Proper care may help to revitalize damaged citrus trees
Citrus in the home landscape has gained popularity in Northwest Florida. Like any fruit-bearing plant, proper care is necessary to obtain high quality, delicious fruit. Tending to freeze damage and proper fertilization will be important steps in taking care of your citrus plants this spring and summer.
Citrus trees are evergreen and never become fully dormant. Therefore, freeze damage can be a problem. In general, limes and lemons are the most sensitive to cold--temperatures in the mid 20’s are likely to cause damage. Mandarins are generally the most cold-tolerant citrus selections. However, any young tree is susceptible to cold damage unless properly protected.
Detecting freeze damage
How will you know if your citrus has been damaged by the cold? Leaves on a freeze-damaged citrus tree will be hard and brittle and often curl. If the damage is severe, the leaves will fall from the tree. Freeze damage can also cause the trunk and larger branches to split and the bark to become loose. Twigs and branches may continue to die for up to two years following a severe freeze.
Prune as little as possible
How do you deal with freeze damage? The trick is to remove as little of the plant as possible. Therefore, pruning out damaged branches and limbs must be postponed until the extent of injury is obvious. Normally, the damage is evident after the second flush of growth following the freeze, usually in July or August.
If a one or two-year-old citrus tree has been killed almost to the ground, it’s important to determine whether the dead wood extends below the bud union, something best done in April or later. If only the roots survive and grow back, you may be left with an unproductive rootstock instead of the true-to-type citrus tree you originally planted. In this case, the tree should be replaced. If there is enough live wood above the bud union to grow a strong shoot, a new trunk will develop.
Use a “citrus special” fertilizer
While fertilization of many other plants in the Florida landscape is not always necessary and may contribute to runoff, for citrus trees it is necessary for success. When selecting a fertilizer, choose a “citrus special” fertilizer.
Over fertilizing may be just as harmful as not applying enough. Excess nitrogen can produce abundant leaves but may reduce fruit production. In some cases, over-fertilization can burn, causing injury or death of the tree.
Two different fertilization schedules are suggested: one is for young, non-bearing trees, where leaf and stem growth is maximized and fruit production is reduced. After your tree is established, you’ll need to replace the nutrients that it used up in fruit production to provide enough nutrients to keep it growing.
Young trees should be fertilized with light applications of fertilizer approximately every six weeks beginning in March. Avoid fertilization during the summer rainy season because of potential leaching. Do not fertilize between October and February to prevent winter growth flushes. Apply fertilizer in a three-foot diameter circle around the tree.
Mature trees may be fertilized about three times per year: spring, early summer, and again in late summer. But your tree may produce more fruit when fertilized only once or twice per year. Base this on experience, soil type and tree response.
Theresa Friday is the Residential Horticulture Extension Agent for Santa Rosa County. The use of trade names, if used in this article, is solely for the purpose of providing specific information. It is not a guarantee, warranty, or endorsement of the product name(s) and does not signify that they are approved to the exclusion of others.
