by Larry Williams | Jun 3, 2014

Glistening webbing formed by tree cattle (psocids) Photo credit: Doug Caldwell, University of Florida
Many people are noticing small insects on trunks and branches of their trees. When disturbed, these insects move in a group and are commonly called tree cattle because of this herding habit. They are ¼ inch brownish-black insects with white markings.
Some people assume that these insects will injure their trees but they are harmless. They could be considered beneficial.
These insects are called psocids (pronounced so-cids). They have numerous common names including tree cattle and bark lice. They feed on lichen, moss, algae, fungi, spores, pollen and the remains of other insects found on the tree’s bark. As a result, they are sometimes referred to as bark cleaners.
Tree cattle may form webbing. This webbing is tight against the tree’s trunk and/or limbs. It appears suddenly. The webbing is used as a protection from weather and predators. Underneath you may find psocids.
The glistening webbing may attract a person’s attention resulting in the tree being visually inspected from top to bottom. A dead branch or other imperfections in the tree may be noticed and then wrongly blamed on the tree cattle. I’ve talked to homeowners that sprayed their trees with insecticides or that hired pest control businesses to treat the trees as a result of finding the webbing/psocids. One person told me that he cut down a tree after finding tree cattle. He wrongly assumed that these insects were pests that might move through the area and kill trees. He thought he was doing a good thing.
Adult female psocids lay eggs in clusters on leaves, branches and tree trunks. After hatching, the immature insects (nymphs) remain together under their silk webbing. Adults have wings which are held roof-like over their body. Nymphs are wingless. Psocids usually have several generations per year in Florida.
After seeing the webbing and/or insects, many people insist on spraying insecticides because they believe these insec

Under the webbing live hundreds of psocids. Photo credit: UF/IFAS Jim Castner
ts are damaging their trees. But as mentioned, they are bark cleaners and do not damage trees. If the silk webbing is considered unsightly, a heavy stream of water from a garden hose can be used to wash insects and webbing off infested trees. If nothing is done, the webbing usually goes away in several weeks.
Psocids can be found on many rough-barked hardwood trees and palms. Occasionally, they may be found on wood siding, fence posts or similar areas.
by Larry Williams | Apr 29, 2014

Kentucky bluegrass, Fescuegrass & ryegrass (annual ryegrass pictured) can be seeded to provide a temporary winter lawn but will not provide a permanent lawn in Florida due to our hot, wet summers. Photo Credit: Dan Culbert, UF/IFAS
If it sounds too good to be true, it probably is. This phrase offers sound advice for the person looking for the “perfect” lawn grass.
It’s common to see advertisements for the perfect lawn grass. You should be skeptical when reading advertisements that proclaim an amazing grass that produces a lush, green lawn with very little care. Question advertisements for grass seed mixtures that grow from Alaska to Florida. Beware of advertisements that do not include a specific name for the lawn grass being sold. Don’t believe advertisements that claim their grass even grows in impossible spots.
A number of years ago, I called a company that was advertising a grass seed mixture in hopes of finding out specifically what grass seeds were in this “too-good-to-be-true” mixture. I was told the seed mixture included Kentucky bluegrass, creeping red fescue and annual ryegrass. This information was not included in the advertisement. And it claimed that it would produce an attractive lawn for Florida.
In Florida, ryegrass, fescuegrass and Kentucky bluegrass will produce a green lawn during winter and early spring. However, as temperatures warm in late spring and summer, these grasses will die. All three are cool-season grasses that will not tolerate our hot, humid summer weather. They will not produce a permanent lawn in our area.
Basically there are seven types of grasses from which to choose when considering planting a lawn in Florida. Centipede and St. Augustine are the most commonly planted in our area. Bahia, bermuda, carpet, seashore paspalum and zoysia are used less often. All of these grasses have advantages and disadvantages, which should be looked at and understood before choosing a grass for your lawn.
With time, most people in our area will become frustrated with their lawn. As a result, North Florida is a great area to market a too-good-to-be-true lawn grass. It’s difficult to grow a lawn here. All of our lawn grasses are native to other parts of the world – they did not exist in our native ecosystem. Expectations for a Florida lawn are too high. Because of these factors, many people are looking for that too-good-to-be-true grass.
Be cautious before spending time and money on one of those “perfect” lawn grasses.
Contact the University of Florida Extension Office in your County or visit the following website for reliable information on lawn grass selection and maintenance for Florida. hort.ufl.edu/yourfloridalawn
by Larry Williams | Apr 1, 2014

Sodding Lawn Photo Credit: UF/IFAS

Hand Raking Lawn Area Photo Credit: UF/IFAS
Cutting corners during lawn renovation usually results in poor turf establishment and long-term lawn maintenance problems.
Occasionally it is necessary to renovate a lawn or replant sections of a lawn. When replanting a lawn, it is best to not cut corners – you’ll usually pay for it in the long run. One of the most important factors is to prepare a good planting bed when renovating a lawn.
It doesn’t matter if you intend to re-sod, re-sprig or reseed; you need a level, loose and well-drained planting site for your lawn. A level lawn is much easier to mow. The loose soil allows for quicker root and runner establishment. Also, a well-drained site allows excess water to drain, preventing some disease problems.
One option is to spray the existing weeds and grass with a glyphosate herbicide such as Roundup. Allow the proper number of days for the weeds and grass to turn yellow (usually seven to 10 days).
Next, thoroughly till the area to a depth of 6 to 8 inches to loosen the soil.
Finally, level and smooth the planting bed, raking and then dragging (if needed) the bed. This can be done with a hand-rake and a hand-pulled drag such as a piece of chain-link fence on smaller areas. A tractor with rake and a grading box can be used on larger areas. A second option is to rent a sod cutter or remove the existing grass with a shovel before tilling and grading the site.
But whatever you do, don’t just lay new sod or broadcast grass seeds over a compacted, uneven, old lawn. There are just too many possibilities of having long-term and costly lawn problems as a result.
For additional information on establishing a Florida lawn, contact your local University of Florida Extension Office or visit http://hort.ufl.edu/yourfloridalawn.
by Larry Williams | Feb 11, 2014

