by Pat Williams | Sep 9, 2021
As homeowners, we do value our trees and no one wants to lose a shade tree especially on the house’s south side in Florida. On a recent site visit, a hickory tree had multiple concerns. Upon closer inspection, the tree had a bacterial infection about 30” off the ground with a smelly, black-brown ooze seeping forth. The leaf canopy was riddled with beetle holes and leaf margins were chewed by caterpillars. When leaves were viewed under the microscope, thrips (insects) and spider mites were found running around. The biggest homeowner cosmetic concern arose from hickory anthracnose (fungus) and upon closer inspection found the leaves to have hickory midge fly galls. The obvious question is should the tree come down? I’ll have you read the whole article before giving you the answer.
Each hickory gall is approximately 3/16″ wide.
Hickory anthracnose or leaf spot as seen in the banner photo is caused by a fungal infection during the wet summer months in Florida. The homeowner can usually recognize the disease by the large reddish brown spots on the upper leaf surface (sending a sample to the NFREC Plant Pathology Lab will confirm the diagnosis) and brownish spots with no formal shape on the bottom. Be sure to rake and remove all leaves to prevent your disease from overwintering close to the tree thus reducing infection next year.
A hickory gall has been cut in half to show the leaf tissue.
The fungus can be lessened by good cultural practices and appropriate fungicidal applications. Please remember it is best left to professionals when spraying a large tree. This alone is not cause to remove your tree.
Hickory gall is caused by the hickory midge fly, an insect that lays eggs in the leaf tissue. The plant responds by building up tissue around each egg almost like the oyster when forming a pearl.
As the gall tissue grows, eggs hatch and larva start to feed on this tissue. The larva will continue to
The larva has eaten all soft material inside the gall and is ready to pupate.
feed until it is ready to pupate within the gall. After forming a pupa, the midge fly will eventually emerge as an adult and females will continue to lay eggs on other leaves. The galls are more of a cosmetic damage and because your hickory leaves will fall from the tree as winter comes, the galls will normally not cause enough damage to worry about each year. Once again good cultural practices and disposal of each year’s leaves will reduce the gall numbers next year.
In a large tree with many leaves, foliar feeding by beetles and caterpillars do cause damage though the leaves will still produce enough food (photosynthesis) to keep the tree alive. Most of us never climb our trees to look at leaves to see the small insects/mites and there are more than enough leaves to maintain tree health.
The biggest concern during my site visit was their tree’s bacterial infection. A knife blade was pushed into the wound area and went in less than 1/4″. The homeowner was instructed to look at bactericide applications. In the end, this hickory tree with so many problems is still shading the home and helping cool the house. It is still giving refuge to wildlife and beneficial insects. When in doubt give our trees the benefit and keep them in place. Remember your local Extension agent is set up to make site visits and saving a tree is time well spent.
by Ray Bodrey | Sep 9, 2021
Growing Key Limes in the home landscape is not only a fun and unique addition, but is also delicious – any way you slice them.
The key lime, Citrus aurantifolia, originated in southeast Asia. Genetically speaking, the key lime is likely a tri-hybrid cross between the “odd ball fruits”, known as citron, pummelo and a microcitrus species, Citrus micrantha. There is little commercial key lime production nowadays in Florida, but the fruit remains a very popular landscape option.
The key lime is a small, bushy tree that makes harvest and pruning a breeze. Like most citrus, it’s self-pollinating. The key lime is also an ever-bearing fruit, so there is no real seasonal harvest. The tree could technically bloom any month of the year. There are very few varieties, as trees mostly come from true seed or air layering.
Key Lime fruit at various degrees of ripeness. Photo courtesy of Ray Bodrey, UF/IFAS Extension Gulf County.
Climate is an important factor when deciding to plant a key lime. They are sensitive to cold temperatures, especially below freezing. For the Panhandle, it’s wise to keep key lime trees as patio citrus. In other words, keep the trees in pots so that they can be moved indoors for protection during the winter months. In the ground, trees should be planted in an area where there is a significant wind block. Once a few years have passed and tree has become more mature and acclimated to the environment, they may be able to survive on their own, though it is recommended to cover the tree under sub-freezing temperatures. However, it is important to remember that sunlight is a catalyst for citrus fruit production, be sure to plant the tree in an area with full sun.
The usual suspects of citrus insect pests apply to the key lime also. Citrus leaf miner and mites are the most common culprits. Horticultural and insecticidal oils will certainly help to combat these threats. For planting, key lime is well adapted to a variety of soil conditions in Florida. Be sure to water newly planted trees every other day for the first week and then one to two times a week for the first couple of months. Water periodically after that, making sure the soil doesn’t stay completely dry for long periods. A 6-6-6 fertilizer works great for the key lime. Please follow the fertilizer schedule found in the UF/IFAS EDIS publication, “Citrus Culture in the Home Landscape” by Robert E. Rouse and Mongi Zekri: https://edis.ifas.ufl.edu/pdf/HS/HS132/HS132-11822781.pdf
A final interesting thing about the key lime is the ripening stages of the fruit. Because key limes are ever-bearers, blooms can develop at sometimes widely varying times. This causes an uneven development of fruit across the tree. Be sure to wait until the fruit turns begins to turn yellow before harvest. That’s when it’s mature to eat! Fruit can be stored for up to a week in the fridge or can be juiced and stored in the freezer for later use.
