Best to Plant Trees and Shrubs in Fall

Roots rarely rest. While leaves turn colors in the fall and litter the lawn in the winter, roots keep on growing. But roots can use a little help.

The best thing to do for roots is to plant them in a big hole in the fall.

Tree studies have shown that when planted in loose, well-drained soil, the roots of certain trees spread as much as 14 feet beyond the original root ball within three years.

roots exposed

Roots on live oak can grow 8 feet in every direction in the first year after planting.

Improving the structure of the soil by loosening the soil over a large area provides a good environment for roots to grow.

Studies also have shown the futility of adding peat moss, other organic matter, and fertilizer to the planting hole. Fifty percent of the roots were outside of the planting hole within twelve months of planting anyway and no longer reaping any “benefits” that might have been obtained by amending the planting hole. The lesson learned is to not encourage roots of trees and shrubs to stay in the planting hole by adding fertilizer and soil amendments. Doing so can delay root growth outside of the “goodies” placed in the planting hole. It is somewhat like taking the tree or shrub out of a container and placing it back in a “container” in the ground. Genetically, tree and shrub roots “want to” grow outward into surrounding soil quickly. But creating a little “container” with peat moss and fertilizer can be counterproductive, causing the roots to more slowly grow outward into the surrounding soil.

So, don’t encourage roots of newly planted trees and shrubs to stay in the planting hole by adding fertilizer and soil amendments. But do plant in the fall.

The key is that roots don’t go dormant. They continue to grow and develop throughout the cooler fall and winter months. And because the top grow slows down during fall and winter, there is less demand on the roots.

Fall-planted ornamentals normally have a supply of carbohydrates stored in their roots from the past growing season. So, with little demand from the tops, the roots are able to grow and become well established before the next spring. When spring does come, fall planted trees and shrubs are ready to grow and are better established as compared to spring planted trees and shrubs.

Take advantage of cooler fall temperatures, save money on soil amendments, and give your trees and shrubs a head start. It’s a win, win, win!

Fall Preparation in the Garden!

Fall Preparation in the Garden!

Carrots need enough space so as not to compete for light, nutrients, or moisture. Photo by Full Earth Farm.

Photo by Full Earth Farm.

Yes, that’s right! We made it through the hottest part of the year and we are looking ahead to fall just around the corner!  I am excited to be discussing September and what we can do to prepare for fall in the garden.  As the nighttime temperatures start to cool down, we are given many more options.

For annual color plantings in September, try Ageratum, Celosia, Zinnias, and Wax Begonia to add fall color to your landscape.  Bulbs will also add color, texture, and pattern to a bed.   If you have some extra space, a variety of elephant ears could really accent a bed or you could always go with the classic calla, narcissus or zephyr lily.  Popular vegetables to plant in North Florida in September are broccoli, carrot, cabbage, and collards. See Vegetable Gardening in Florida This is also the time of year to establish strawberry plants.  Some great herbs to get started are Mexican tarragon, mint, rosemary, and basil.

Strawberries growing on "plastic" to protect them from water splashed fungal spores found in soil. Image Credit: Matthew Orwat UF/IFAS Extension Washington County

Image Credit: Matthew Orwat UF/IFAS Extension Washington County

There are many things that can be done in your lawn during September.  Monitoring your lawn for its health and potential insect pests is important this time of year.  Common insects to scout for are fall armyworms, chinch bugs, mole crickets, and sod webworms.  The last fertilizer application should be done by the middle to end of September.  Make sure you choose a fertilizer with little to no phosphorus unless a soil test shows differently.  To maintain a healthy lawn, avoid weed and feed products and only apply herbicides in areas with high infestations of weeds. Weed and feed products are not recommended because the timing of when to fertilize and the timing of the weed killer is not always the same. The best management practice is to use a separate treatment for weeds and when possible spot treat weeds.

If you already have bulbs in your landscape from previous growing seasons, this is the time to divide and replant those that are big.  You can also add organic matter to new planting areas. Continue working on your vegetable plants and prepare them for either transplants for a fast start, or plants seeds for more variety.  Throughout your landscape, it is important that plants are getting the right amount of water as we go in and out of wet and dry weather this time of year.

