As you know, April is one of the most stressful months on the calendar, and it has nothing to do with the dreaded income tax deadline. Homeowners in southern Florida also need to worry about the cumulative effects of the long dry season. In a normal winter, April is not only mostly sunny, but also windy and increasingly warm. That combination puts a premium on diligence in caring for plants in containers and in the ground. A few days of inattention can have detrimental––and even lethal––effects on plants in the landscape.
Unfortunately, the early months of 2018 have been even drier than normal for most of our region. Through April 12, rainfall at the international airports in Miami-Dade and Broward counties is 5½ and 6½ in., respectively, below average for the year.
Since many plants have already resumed active growth, now is the time to start preparing for the summer months. With the rainy season still about five weeks away, it is especially important to keep plants well-irrigated. Even the occasional rain shower may not be enough to hydrate thirsty shrubs and trees. Be sure to water inground plants thoroughly so that moisture reaches deeper parts of the root system.
The next concern is fertilization. With the risk of frost long-past, now is the time to make the first application of the year. Be sure to use the product in accordance with label instructions. Do not succumb to the notion that if a little fertilizer is good, a lot is even better. The salts inherent in the chemical compounds of commercial fertilizers can kill, or at least burn, shrubs or trees if applied in excess.
The choice of fertilizer formulations is also important. Since the soils of southern Florida are mostly bereft of important nutrients, it is beneficial to use a fertilizer that contains a variety of elements. A good palm special fertilizer will fill that need for a wide array of plant species. To see what you’re getting, be sure to read the guaranteed analysis that, by law, must appear on every bag of fertilizer. Beneath the major elements––nitrogen (N), phosphorous (P), and potassium (K)––is a list of other elements present in trace amounts.
Richard Lyons’ Nursery recommends that homeowners apply fertilizer 2-3 times a year. If you choose two treatments, do the first now and the second in September. If you prefer to make three applications, do the first now, the second in June or July, and the third in September or October.
There are several important caveats to observe in fertilizing your plants: (1) Avoid application during cold weather. Generally, when soil is cold, the ability of roots to take up nutrients is greatly diminished. However, a nutritional spray can be used at any time of year, since it is applied to the undersides of leaves and therefore bypasses roots. (2) Distribute fertilizer evenly over the root system of the plant. For trees, the key area is that lying within the edges of the canopy. Leaving little piles of fertilizer can burn roots. (3) Make sure that soil is moist before applying fertilizer, and then water the product in afterward. (4) Do not use fertilizers intended for inground plants on containerized plants; their formulations tend to be too strong.