Live Oak — By Carolyn Saft
Suwannee County UF/IFAS Extension Horticulture Agent II
Our weather has created a dilemma for plant enthusiasts. First the temperatures were cool, and then warm and then freezing. Ideally our plants prefer for temps to be warm, and then get cooler, and then get cold before it drops to freezing. This scenario allows plants to acclimate to the winter season and go into dormancy. In my yard, some of my azaleas started to flower at the end of January and beginning of February, then we had freezing temperatures and the flowers froze on the plant. I have other plants that have a few slow forming buds that are hanging on for dear life. It is tempting during the warming trends to get out and start pruning off all those ugly frozen flowers, but it is best to hold off on pruning until after the last winter freeze. With woody plants such as Hydrangea and Azaleas, that may have received winter injury, wait until late March or April to do any cutting back. We don’t want to be too quick to bring them out of their dormant state. If the plants start to flush on their own, then that’s another matter, so cutting out the woody portions above where they flush then will have little impact on dormancy.
When it is time to prune, make sure you are using bypass pruners and not anvil pruners on the living branches of your plants. Anvil pruners tend to crush the stems of plants and make it difficult for plants to heal quickly. Additionally, use pruners with a sharp clean blade. First, it makes it easier to cut which causes less stress to you and the plant. Second, pruning blades sprayed with 100 percent isopropyl alcohol or a 10 percent bleach and water solution will be less likely to spread disease or insects from plant to plant. For more info, go to Pruning Landscape Plants at http://edis.ifas.ufl.edu/pdffiles/MG/MG08700.pdf Cooler weather is a good time to mulch plant beds with mulches that will add organic matter for plant nutrition and conserve moisture in the root zone.
Mulching also will help keep weeds down and grass away from the base of trees and shrubs. This practice reduces the chance of injury from a string trimmer and also reduces competition between desirable plants and weeds for nutrients and water. When distributing mulch, keep it at least two inches away from the base of the plant. Avoid mounding it against tree trunks as this can rot the tree’s bark or provide a hiding place for rodents to live and gnaw on the tree bark. The practice of piling mulch up the trunk of the tree is called volcano mulching and can result in tree death over time. To be effective against weeds, the mulch must be 2”-3” thick so it blocks out sunlight which is needed for many weeds to germinate. Choosing an organic mulch will serve as a substitute for fertilizer over a period of time. As the mulch breaks down, it provides the needed nutrients plants need. Using materials such as leaves, pine needles, pine bark nuggets and partially rotted compost will go a long way toward providing a tree or shrub adequate nutrition for growth once it is established. The mulched areas should not be small rings or “donuts” placed around the tree trunk. To really make an impact, their size should increase as the size for the tree or shrub increases. The University of Florida suggests that for every inch of trunk diameter the mulched area should be two feet in diameter. For example: a four inch diameter tree should have a mulched circle under it eight feet in diameter - four feet out in all directions. For more info, go to: Mulches in the Landscape @ http://edis.ifas.ufl.edu/pdffiles/MG/MG25100.pdf
Whether or not we should be fertilizing woody trees and shrubs, once they are established, has been studied a lot by the University of Florida. Keep in mind, you need a purpose
for fertilizing, just like you should have a reason to prune. So, if you are a gardener who severely prunes all your shrubs into tight lollipops or squares, then plan on fertilizing your plants at least once a year. Such unfriendly pruning practices severely stresses/weakens most woody plants and requires they be fertilized to keep them healthy and bounce back after such a massive removal of their leaves and stems. If you don’t, then you’re likely to see your plants slowly declining especially if you are not mulching with organic mulches. On the other hand, if you only lightly prune and the plant is growing well, why push it with additional fertilizers which may cause it to need more pruning to keep it at a desirable size. Over fertilization also causes many more tender growth flushes, making the plant need more water and also causing it to become more attractive to female insects looking for tender leaves to lay their eggs, and more prone to leaf pathogens?
For more information on the irrigation and fertilizer needs of woody shrubs and trees in Florida go to: http://edis.ifas.ufl.edu/ep110
Mulching and studying up on your plants should keep you busy until we are sure we won’t have another freeze. Resist the temptation to get out and prune for a few more weeks.
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