October will be here before we know it in just a couple of weeks. Look out for the next article to come.  We will be getting into the cooler nights and more options for planting vegetables and herbs!

Plant Growth Abnormalities

Plant Growth Abnormalities

Every so often while I am enjoying a walk through the garden, I notice a growth pattern on a plant that is just not normal.  One of the more interesting patterns I see is called fasciation.  This is a distortion of plant tissue that often causes flattened, curved, or the thinning of plant tissues.  I recently noticed this on the stem of a Coral Porterweed in the Escambia County Demonstration Garden.  The leaves were a normal shape but several inches of the stem were flattened and curved.

The distorted stem tissue of a Coral porterweed. Photo by Beth Bolles, UF IFAS Extension Escambia County.

So what is causing this type of growth pattern?

The most common cause of fasciation is usually some type of genetic mutation in the growing points of the plant.  The other possible causes could be a physical injury to new tissues, a bacterial infection, chemical injury, or even an insect injury.  Fasciation will be random in its occurrence and many gardeners may never have it occur on a plant in their yard. I have seen it on both woody and herbaceous plants in my own yard and in the demonstration gardens.

If you see a plant exhibiting this distortion of growth, you don’t need to take any action.  If the growth is unsightly to you, prune out the affected plant tissue.  It is probably best that you not propagate material from an affected plant just to prevent any transfer of the distortion to a new plant if the cause is genetic or from a living organism.

Hickory Gall and Anthracnose, a Deadly Combination?

Hickory Gall and Anthracnose, a Deadly Combination?

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.

Whole Hickory Gall

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.

Gall Half

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

Gall Larva

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.

 

Timing is Everything when Controlling Lawn Weeds

Timing is Everything when Controlling Lawn Weeds

Hot, summer months are not the time to be using most lawn herbicides.

One issue is the heat of summer. Most lawn herbicide labels include statements such as the following.

“Do not apply when temperature exceeds 90°F.” “Do not broadcast apply this product when air temperatures are above 90°F (85°F for St. Augustinegrass) unless temporary turf injury can be tolerated.”

Every year we’ll see lawns that are injured or killed because of lawn herbicides being applied when temperatures are too hot.

Summer is usually a rainy and windy time of the year. Many lawn herbicide labels include statements such as the following.

“Allow 12 hours after application before watering lawn for maximum effectives on listed weeds.” “Apply only when wind is no more than 10 mph.” “Applying this product in calm weather when rain is not predicted for the next 24 hours will help to ensure that wind or rain does not blow or wash pesticide off the treatment area.”

It is critical to read and follow the label directions and precautions for any pesticide you use. Pesticide labels, including herbicides, include the following statements.

“To the extent consistent with applicable law, the buyer assumes all risks of use, storage, or handling of this product not in accordance with label directions.” “It is a violation of Federal law to use this product in a manner inconsistent with its labeling.”

Crabgrass plant growing in centipedegrass lawn

Crabgrass growing in centipedegrass lawn. Photo credit: UF/IFAS Extension

By the time summer arrives, many of the lawn weeds are mature, which means they are well established with extensive root systems. These mature, well established weeds are much more difficult to control. They are more susceptible to herbicides when they are small, young, and not well established. Also, these mature weeds have been allowed to produce countless numbers of seeds as they move into summer. Most weeds are prolific seed producers. For example, a single crabgrass plant (a common summer lawn weed) can produce 150,000 seeds.

Applying a preemergence lawn herbicide in February to help prevent summer annual weeds such as crabgrass or applying a postemergence lawn herbicide during spring while the weather is mild and before the weeds are out of control simply makes more sense than waiting until summer.

The best options now with lawn weed control involve continuing to follow good mowing practices, maybe hand removal of some weeds, and just simply waiting it out until next February and spring to worry with the use of lawn herbicides.

In the meantime, you may want to read the following UF/IFAS Extension publication on lawn weed control.

https://edis.ifas.ufl.edu/pdf/EP/EP14100.pdf

Larry Williams, UF/IFAS

Centipedegrass Weed Control:  You Only Need 3 Herbicides!

