Not that you can feel it, but we’ve actually been on the downside of summer heat for several weeks. According to statistics published in the Miami Herald, as of mid-September the average daily temperature should be 83°, a drop of two degrees from the summertime high in parts of July and August. With a little bit of imagination, it’s possible to sense the pleasant changes that come with the end of the rainy season.
Those changes—however subtle they might be—dictate different behavior toward our plants. Richard Lyons’ Nursery is happy to offer a few observations for dealing with the approaching onset of autumn weather.
1) Do not root prune any trees that require a lengthy root-pruning process. The palm Copernicia macroglossa is one example, but that advice holds true for large specimens of other trees, many of which may require gradual root-pruning over a 12-month period. If they’re not transplanted during the hottest, wettest time of the year, they tend to have great difficulty recovering.
2) This is the time to start planting winter vegetables and herbs. The plants that grow well in the summer around the rest of the country are generally successful in the winter in southern Florida. The list includes onions, sugar peas, dikon, dill, basil, carrots, beans, collards, cauliflower, broccoli and cabbage. You can also continue to plant vegetables that survive year-round in our region; they include parsley, rosemary, mint, thyme, chives and Cuban oregano. In addition, there has been some success in having Thai basil survive our summers.
3) Start making adjustments in your watering regimen when the humidity begins to drop. Lower relative humidity means noticeably lower minimum temperatures by mid-October. You can consider the rainy season over when dewpoints regularly drop below 70°. At that point, some plants, particularly those in containers, start to experience problems with hydration. You should monitor your plants closely to see if you need to increase irrigation through the fall months.