Watchwords for August: fertilize, weed, prune

Many gardeners think August is too hot to work but a great month to sit under the shade of their trees, eat mangoes and plan their fall gardens.

While August can be a difficult month for garden work because of high temperatures and rainy weather, it can also be very rewarding.

A little labor this month to maintain your landscape will pay you dividends in flowers, fruit, wildlife and beauty in the coming seasons.

FERTILIZE NOW

August is one of the hottest months in South Florida and falls right in the middle of our rainy season. Those conditions make this an ideal time to apply fertilizer.

It is important to note, that by making good plant choices -- natives and plants adapted to our soil -- you can eliminate the need for most fertilizers. But due to our alkaline, rocky soil, some plants -- including hibiscus, ixoras, gardenias, some palms and most fruit trees -- need supplemental fertilizer.

The essential elements that are needed by plants can be divided into two categories: macro and micro elements. Both are equally necessary.

Macros are applied in a granular form two or three times a year and consist of nine elements, including nitrogen, phosphorus and potassium. A bag of granular fertilizer will have three numbers, such as 8-3-9. These numbers correspond to the percentage of nitrogen, phosphorus and potassium in the bag.

Most plants do well with a balanced fertilizer, a 6-6-6. Fruit trees, excluding mangoes, do best with 8-3-9. For mangoes, use 0-0-50. Many palms and ornamentals thrive with 8-2-12 or 12-4-12.

Macros are applied lightly and evenly along the drip line at a rate of one handful of fertilizer per inch of diameter of the tree's trunk. A tree with a three-inch diameter trunk would get three handfuls of fertilizer. The drip line is an imaginary line that circles the tree just below the furthest branches of the tree. The feeder roots that take up nutrients are found here and just beyond the drip line.

APPLY MICROS

There are seven micro elements, including iron, zinc, boron and manganese. These should be applied generously in the form of a foliar spray to the leaves of your plantings twice a year, in June and August. Iron can also be applied as a drench using the chelated form sold as Sequestrene 138. Drenches should be poured along the drip line.

Make sure you buy your fertilizer from a South Florida company where they formulate their mixes specifically for our soils.

August is also a good time to prune your mango trees. A mature tree should be pruned once a year after the fruit has been harvested to keep the tree small enough that the harvesting can be done by hand. If your tree is already very large, you may need to consult a certified arborist.

If your tree is still manageable, you can control its growth by removing any strong vertical branches and encouraging the horizontal growth, as well as by removing larger branches in an attempt to renew the canopy over time.

Never prune more than a third of your tree's canopy. It is perfectly acceptable to leave some parts of the tree to be pruned next year. If a mango tree is pruned heavily, it will skip fruit production for a year or two while it regrows the foliage that was lost.

You must also stay on top of weeds in your garden this month. Hand pulling or hoeing is preferred to chemical control. Generous applications of mulch after an area has been weeded will help keep the unwanted guests from coming back.

Vegetable beds should be prepared for planting in October by tilling the soil and working any weeds that have moved into your vegetable garden into the soil.