by Julie McConnell | Sep 9, 2013
Fertilizer Spreader: Image Courtesy UF / IFAS Extension FYN Program
Although temperatures are still hovering around 90° F, the last fall fertilization date is approaching quickly. Mid-September is the
deadline for applying fertilizer to warm season turf-grasses and landscape ornamental plants for the year. Why is September 15 the cutoff date? In North Florida, our estimated first frost date is November 15. When fertilizer is applied the nutrients encourage new growth that typically takes about 6-8 weeks to become “hardened off” and able to tolerate low or freezing temperatures. So, simply backtracking on the calendar gives you an idea of when to make the last application of fertilizer (if needed).
If September 15 is at the end of our warm season feeding schedule, the next question should be “when should I fertilize in the spring?” Although Northwest Florida’s average last frost date is listed as March 15, UF/IFAS Turf Specialist Dr. Bryan Unruh does not recommend fertilizing before April 15 in the panhandle. There are two main reasons for this later date. One is that the March 15 last frost date is an estimate, many times cold weather follows a warming trend in late winter/early spring. During April of this year warm weather was followed by cool temperatures with cold winds that caused landscape plant damage. If fertilizer was applied before this weather arrived, some cold damage may have been evident this spring in affected landscapes. The second reason is that if fertilizer is applied to turf or plants that are not actively growing and using those nutrients, it may leach out of our sandy soils. Nutrients do not wait for plants to use them; they can be washed out and become a source of nonpoint source pollution.
To read more tips on fertilizing visit EDIS ENH1174 “The Lawn Fertilizer Toolbox”
by Larry Williams | Sep 2, 2013
Despite the fact that winter annual weeds are not currently growing, we are approaching the best time to prevent them from being seen in our North Florida lawns.
Carolina Geranium
Common winter annual weeds include annual bluegrass (Poa annua), chickweed, henbit, hop clover, lawn burweed and Carolina or wild geranium.
Annual Bluegrass Photo Credits: UF/IFAS
These and other winter annual weeds germinate from seeds in late fall and early winter. The little seedlings go unnoticed but continue to slowly grow through the colder winter months. Approaching spring, as day length becomes longer and soil temperatures warm, these previously inconspicuous weeds put on a growth spurt.
Lawn Burweed:
Close up of parsley-like leaves. Note sharp spines in leaf axils.
Photo Credits: Weeds of Southern Turfgrasses
During spring, the winter weeds may outgrow the lawn grass in our North Florida yards. They begin producing numerous flowers followed by thousands of seeds. For example, one chickweed plant can produce over 15,000 seeds.
In late spring or early summer with the onset of higher temperatures, the parent plants that started their lives from seeds the previous fall will die. But they leave behind a multitude of seed. These seed last the hot summer months dormant in your lawn. Then, in late fall and early winter, they germinate, beginning the entire cycle again.
Late September to early October, when nighttime temperatures drop to 55° to 60°F for several consecutive nights, is the time to apply a pre-emergence herbicide to interrupt the cycle of life for these winter annual weeds. This is just before seedlings emerge.
For season-long control, a second application may be needed about nine weeks after initial application. Not every lawn needs an application of pre-emergence herbicide. If your lawn has had no problem with winter annual weeds, there’s probably no need to apply a pre-emergence herbicide. Use pre-emergence herbicides only on lawns that have been established for at least a year. Many preemergence products interfere with grass seed germination. So, delay reseeding 6 to 16 weeks after application. This also applies to over-seeding a lawn with rye grass seed. Always follow label directions and precautions when using any pesticide, including herbicides.For specific pre-emergence herbicide recommendations, please consult this Weed Management Guide.
by | Aug 19, 2013
As if mowing the lawn wasn’t trouble enough, dealing with and disposing of grass clippings is a major pain.
Clumps of grass clippings left on the lawn are unsightly and cause the grass beneath them to turn yellow due to a lack of sunlight as well as oxygen.
That problem is somewhat eliminated if you have a bag attachment on your mower, but handling the grass clippings extends the chore of mowing by taking extra time and effort to repeatedly empty the bag. Then, once clippings are put in garbage bags and placed on the curb, our municipal waste handlers must deal with them.
What to Do?
On the other hand, if we manage our lawns correctly and use proper cutting practices, we can have nice lawns without bagging clippings.
Properly managed, grass clippings will not contribute to thatch buildup or other problems. As they decompose, grass clippings also can supply much of the nutrients needed by your lawn.
Since you’ve already got it, why throw it away?
