A Primer on Pruning

A Primer on Pruning

Pruning is a much needed yet often misunderstood practice. This is perfectly understandable as most people look at a tree and wonder which branches need to be cut, why they need to be cut, and what time of year is appropriate to do so. Confusion is understandable, but a better grasp on a few key concepts will clear everything up.

Structure

Red Maple
Red Maple structure IFAS Photo: Hassing, G.

Before you begin to look into anything else, it is important to understand the structure of a tree. For the purposes of pruning, we’ll focus on roots, and stems. The roots of a tree anchor it to the ground providing water and nutrition to the main stems of the tree. Roots and stems in any plant are a delicate balance. Cutting stem tissue will affect roots so don’t remove too much in a single session. A good rule of thumb is to not take more than 1/3 of the stem tissue present. The next concept is the natural shape of the tree you want to trim. Most have one dominant leader with supporting branches forming the canopy. In these cases, remove competing leaders to keep the canopy full and well-shaped. Other trees such as crape myrtle (Lagerstroemia indica) are multi-stemmed with 2-3 codominant leaders. Prune away any challengers to your main leaders while keeping the “vase” shape for which these trees are known. With this in mind, it’s time to decide which stems to remove.  

What to Cut

Safety and tree health are the focus as a homeowner decides which stems need pruning. When a branch is to be removed, make your cut It is important to keep the branch collar in mind when making your cuts. This collar is denoted as a ring of tissue at the connection of branch and trunk. Cut as closely as possible without disrupting this tissue. Any dead, diseased, and damaged branches are the first needing cut. They take resources from the healthy branches and are unsightly. Next, look for any crossing limbs. These scrape against one another as the wind blows and risk destroying bark tissue making the tree susceptible to disease. Focus next on structural issues or tree shape. Remove challenges to the leaders as outlined in the previous paragraph. Safety concerns will be your next focus. Look for bark inclusions which are weak connections indicated with a “V” shaped fork between limbs which may fail in high wind. If found, consult a certified arborist as pruning may not be your only option. Finally, eliminate lower limbs impeding walkways and any drooping from their own weight. This is also when species specific pruning is prudent to promote flowering or fruiting.  

Branch collar
Branch collar example IFAS photo: Gilman E., Bisson A.

When to Cut

Now that we know what to prune, when is it prudent to do so? This cycle will vary based on quality of stock from the nursery, age of the tree, growth rate, and how prone they are to decay. In Florida, this is on average every three years. Keep in mind the “May rule” when considering what time of year to prune. Any plant blooming prior to May should be pruned once flowering has ceased, but no later than July. Any plant blooming after May should be pruned around February or March at the latest.

Bark inclusions
Examples of bark inclusions IFAS Photo: Gilman, E., Bisson A.

Pruning is an important practice for keeping your trees healthy and ensuring safety. With some knowledge you’ll find it is not the mystery you may have thought it to be. For more information on pruning, please see these IFAS documents, or contact local extension agent for additional information on this and any topic regarding your gardens and more.

Pruning Hydrangeas

Pruning Hydrangeas

We grow many types of hydrangeas in North Florida. In order to prune your hydrangeas at the correct time of year, you need to identify which types you have in your garden.

Bigleaf hydrangea (Hydrangea macrophylla)
Bigleaf hydrangea (Hydrangea macrophylla) comes in mophead and lacecap flower forms. They bloom on old wood, so prune in summer after blooming is finished. Repeat bloomers, such as ‘Endless Summer’ bloom on both old wood from the previous year and on the current season’s wood. You can prune after the first bloom and still get a bloom later in the season.

Hydrangea macrophylla. Photo by Beth Bolles,
UF IFAS Extension Escambia County

Oakleaf hydrangea (Hydrangea quercifolia)
A native hydrangea that blooms on old wood, so prune after flowering. This type requires little pruning, only
to maintain size and shape.

Oakleaf hydrangea. Photo by Beth Bolles,
UF IFAS Extension Escambia County

Panicle hydrangea (Hydrangea paniculata)
These shrubs bloom on new wood, so prune in winter or early spring before new growth emerges. ‘Limelight’ and ‘Pee Gee’, are examples of this type. Plants only require pruning to shape or thin out the shrub.