Please contact your local county Extension office for more information. Happy Gardening!
Information for this article can be found in the UF/IFAS EDIS publication, “Key Lime Growing in the Florida Home Landscape” by Jonathan H. Crane: https://edis.ifas.ufl.edu/publication/CH092
UF/IFAS Extension is an Equal Opportunity Institution.
by Sheila Dunning | Aug 26, 2021
Photos by Sheila Dunning
The showy chaste tree makes an attractive specimen as the centerpiece of your landscape bed or in a large container on the deck. Much more of them are being seen since the Florida Department of Transportation has recognized the tree as a desirable median planting. Easy-to-grow, drought resistant, and attractive to butterflies and bees, Vitex agnus-castus is a multi-stemmed small tree with fragrant, upwardly-pointing lavender blooms and gray-green foliage. The chaste tree’s palmately divided leaves resemble those of the marijuana (Cannabis sativa) plant; its flowers can be mistaken for butterfly bush (Buddleia sp.); and the dry, darkened drupes can be used for seasoning, similar to black pepper, making it a conversation piece for those unfamiliar with the tree.
Vitex , with its sage-scented leaves that were once believed to have a sedative effect, has the common name “Chastetree” since Athenian women used the leaves in their beds to keep themselves chaste during the feasts of Ceres, a Roman festival held on April 12. In modern times, the tree is more often planted where beekeepers visit in order to promote excellent honey production or simply included in the landscape for the enjoyment of its showy, summer display of violet panicles.
Chaste tree is native to woodlands and dry areas of southern Europe and western Asia. It will thrive in almost any soil that has good drainage, prefers full sun or light shade, and can even tolerate moderate salt air. Vitex is a sprawling plant that grows 10-20 feet high and wide, that looks best unpruned. If pruning is desired to control the size, it should be done in the winter, since it is a deciduous tree and the blooms form on new wood. The chaste tree can take care of itself, but can be pushed to faster growth with light applications of fertilizer in spring and early summer and by mulching around the plant. There are no pests of major concern associated with this species, but, root rot can cause decline in soils that are kept too moist.
by Stephen Greer | Aug 11, 2021
One big goal of establishing a home lawn and landscape is to enjoy an attractive setting for family and friends, while also helping manage healthy soils and plants. Soil compaction at these sites can cause multiple problems for quality plants establishment and growth. Soil is an incredibly important resource creating the foundation for plants and water absorption.
Photo courtesy: Stephen Greer, UF IFAS
Soils are composed of many different things, including minerals. In Florida, these minerals often include sand of differing sizes and clay in the northern area of the counties in the panhandle of Florida. Soil is also composed of organic matter, nutrients, microorganisms and others. When soil compacts, the air spaces between the sand or clay are compressed, reducing the space between the mineral particles. This can occur anytime during the landscape and lawn construction phase or during long term maintenance of the area with equipment that could include tractors, mowers, and trucks.
What can be done to reduce soil compaction? There are steps that can be taken to help reduce this serious situation. Make a plan on how to best approach a given land area with the equipment needed to accomplish the landscape of your dreams. Where should heavy equipment travel and how much impact they will have to the soils, trees, and other plants already existing and others to be planted? At times heavy plywood may be needed to distribute the tire weight load over a larger area, reducing soil compaction by a tire directly on the soil. Once the big equipment use is complete, look at ways to reduce the areas that were compacted. Incorporating organic matter such as compost, pine bark, mulch, and others by tilling the soil and mixing it with the existing soil can help. Anytime the soil provides improved air space, root will better grow and penetrate larger areas of the soil and plants will be healthier.
Even light foot traffic over the same area over and over will slowly compact soils. Take a look at golf course at the end of cart paths or during a tournament with people walking over the same areas. The grass is damaged from the leaves at the surface to the roots below. Plugging these areas or possibly tilling and reestablishing these sites to reduce the compacted soils may be necessary.
Photo courtesy: Stephen Greer, UF IFAS
Water absorption is another area to plan for, as heavy rains do occur in Florida. Having landscapes and lawns that are properly managed allow increased water infiltration into the soil is critically important. Water runoff from the site is reduced or at least slowed to allow the nutrient from fertilizers used for the plant to have more time to be absorbed into the soil and taken up by the plants. This reduces the opportunity for nitrogen, phosphorus, and other nutrients to enter water areas such as ponds, creeks, lagoons, rivers and bays. Even if you are miles from an open water source, movement of water runoff can enter ditches and work their way to these open water areas, ultimately impacting drinking water, wildlife, and unwanted aquatic plant growth.