Bag-free Lawn Care Plan
You can follow this bag-free lawn care plan using a traditional lawn mower:
- For an established lawn, cut at the lower recommended cutting heights for your grass and use the lowest recommended amount of fertilizer. Mowing grass at a lower height will discourage thatch build-up.
- The rule of thumb for when to mow is to remove no more than about one-third of the leaf area at a time. If this practice is followed, the clippings will be small enough to sift into the turf and naturally decompose near the soil surface.
- To be successful, you will need to mow frequently enough so that the clippings are not too large. This may mean that the lawn can’t necessarily wait until Saturday morning. You must also mow at the recommended height. To ensure that your blade is set at the recommended height, set the mower wheel height on a concrete surface.
Here are some recommendations on various grasses and the heights at which to mow the grass:
- Common Bermuda: mow at approximately 1½ inches.
- Hybrid Bermuda: mow at approximately 1¼ inches.
- Zoysia: mow at approximately 2 inches.
- St. Augustine: mow at approximately 3 inches.
- Centipede: mow at approximately 2 inches.
Under the bag-free plan, you may apply a second application of fertilizer to your lawn this month (The first application should have been done in late April.). But remember that fertilizing grass increases its rate of growth. Reducing the amount of fertilizer you apply to the lawn will reduce the amount of clippings you will have to deal with. However, the one turf I would completely eliminate from a second fertilizer application annually is centipede. Too much fertilization in centipede can cause many more problems than any benefits that may arise from it.
A complete turf fertilizer is recommended for the average lawn. The best is a blend with more nitrogen, little phosphorus and some potash. Fertilizers with nitrogen, phosphorus and potassium ratios of 3:1:2 or 4:1:2 are good for turf. Choose a blend that contains some controlled-release nitrogen for longer feeding.
Don’t forget that recycled clippings also add nutrients, so fertilize at one-half the recommended rates – or not at all – if the grass color, growth and general appearance are acceptable.
Other practices will add to your success. First, don’t over water your lawn. During the hottest summer period lawns don’t need more than about an inch of water a week. Water as needed for weather conditions, and wait until the grass actually shows some stress before watering. Drought-stressed lawns often appear slightly faded, and the grass blades may be folded or rolled up.
Cut your grass when the leaf blades are dry (wait for the dew to dry). The clippings will sift down to the soil better. Make sure your mower blades are sharp, and keep the mower housing clean for best cutting and movement of clippings. You may need to have your mower blade sharpened once or twice in the growing season to properly cut your grass rather than having a dull blade ear your grass.
If you own or are thinking of buying a mulching mower, you’ll find they do an excellent job of chopping grass clippings and fit very well into this kind of program. Because these mowers are designed specially to chop grass clippings finely and return them to the lawn, they are a bit more forgiving if you wait slightly longer than recommended before mowing. Always avoid letting the grass get excessively tall before you mow.
For more in depth lawn care information, consult “Your Florida Lawn” or contact your County Extension Agent.
by Julie McConnell | Aug 5, 2013
Chamberbitter
Above average rainfall this summer has supplied water to more than just our landscapes, weeds are benefiting and flourishing as well.
Just as with any other landscape pest, proper weed control starts with accurate identification and knowledge about the life cycle of the weed.
When weeds are low in number, mechanical control (pulling, mowing) is a good start. If weed population continues to increase and herbicide options are considered, several questions need to be answered before product application.
Questions you need to ask yourself about your weed and site:
- What weed(s) are you trying to control?
o Be sure you know what the name of the weed is so that you can find it on your product label “weeds controlled” list; if you need help with identification contact your local county extension office
- What is your site?
o Lawn – specific turfgrass is important, what is safe to use on one type may kill another
o Ornamental beds – again note specific plants near your treatment area in case of sensitivity
o Water bodies – some herbicides are not labeled for use within a given distance of water; if the weed is in or around the water only use herbicides listed for aquatic weed control
- What is the life cycle of your weed?
o Annual – one season life cycle, summer annuals complete their life cycle between spring and fall; winter annuals are active between fall and spring
o Biennial – two growing season life cycle
o Perennial – plant lives for three or more years
- What category does your weed fall into?
o Grasses – one seed leaf as it emerges from the soil; hollow, rounded, stems with nodes, parallel veins in true leaves; examples are crabgrass, dallisgrass, cogongrass, torpedograss
o Broadleaves – have two seed leaves and true leaves have net-like veins and usually have showy flowers; examples are lespedeza, dollarweed, clover, chickweed, henbit, florida betony
o Sedges/Rushes – sedges have solid triangular stems; rushes have round stems; both like moist or wet habitat; examples are purple nutsedge, yellow nutsedge, beak rush
Dollarweed: Image Credit Edis ENH1128
Basic information about herbicide categories:
For more information read EDIS Publication “Weed Management in Home Lawns”
by Larry Williams | Jul 22, 2013
Gray Leaf Spot is a common fungal disease of St. Augustinegrass. Recent wet conditions have promoted this disease. This includes high humidity, heavy dews and particularly frequent afternoon and evening rains.