Limelight hydrangea. Photo by Beth Bolles,
UF IFAS Extension Escambia County

Here are some additional pruning tips for your hydrangeas.

For all types, check for winter-damaged wood in early spring. Remove all dead branches before buds start to open.
Some plants need rejuvenation pruning. Old wood may die back or be less productive, so in early spring remove very old stems at the base. This stimulates new growth.
Deadheading flowers (cutting off spent blooms at a set of leaves) can happen as needed.

Select and Plant Trees for Florida’s High Wind Climate

Select and Plant Trees for Florida’s High Wind Climate

Many future problems can be avoided by paying attention to tree selection, planting and maintenance in Florida’s high wind climate. We may think of tropical storms causing tree damage but our typical summer thunderstorms can produce winds in excess of 50 miles per hour with downbursts reaching over 100 mph. 

There is no way to protect trees from all storm damage. Trees are not adapted to worst-case storms, such as Hurricanes Michael or Ian, only to our average wind climate.

It’s wise to take time to select and correctly plant the right trees for North Florida.

Past hurricanes have taught us that large growing trees planted too close to curbs, sidewalks or buildings blow over easily because they don’t have adequate room to develop a sound root system. It’s best to either plant these trees farther away, plant trees that may stay small, or increase the size of space allocated for tree root growth.

Research and storms have taught us that tree roots need large soil spaces for strong, stable growth. The more rooting space trees have, the less likely they are to fail. Strong root growth is essential for tree stability and health. Large maturing trees need at least 30 feet by 30 feet (900 ft. sq.) of rooting space. Many construction practices such as paving over roots, raising and lowering soil grade, and soil compaction from equipment result in root injury for existing trees, making them less durable and less stable.

Magnolia Tree in the Landscape. Photo courtesy Stephen Greer

Studies have also shown that trees growing in groups better survive high winds compared to individual trees. A group was defined as five or more trees growing within ten feet of another tree, but not in a row.

A short list of large maturing, storm resistant trees to consider include live oak, sand live oak, bald cypress, pond cypress, black gum and magnolia.

Do some homework and take a look at tree species that have done well in your area. If you don’t want or need a large tree in your yard, there are many small and medium sized wind-resistant trees from which to choose, like Crape Myrtle and Vitex. Many palms are wind resistant too, particularly the cabbage palm.

Having success with trees in the landscape involves starting with healthy, well-developed trees. Plant the right tree in the right place. Follow good planting procedures, including not planting trees too deep and providing adequate root space to allow for strong, healthy root growth. Practice correct maintenance techniques, which includes learning how to prune to produce a structurally sound tree. Finally, consider if it is time to be proactive and have large over-mature, declining trees removed and replaced before the next storm.

The following UF/IFAS Extension link, Trees and Hurricanes, includes the most current recommendations on tree selection, planting and pruning. https://hort.ifas.ufl.edu/treesandhurricanes/wind_and_trees.shtml

February Gardening Dos and Don’ts

February Gardening Dos and Don’ts

February can be a confusing month for North Florida gardeners. Winter isn’t over. So, don’t let spring fever cause you to make some gardening mistakes. Let’s take a look at some dos and don’ts of February gardening.

 

Despite colder temperatures that we can experience this month, it’s still okay to plant trees and shrubs from containers. The roots are better protected in the ground and will quickly grow outward to establish as compared to being exposed to cold temperatures above ground, confined in a container. But be cautious about planting cold sensitive tropical plants too soon while freezing weather is likely. Bare-root trees and shrubs should be in the ground promptly. This includes bare-root nut and fruit trees, pine and hardwood tree seedlings and bare-root roses. Dormant season planting allows time for establishment before hot weather arrives.

 

February is a good time to transplant or move trees and shrubs that are in the wrong place. Consider moving plants that require pruning to force them to “fit” into small or confined spaces. Move them to an appropriate location where they can grow to full size. Then you can plant something new and appropriately sized for replacement. Of course, they need to be reasonable in size to move.

