more information.
by Blake Thaxton | Jul 21, 2017
Northwest Florida has experienced an enormous amount of rain this summer. The western panhandle has received over 29 inches of rain since the beginning of May according to the Florida Automated Weather Network station at the West Florida Research and Education Center in Jay, Florida. That is 44% of average annual rainfall in less than two months. All of this rain has probably thrown off the normal lawn mowing routine. It is hard to get out and mow the lawn when its pouring buckets or the lawn resembles a swamp. With all of this in mind, there are a couple of mowing pointers that would be useful to implement to address the out of control lawn growth and the challenges posed by not being able to stick to normal mowing schedule.
- Always attempt to mow at the IFAS recommended height for your species of turfgrass. The recommended heights are determined by how quickly the species grow in our climate. The chart below shows the best heights at which to mow your lawn. The fine textured zoysiagrasses are not listed but should be mowed at 0.5 to 1.5 inches. Check the lawn mowers mowing height by measuring the distance from the ground to the bottom of the mowing deck on a flat surface.
From Mowing Your Florida Lawn: http://edis.ifas.ufl.edu/pdffiles/LH/LH02800.pdf
- When you do get out to mow, never remove more than 1/3 of the leaf blade. If you cut to short you will “scalp” the turf and cause a brown look on the lawn. This can be damaging to the turf and allow for weeds to get established by exposing the soil to the sunlight. What is taking place more in northwest Florida is not mowing frequently enough and cutting off excess growth due to the rain. This also can cause scalping so it is very important to mow frequently enough to only remove 1/3 of the leaf blade.
A zoysia lawn that has been “scalped” after excess growth and infrequent mowing. (Photo Credit: Blake Thaxton)
Other practices such as keeping your mower blade sharp, mowing in different directions, and leaving clippings on the ground will help keep a healthy Florida lawn. Please see more information about mowing correctly in Florida in the University of Florida/IFAS Extension publication: Mowing Your Florida Lawn