Gray leaf spot symptoms on St. Augustinegrass. Photo credit: UF/IFAS Extension
The individual spots or lesions are first seen as tiny brownish spots smaller than a pinhead. As they become larger, they will be circular and then begin to elongate lengthwise along the leaf. The spots will become brown to grayish in appearance. Numerous spots or lesions may be found on an individual leaf. Heavily infected leaves begin to turn brown and wither, usually beginning at the tip of the blade.
Gray leaf spot can move rapidly during prolonged warm, wet periods. Over watering or irrigating in the evening provides the prolonged period of wetness required for disease infection. For more information on how to correctly water a Florida lawn, visit the UF / IFAS Lawn Watering Website.
According to the Florida Lawn Handbook, “Severity of the disease is enhanced by application of readily available nitrogen fertilizer and is proportional to the amount of nitrogen applied.” Select fertilizers that are low in nitrogen or that have slow release nitrogen. Be careful to not overdo it in fertilizing your lawn and do not apply a high nitrogen fertilizer on top of an already infected lawn. Also, some lawn weed killers such as atrazine will increase the susceptibility of the grass to gray leaf spot.
Irrigate during early morning hours to minimize the period in which the grass is wet and water only on an as needed basis, watering less often but deeply. Avoid frequent, shallow watering and don’t irrigate when the lawn is already wet from rain. With the recent frequent rains, very little to no supplemental irrigation has been needed on most lawns in our area. Avoid leaving irrigation timers on when adequate rainfall has occurred. It’s best to operate irrigation controllers on manual so that the lawn can be monitored and irrigation provided during dry times.
If the disease outbreak is severe, fungicide may be needed. Look for products containing propiconazole, triadimefon or thiophanate-methyl. Always follow the product’s label directions and precautions.
For more information on maintaining a Florida lawn, contact your County UF/IFAS Extension Office or visit the YourFloridaLawn Website.
by Julie McConnell | Jul 22, 2013
When you contact your local extension office for pest control recommendations you will likely hear “follow the label” over and over again. So, why do we emphasize the pesticide label so strongly when talking to both homeowners and landscape professionals?
There are many important reasons why you should always read and follow label instructions.
- The Label is the Law – using a pesticide in a manner that is inconsistent with the label is a violation of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Using a product inconsistent with the label includes, but is not limited to: rate of application, use on site not labeled for control, use on plants/lawns not labeled, frequency of application, method of application, distance from water sources, etc.
- Safety of Humans – using a product incorrectly can cause harm or even lead to death
- Safety to Non-target Organisms – this includes non-target insects, reptiles, birds, fish, mammals, and plants which can lead to negative impact on environment and economy
- Effectiveness of Product – millions of dollars are spent to figure out the most effective way a product works best, follow their instructions! (remember the manufacturer wants the product to be effective so that you’ll recommend to others and buy it again)
- Increased Resistance Decreases Control – improper application and a failure to rotate products as part of an integrated pest management program can increase likelihood of resistant pest populations
Before shopping for any pesticides, do some research:
- Has the pest been identified properly? What life cycle stage is the pest at? Most pesticides have different levels of efficacy depending on life cycle of target. For example, glyphosate works best on young plants that have not yet flowered. Your local extension office can help with identification and timing of control methods
- Can you control the pest with cultural practices such dethatching, irrigation, fertilizer, or mowing height changes? Start with the least toxic method of control and only work up if ineffective
- Read the label before you buy to be sure that it is labeled for your plant /lawn, target pest. The label will also tell you what equipment you’ll need to mix and apply and safety equipment. If product is not ready to use, be sure you can follow mixing and application procedures safely
- Are there particular environmental precautionary statements that are relevant to your site?
- How much do you need? Have you measured the area for treatment? Just as you don’t want to make multiple trips to the store, you also do not want a lot of excess chemicals on hand. They have to be stored or disposed of according to label instructions, too
For more information about pesticide labels read EDIS PI-34 Interpreting Pesticide Label Wording.