 

Bush rose plant correctly pruned

Bush rose plant correctly pruned. Photo credit: Matt Orwat

Late February is a good time to prune overgrown shrubs such as ligustrum and holly. These plants usually respond well to severe pruning, if necessary. But remember, they will eventually regrow to their larger size. Prune to shape and thin broadleaf evergreens and deciduous flowering trees such as oleander, crape myrtle and vitex. Avoid severely pruning narrow leaf evergreens such as junipers because they have few buds on old wood from which to form new growth. Mid-February is a good time to prune bush roses, removing dead or weak canes. Leave several healthy canes and cut these back to about eighteen inches. Delay doing much pruning on early spring flowering shrubs such as azalea until shortly after they flower. Pruning these plants now will remove present flower buds before they can open. Prune deciduous fruit trees such as peach, plum and apple. Now is also the time to prune ornamental grasses such as muhly grass.

 

If your lawn has a history of problems with summer annual weeds such as crabgrass, apply a preemergence herbicide. This should be done February 15 to March 1 when day temperatures reach 65° to 70°F for 4 or 5 consecutive days. A second application may be needed eight weeks later. Many people fertilize their lawns too early. Wait until mid-April to fertilize to prevent lawn injury and for the most efficient use of the fertilizer.

Winter Planting and Spring Preparing

Winter Planting and Spring Preparing

Violas. Photo Credit: University of Florida/IFAS Extension

It is freezing cold this week and hard to believe that we are already talking about “What to Plant” and “What to Do” to get started early. In North Florida there are cool-season annuals that can be planted now. The list includes pansies, violas, petunias, and snapdragons. As we are coming to the end of January it is time to plant crinum, agapanthus and gloriosa lily bulbs.  Make sure to mulch these areas after planting to protect them from the cold temperatures. This is also the month to plant camellias, which these come in many colors and forms that your local nurseries will carry this time of year. If you haven’t planted all your cool season crops there is still time to do that now such as broccoli, kale, carrots, and lettuce. Irish potatoes can be planted now as well.

Now you might be asking “What can I do?”. January is a great time to prune non-spring flowering shrubs and trees to improve their form. This is a good time to plant deciduous fruit trees, this will give their roots time to develop before the warmer spring temperatures. Since existing trees are dormant, it is a good time to prune and fertilize them. When the temperatures are near freezing many of the tender plants will need to be covered to minimize damage.  It’s a good time to plant a tree.  Hurricane-resistant trees include live oaks, bald cypress, cabbage palms, and southern magnolias.  It’s time to remove those dead spent seed pods on your crape myrtles and removing any crossing branches and twiggy growth will improve the appearance and the form of the plant.

Potatoes planted in mid-February were ready to harvest in mid-May in Bay County. Photo: Vicki Evans, UF/IFAS Master Gardener of the plant.

As we go into February it will soon be time to apply a preemergence weed killer to your lawns to prevent warm-season weeds. Temperatures must rise to 65°F for 4 to 5 consecutive days before you do a preemergence application and make sure you are not using a weed and feed fertilizer.  Citrus and other fruit trees can be fertilized at this time. The amount and frequency will depend on the age and type of fruit tree you are growing.  Avoid pruning Citrus until spring to avoid any injury since cold temperatures are still possible.  It is time to prune those roses this month to remove damaged canes and improve the overall form.  After the pruning is complete you can fertilize and apply a fresh layer of mulch.  They should begin blooming within 8 to 9 weeks after being pruned.

Dianthus, pansies, violas, and dusty millers are annuals that can take a chill and should be planted in February.  You can continue to plant crinum and agapanthus this month and add on amaryllis and rain lily bulbs as well.  If it has been dry make sure to provide plenty of water for the bulbs to establish and continue to protect them from the cold by adding mulch. Trees and shrubs will begin to bloom this month including red maples and star magnolias. Continue planting potatoes throughout the month and towards the end of February warm-season crops like tomatoes and pepper can be planted but be prepared to protect them from any late frosts.

Thinking about Planting a Tree?

Thinking about Planting a Tree?

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.