by Larry Williams | Feb 17, 2015
Diseased Turfgrass – Image Credit Matthew Orwat
With a few nice late winter days, many people get a good dose of spring fever. But be careful when the fever hits you. Don’t fertilize your lawn too early. The fever may turn into a lawn “headache”.
Wait to fertilize. Fertilizing while the soil is too cool can result in nutrient deficiencies such as iron deficiency causing yellow areas in the lawn. Fertilizing early can result in injury to a lawn’s roots from fertilizer burn. Or tender growth promoted by an early fertilizer application may be injured by a late frost or freeze. Have patience, allow the lawn to green up on its own and then fertilize, even if it’s not until mid April or May.
Get the numbers right. Our lawns need almost the same amount of potassium as compared to nitrogen. Getting this right can make a difference in the long-term health of your lawn. Look for a lawn fertilizer with an analysis such as 8-0-8, 10-0-10, 15-0-15, 18-0-18, 15-2-15, 16-0-8, etc. Look for a fertilizer with a 1:1 ratio of nitrogen to potassium. These numbers provide the buyer important information. The first number is the percent nitrogen (N), the second number is the percent phosphorus (P) and the third number is the percent potassium (K). Adequate potassium has been linked to reduced disease problems, drought and cold tolerance and enhanced root growth.
Use low phosphorus. Lawn grasses use much less phosphorus than nitrogen or potassium. Because of this and because phosphorus has been implicated as a cause for problems in our surface waters, it’s recommended to base phosphorus rates on the results of a reliable soil test. In absence of soil test results, select a fertilizer with 2% or less phosphorus such as 15-2-15, 8-0-8, 16-0-8, etc. It’s best to base P applications on the results of a reliable soil test.
Don’t fertilize too late. The latest month to fertilize our warm season lawn grasses in North Florida as recommended by University of Florida turfgrass researchers is mid September. If you have centipedegrass, it’s recommended to fertilize no later than July.
Measure your lawn. Most homeowners apply too much fertilizer because they do not know the square footage of their lawn. Measure the size of your lawn (front, back and side yard) and err on the side of using less fertilizer than recommended.
by Larry Williams | Jan 27, 2015
Do you have camellia plants with flower buds that fail to open? Here are possible causes for this problem.
For more information on camellias, contact the UF/IFAS Extension Office in your County or visit http://edis.ifas.ufl.edu/ep002 to access the publication, “Camellias at a Glance.”
by Larry Williams | Dec 9, 2014
From about mid November or December to March, deciduous trees have little to no foliage making us more aware of their shapes, forms and barks.
Here are a few trees to consider for adding winter appeal to your landscape.
Gary Knox, UF/IFAS Horticulturist, describes the crapemyrtle’s winter interest perfectly in his publication, “Crapemyrtle in Florida.” Knox writes, “When the leaves fall in winter, the crape myrtle becomes a living sculpture. The trunk and branches of tree-form plants have an attractively gnarled, sinuous character with smooth bark. Strips of bark peel off (exfoliate) in early summer to reveal mottled new bark ranging in color from pale cream to dark cinnamon to rich brown to bright orange.”
Here are some recommendations for crapemyrtles with attractive bark. ‘Acoma’ is an outstanding semi-dwarf hybrid reaching a mature height of 10 to 15 feet that has creamy beige bark and snow white flowers. ‘Apalachee’ is another outstanding selection with cinnamon orange bark and light lavender flowers. Its mature height is about 20 feet. The cultivar ‘Osage’ produces dark orange bark and medium pink flowers with a 20-foot mature height. ‘Fantasy’ is a large maturing variety growing to more than 20 feet tall with outstanding red orange bark and white flowers. More cultivars are listed in Knox’s publication available at http://edis.ifas.ufl.edu/MG266.
River birch is another tree with unusual papery peeling bark. The cultivar ‘Heritage’ is the closest to a paper white birch that will tolerate our hot summers. Expect a river birch to reach 40 to 50 feet in height and 25 to 35 feet in width.
Cultivars of Ulmus parvifo
Apalachee Crapemyrtle Bark Photo Credit: UF/IFAS
Drake Elm Bark Photo Credit: UF/IFAS
lia, Chinese elm, provide winter interest. “The showy, exfoliating bark reveals random mottled patterns of gray, green, orange and brown, adding great textural and visual interest, especially to its winter silhouette,” writes Ed Gilman, UF/IFAS Horticulturist, in his factsheet on Chinese Elm. This and other tree factsheets are available at http://hort.ifas.ufl.edu/woody. ‘Drake’ and ‘Allee’ are two popular Chinese elm cultivars. Chinese Elm can reach 80 feet in height but is more often seen at 40 to 50 feet with an equal spread.