Plan ahead and talk with experts that can help with developing a plan. Contact your local Extension office for assistance!
by Ray Bodrey | Jul 29, 2021
Need tips on planting and caring for trees? The primary focus in care of your newly planted tree is root development. It takes several months for roots to establish and newly planted trees and shrubs do not have a very strong root system. Start by digging the hole in a popcorn bowl shape. Once planted, backfill around the root system, but be careful not to compact the soil as this will hinder root growth. Be sure to keep the topmost area of the root ball exposed, about one to two inches. A layer of mulch will be applied here.
Frequent watering is much needed, especially if you are planting in the summer. Water thoroughly, so that water percolates below the root system. Shallow watering promotes surface root growth, which will make the plant more susceptible to stress during a drought. Concentrate some of the water in a diameter pattern a few feet from the trunk. This will cause the root system to grow towards the water, and thus better establish the root system and anchor the tree.
Figure: A Traditional Staking Option. Credit: Edward F. Gilman, UF/IFAS Extension.
Mulch is important in the conservation of soil moisture. Pine needles, bark, wood chips, and other organic materials make a great mulch. A three inch layer of mulch will usually suffice. It’s important to keep the mulch a few inches from the trunk as mulching too close to the tree trunk can cause rot.
You should always prune the bare roots of trees during planting. These exposed roots in containers can be damaged in shipping and removing some of the roots will help trigger growth. Pruning some of the top foliage can also reduce the amount of water needed for the plant to establish, as well. Trees and shrubs grown and shipped in burlap or containers usually need very little pruning.
Newly planted trees often have a difficult time establishing if the root system cannot be held in place. Strong winds and rain can cause the plant to tip over. Avoid this by staking the plant for temporary support. A good rule of thumb to determine staking need is if the trunk diameter measures three inches or less, it probably needs some support! Tie the stake to the plant every six inches from the top. However, only tie the trunk at one spot. Don’t tie too tightly so that the tree has no flexibility. This will stunt the growth of the tree.
Following these tips will help ensure your tree becomes well established in your landscape. For more information please contact your local county extension office.
Information for this article can be found in the UF/IFAS EDIS publication: “Planting and Establishing Trees” by Edward F. Gilman and Laura Sadowiski: https://edis.ifas.ufl.edu/pdf%5CEP%5CEP31400.pdf
Supporting information also provided by UF/IFAS Extension Forestry Specialist Dr. Patrick Minogue, of the North Florida Research Education Center in Quincy, Florida.
by Larry Williams | Jul 15, 2021
Q. One of my two fig trees has produced a few figs. The other one, which is the largest and healthiest tree, has never had a fig on it. Both where planted six years ago. Why is it not producing?
Mature fig tree with fruit. Photo credit: Larry Williams
A. It may be a matter of age and being overly vigorous. When a fruit tree is younger, it puts most of its energy into producing leaves and shoots. Until the plant becomes mature and slows down in the production of leaves and shoots, it will produce few to no fruit. It may take a year or two more for your tree to slowly and gradually switch from producing mostly leaves and shoots to producing and maturing some fruit. Patience is needed.
Be careful to not overdo it in fertilizing and/or pruning your fig tree. Too much fertilizer, especially nitrogen, or severely pruning the tree will result in the tree becoming overly vigorous at the expense of setting and maturing fruit. This includes fertilizer that the tree may pull up from a nearby lawn area. A tree’s roots will grow outward two to three times beyond its branch spread into adjacent lawn areas.
The end result of being heavy handed with fertilizing and/or overdoing it in pruning is the same – it forces the plant to become overly vigorous in producing leaves and shoots at the expense of producing and maturing fruit.
In addition, the following is taken from an Extension publication on figs and includes the most common reasons for lack of fruiting, in order of importance.
- Young, vigorous plants and over-fertilized plants will often produce fruit that drops off before maturing. If plants are excessively vigorous, stop fertilizing them. Quite often, three of four years may pass before the plant matures a crop because figs have a long juvenile period before producing edible quality fruit.
- Dry, hot periods that occur before ripening can cause poor fruit quality. If this is the case, mulching and supplemental watering during dry spells will reduce the problem.
- The variety Celeste will often drop fruit prematurely in hot weather regardless of the quality of plant care. However, it is still a good variety to grow.
- An infestation of root-knot nematodes can intensify the problem when conditions are as described in item 2.
- You could have a fig tree that requires cross-pollination by a special wasp. This is a rare problem. If this is the case, then it will never set a good crop. The best way to resolve this is to replace the plant with a rooted shoot of a neighbor’s plant you know produces a good crop each year.