Centipedegrass Weed Control: You Only Need 3 Herbicides!

Nearly everyone likes turfgrass lawns.  They’re pretty and green.  They filter water, chemicals, and nutrients before they enter our groundwater systems.  They provide a recreation spot for people and pets.  But lawns also come with maintenance tasks, one of which is weed control.  Fortunately, keeping our common Centipedegrass lawns relatively weed free is as simple as smart management and utilizing herbicides effectively.  Though the number of herbicides available for purchase can be overwhelming, you only need three to keep weeds at bay – a selective grass herbicide, a strong broadleaf herbicide, and a sedge herbicide!

Dollarweed in flower

Dollarweed, one of the toughest broadleaf weeds for homeowners to control. Picture courtesy of  Julie McConnell, UF/IFAS.

First up on the essential herbicide list is the selective grass herbicide Sethoxydim.  While most folks’ weed focus is centered on broadleaf weeds, grassy weeds like Crabgrass, Bahiagrass, Goosegrass, and others can be just as problematic and make for a very unsightly lawn.  Enter Sethoxydim.  Cheap and easy to find, Sethoxydim is offered as the active ingredient in many branded products like Fertilome Over the Top Grass Killer, Hi-Yield Grass Killer, and many more.  These products control weedy grass species without seriously harming Centipedegrass or broadleaf ornamental trees and shrubs (Centipedegrass may temporarily be yellowed after sethoxydim application but will recover).  Not only will it kill out the unwanted grass growing in your Centipede, but it will also remove these weeds from your flower beds!

Second, having a strong broadleaf herbicide on hand is necessary.  I say “strong” because many of the homeowner grade products available at garden centers simply don’t have the “juice” to control tough broadleaf weeds like Dollarweed, Doveweed, Virginia Buttonweed, and others.  For this job, I prefer to use a commercial grade 3-way product like Celsius WG by Bayer.  Celsius WG is a 3-way combination herbicide with a healthy dose of Dicamba as its primary ingredient.  Though Dicamba is a notoriously volatile chemical known to cause damage to unintended plants through drift in hot weather, combining it with the two other products in Celsius WG makes it safe to use in lawns, even in the heat of summer.  While strong broadleaf herbicides like Celsius WG are expensive on the front end, don’t let that deter you.  These products wind up being very cost effective in the long run due to minute mixing rates (one bottle goes a very long way in most residential lawns) and effectiveness – you simply will not need to waste time and money spraying lawn weeds over and over to obtain control like is necessary with lesser products – one or two applications will solve the toughest broadleaf weed problems.

Finally, any good lawn weed control program will include a quality sedge control herbicide.  Sedges (often called “nutgrass”) look like grasses but are a completely different category of plants and as such, require specialized herbicide chemistries to achieve control.  Sedge weeds prefer wetter areas of lawns, though they can occur in pretty much any lawn site and are very unsightly.  For this weed category, there are several options available to homeowners.  The one that consistently provides the best control in lawns is Halosulfuron-methyl, the active ingredient in the aptly named product Sedgehammer.  Conveniently coming in individually pre-mixed packets for small lawns or a larger bottle when more acreage is to be treated, Sedgehammer couldn’t be easier to mix and use. While Sedgehammer and similar products are extremely effective in controlling various sedge weeds, they tend to work very slowly, and patience is required.  Weeds immediately stop growing following a Sedgehammer application, but it can take up to three weeks to notice the sedges dying.

While having and using the above three herbicides can control almost any weed homeowners may encounter in their lawns, it is important to remember that herbicides are not substitutes for proper lawn management.  When good cultural practices in lawns are followed, such as mowing at the correct height, only watering when necessary, following UF/IFAS fertilizer recommendations, etc., chemical weed control may not even be necessary in many cases!  Also, once the decision to purchase and use chemical herbicides has been made, it is critical that one always read the label before using any herbicide product.  This ensures safe and effective use of the product; the label is literally the law!

For assistance in choosing the correct herbicide for your lawn and other lawn care concerns, contact your local UF/IFAS Extension Office!  Happy Gardening!