American Hophornbeam, Ostrya virginiana, is an underused tree that grows to about 50 feet in height. Its grayish bark peels off in longitudinal strips revealing orange patches underneath.
Acer buergeranum or trident maple is a small, underused and hard to find tree. It usually is seen with multiple stems originating fairly low on the trunk giving the small tree a bushy appearance. It has noticeable orange-brown peeling bark.
by Larry Williams | Nov 11, 2014
As the season changes, plants change as well. This is true in evergreen and deciduous trees and shrubs as well as our lawn grasses.
The cooler night temperatures and the shorter day length of fall result in changes in the physiology of many of our landscape plants and lawn grasses.
It’s common for azaleas to lose a few leaves now. These are the older leaves on the stem near the center of the plant. They turn reddish or yellow and drop from the plant. This is normal from now until spring. However, if the younger leaves, those nearest the tip of the shoot, turn yellow or brown there is cause for concern. Poor drainage, lack of water or alkaline soils may cause this condition.
Yellow leaves may appear on camellias, gardenias, cherry laurel and oleanders. Again, as with azaleas, these are the older leaves on the stem near the center of the plant. It’s normal for these leaves to drop from the plants now until spring. However, do not confuse scale damage on camellias for normal aging of leaves. Scale insects feed on the lower surface of camellia leaves causing them to become splotched with yellow.
Many of the leaves on sycamore trees have changed from green to brown. Although this phenomenon occurs every year, it’s not caused by a change in day length or temperature. This is not a true seasonal change. It’s the result of insects feeding on the leaves. By the time the damage is visible, there is little that can be done to correct the problem. However, the problem will take care of itself since sycamore trees will soon be dropping their leaves.
Lawn grasses also experience some seasonal changes. The growth rate of lawn grasses slows in the fall. Although this slowdown in growth means less mowing is required, it also means that lawns will not be as attractive as they were during spring and summer. Because of this reduced growth rate, grasses cannot produce enough new leaves to replace the leaves that are dying. The end result is a dull, yellow-green lawn.
Normal seasonal color change in centipedegrass lawn from green to reddish purple.
Photo by Larry Williams, Okaloosa County Extension
Normal seasonal color change on older ‘Little Gem’ Magnolia leaves. Photo by Larry Williams, Okaloosa County Extension
Numerous reddish-purple blades throughout the lawn may be visible now as well. Cooler temperatures, injury to the leaf blades from foot traffic, mowing equipment, vehicles, etc, can cause this. It also could be caused by lack of potassium or phosphorus but is more likely the result of cooler temperatures, especially if it did not show up until fall.
by Larry Williams | Oct 14, 2014
Goldenrod are easily recognizable this time of year with its showy yellow flowers held high on stems moving back and forth by autumn winds. A field full of these vivid yellow blossoms is a sight to see with a bright blue fall sky as a background. But too often this plant is blamed for the sneezing, runny nose and itchy eyes that many people suffer while goldenrod is blooming.
The common culprit causing these allergy symptoms is ragweed, not goldenrod.
Ragweed blooms at the same time as goldenrod, August to frost.
Ragweed releases its billions of tiny, lightweight pollen grains into the air this time of year. This windborne pollen causes much of the hay fever problems. Goldenrod pollen is too large and heavy and sticky to be windborne. It relies on insects to carry its pollen. I suppose if you put your nose right up into a cluster of goldenrod flowers and took a big sniff, you might be bothered by the pollen. But otherwise, it is not going to get into your nose.
Goldenrod is an innocent bystander as ragweed remains camouflaged releasing its pollen. Ragweed visually blends in with other green plants. Despite the fact that common ragweed, an annual, can grow three to greater than six feet in height, it just does not get your attention. It is quite common along roadsides, vacant lots and abandoned fields. Its inconspicuous flowers start out as green, similar in color to the leaves, turn a yellowish-green and finally dry to a brown color. They are never showy.
Goldenrod in bloom Photo credit: Larry Williams
Ragweed in bloom Photo Credit: Larry Williams
Enjoy the bright yellow flowers of goldenrod this fall. But please do not blame them for your allergies.
