Four hurricanes blew over or past the Florida Keys in the hurricane season just ended, stripping our plants of foliage, twisting branches, breaking fronds, uprooting trees, spraying saltwater on the foliage and inundating the plants’ root zones.</p><p>Here are some lessons learned on how to help your landscape weather future hurricanes.</p><p><b> Wind lessons</b> </p><p><li> How wind-tolerant are your landscape plants? During Hurricane Andrew in 1992, the most wind-resistant native trees were the Spanish stopper, gumbo limbo, lignumvitae, paradise tree, redberry stopper and white stopper.</p><p><li> Trees that are preventively pruned are less likely to fall than neglected trees. Reducing the length of overextended limbs and reducing the length of branches and stems with bark inclusions lessens the probability of branches breaking from the tree.</p><p><li> Apparently healthy trees can blow down because supportive roots have decayed or soil becomes soft from saturation. Trees blow over in strong winds primarily because roots are rotted, soil becomes soft from rain, or a combination of both.</p><p>Naturally occurring fungi including armillaria and others can decay roots, creating unstable trees. Root rot can be diagnosed with careful, regular inspections by accomplished arborists. Poor drainage or excessive rainfall rates can make soil soft and unable to hold trees erect.</p><p><li> Trees with one dominant trunk fare better than trees with codominant stems. Trees with one major trunk with widely spaced branches throughout the canopy have a stronger structure that has proven to be better adapted to storms than the codominant stem form.</p><p>Hire arborists with the ability to create and maintain a strong structure in your shade trees by appropriate pruning techniques. This is the best known way to help your tree make it through the storm with little damage.</p><p><li> Root defects such as girdling roots cause trees to blow over. Roots that circle next to or near the trunk were associated with numerous fallen trees. In one case, one huge root circled the trunk, causing a trunk constriction. This inhibited the root system and root flare from developing properly on one side of the tree and appeared to cause decay in the center of the trunk. Trees with circling roots often blow over in the direction away from the circling root. </p><p><li> Trees grown in confined soil spaces are prone to blowing over. Trees with root systems confined to relatively small soil spaces are not as stable as trees allowed to develop more spreading roots systems.</p><p><li> Queen palms are prone to falling over; cabbage, royal and Phoenix palms are much more resistant to blow over.</p><p><li> The most wind resistant form for a tree is one with a central leader and a well-spaced framework of branches that go around and up and down the trunk. There should be no narrow forks or branches leaving the trunk at an acute angle, since these branches are likely to split under stress. Limb crotches that form a U shape (45- to 90-degree angle) are less likely to split than narrow V-crotches of less than 40 degrees.</p><p><li> A wind-resistant tree is the result of regular care since its early life. Young trees should not be cut back to make them bushy, but rather be encouraged to form a strong leader with well-spaced laterals. Later pruning should consist of forming a well-spaced framework of strong branches and a pleasing outline to the tree. Remove dead or diseased branches anytime.</p><p><li> Tree or shrub “hatracking” or “topping” may cause the tree to put on a thick flush of growth that acts as a sail or kite in high winds. Trimming trees into a lollipop shape increases the likelihood of causing them to topple over during winds. Further, severe hatracking can damage the underground root system and weaken the tree, especially in wet, soggy soil.</p><p><b> Salt lessons</b> </p><p>How salt-tolerant are your plants? Their ability to tolerate salt is based on saltwater spray on the foliage or by storm surge that floods the root zone.</p><p>Salt tolerance of landscape plants is divided into three categories: Low, medium and high. Low indicates that the plant is largely intolerant of salt on the roots or the leaves; moderate refers to plants that require protection from direct spray and intensely saline water but can tolerate mildly brackish water and some incidental spray; high indicates a plant that can be grown in exposed seaside locations.</p><p><li> Storm surge carries large amounts of sand, silt, organic material (such as seaweed and small sea creatures), and anything else it could float and pick up. Once the storm subsides, the water will begin to settle and flow off the islands, leaving us with deposits of almost everything imaginable. Most of the storm tides are gone within a few hours, except for isolated low pockets.</p><p>Once the water recedes, immediate care should be given valuable plants. If possible, foliage and branches of plants should be washed with a strong stream of water to remove all salt, mud and other debris.</p><p>All over the ground there will be a thin to heavy layer of silty material. When this dries, it will actually seal in the salt around the plant roots but, more devastatingly, will cut off the air supply to those roots. This material should be raked away as quickly as possible from under the roots of shrubs and small trees. Large trees will tolerate this silt better than smaller trees so do the most thorough job of attempted removal around your shrubs and fruit trees.</p><p><li> Some plants such as introduced exotic species may have a problem with salt deposits but most plants will survive them. The silt probably offers more of a hazard to plants than do the salts.</p><p>It is difficult to determine exactly which plants you are likely to lose after the storm. Severity of damage will depend upon the type of plant, age of the plant, amount of salt and silt that remains, period of submergence, etc.</p><p>Certainly after a severe storm, you will come to appreciate the hardiness of some of our native plants, which have stood through many storms, and see the value of preserving them in the landscape whenever possible instead of going totally to introduced species.