Dormant Peach Tree. Image Credit UF IFAS Environmental Horticulture Department
It is hard to believe with all of this recent cold weather, but now is the time to plant fruit trees in the Florida Panhandle. When planning what type of fruit tree to plant, correct cultivar selection should be the top priority.
The dooryard fruit producer oftentimes finds it difficult to choose the correct fruit cultivar for this area. An inappropriate choice results in disappointment when home gardeners find that they have paid for, planted and cared for fruit trees that are not adapted to the Northwest Florida climate.
Weather is probably the most important factor determining where certain fruits can and cannot be grown.
Most fruits which grow in the northern part of Florida are deciduous, which means that during the winter the trees lose their leaves and go into a period of dormancy, or rest.
During this rest period, the tree must be exposed to chilling temperatures. This exposure to the cold prepares the plant to resume active growth in spring. Temperatures below 45°F accumulated throughout winter determines the total hours of chilling. Species differ in the amount of chilling they need. This is known as a plant’s chilling requirement. Lack of enough chill hours result in sparse foliage and little to no flower production. And if there are no flowers, there will be no fruit.
North Florida receives between 400 to 650 hours below 45°F during the average winter. This provides enough chill hours for a few apple cultivars such as Anna, Ein Shemer, Dorsett Golden, TropicSweet and Shell. However, it does not provide the chill hours required for many of the more common varieties such as Red Delicious and Golden Delicious.
This same environmental factor holds true for most deciduous fruit trees. For example, some of the better known peach cultivars, such as Elberta and Bell of Georgia, perform poorly here following most winters. Both require roughly twice as many chill hours as the Panhandle receives during most winters. There are a few peach cultivars that perform OK in our area.

Blackberry Fruit. Photo Credit: Theresa Friday, Santa Rosa County, UF IFAS Extension
The results of selecting the wrong cultivar is only one of the disappointments experienced by those wishing to grow fruits in North Florida. Even when the correct cultivar is selected, many fruit enthusiasts (people who have dreams of homemade peach cobbler, apple pies, plum jelly, etc.) are disappointed to see insects eating their fruit, diseases causing their fruit to rot or possibly all their fruit falling to the ground before it is ready to be eaten.
In order to be successful with fruit production in North Florida, a person needs to ask a lot of questions before planting the first plant.
- Which cultivars grow well here?
- How much care is needed to grow this type of fruit?
- Do I have the time to devote to pruning, spraying, fertilizing and watering?
If you don’t know the answers to these questions, talk to a knowledgeable employee at a local, reputable nursery, consult the Dooryard Fruit Selection publication, or call your UF IFAS Extension Office before choosing to plant fruit trees this winter.
by Larry Williams | Jan 27, 2014
This week, Northwest Florida is once again receiving some bitter cold temperatures. The freezing weather two weeks ago resulted in some cold damage to some local citrus trees. Cold injured citrus trees can take a while to become evident.

Citrus in freezing weather, under protective microsprinkler irrigation. Image Credit Doug Mayo UF IFAS
What appears to be damage will not always be permanent. Never be in a hurry to remove cold injured tissue from a citrus tree. Citrus, especially Satsuma, can be very resilient and will often re-sprout on injured tissue. Pruning before this can happen can remove fruit producing branches. Leaves on a freeze-damaged citrus tree will be hard and brittle.
If freeze damage is severe, the leaves will collapse, dry out and fall from the tree. It’s normal for leaves to take on a wilted or drooping appearance during periods of low temperatures. Don’t confuse this with freeze damage. Frozen leaves will not be wilted – they will be hard and brittle. Freeze damage can also cause the trunk and larger branches to split and the bark to become loose. Twigs and branches may continue to die for up to two years following a severe freeze.
Unless the soil becomes dry, be careful to not water cold injured citrus trees during warm periods that often follow freezes. This will delay the tree’s growth and keep the tree in a more dormant state. However, it is important to not let citrus trees go totally dry, because this will increase freeze damage. Later on, if you see that the damaged tree is putting on new growth, it’s okay to give it a little water.
It is best to not prune or fertilize citrus trees during fall and winter.Delay pruning of damaged limbs until late spring or summer because it’s difficult to determine the extent of damage until spring growth takes place. Pruning also may encourage new tender growth during the cold season.
If it appears that you’ve lost half the tree in a freeze, you’ll only need to apply about half as much fertilizer. If you have the situation where many leaves were lost but twigs and branches were not injured, you’ll need to slightly increase the amount of fertilizer. Fertilization should begin after new growth has occurred come spring. It’s a good idea to make frequent light applications rather than one heavy application.
Fertilizing your lawn during fall and winter may not only be damaging to your lawn but it can potentially cause cold injury to your citrus trees, as well. The roots on trees (including citrus) extend two to three times beyond the tree’s branches. As a result, citrus tree roots grow out into the lawn. Tree roots in the lawn are shallow. So, late applications of lawn fertilizer will impact your citrus trees as well. Your lawn and citrus needs ample time to use the fertilizer but yet still have time to go dormant before cold weather arrives.