Miami gardening, explained

1. No winter, no dormancy

Miami-Dade sits in USDA hardiness zone 10b, with coastal pockets reaching 11a. Frost is effectively absent. The last widespread damaging freeze in this part of Florida is a long way back, and most gardens here never see one.

The consequence is that plants do not go dormant. Growth slows in the cooler, drier months but never stops, which means feeding, watering and pest pressure all continue year-round. There is no winter reset — pest populations that would be knocked back by frost elsewhere simply carry over.

It also means the planting calendar is inverted relative to most gardening advice. The best planting window here is late winter through early spring — February to April — when soil is warm, storm risk is low and the plant has months to establish before summer. Planting in June, the peak of the growing season in the north, puts a new plant into heat and saturation simultaneously.

2. The soil is the real difference

This is the variable that catches people out. Miami-Dade sits on oolitic limestone, often with only a thin layer of sand or fill above it. That produces two problems at once.

Alkalinity. Soil pH typically runs 7.4 to 8.3. At that pH, iron, manganese and zinc form compounds that plant roots cannot absorb, even though the elements are physically present. The result is interveinal chlorosis — yellow leaf tissue with green veins — on new growth, which is the single most common plant complaint in this county. It is a chemistry problem, not a fertility one, and it is corrected with chelated micronutrients rather than more fertiliser.

Drainage and nutrition. Sand drains almost instantly and holds very little. Nutrients applied in a single heavy dose largely wash through. Several light applications of slow-release fertiliser across the year do far more than one large one — and Miami-Dade has ordinances restricting fertiliser application in the summer rainy season, partly to protect Biscayne Bay from exactly that runoff.

3. Two seasons, not four

The wet season runs roughly May to October: high humidity, daily afternoon storms, and rainfall that can exceed several inches in an hour. The dry season, November to April, can pass weeks with no meaningful rain at all.

This means irrigation is a seasonal instrument rather than a fixed setting. Running the same schedule year-round is the most common irrigation mistake here — it drowns plants from June to September and underwaters them from January to April. A controller that is adjusted four times a year, or a rain sensor, solves most of it.

Humidity in the wet season also drives fungal pressure. Dense canopies that never dry out develop leaf spot and root problems; spacing and airflow matter more here than in a drier climate.

The yardGrowing rows through the seasons

4. Salt, wind and storms

Coastal properties deal with salt in two forms: airborne spray, which burns foliage on exposed sides, and salt in the soil or irrigation water, which is harder to manage. Plant selection is the practical answer — clusia, cocoplum, silver buttonwood, sea grape and many palms handle it well, while most soft-leaved understorey tropicals do not.

Hurricane season runs June through November, peaking in September. It shapes two design decisions: tree species and pruning practice. Well-rooted, properly pruned trees of resilient species — live oak, gumbo limbo, sabal palmetto — perform very differently in a storm from shallow-rooted fast growers. And hard pruning in late summer, which forces soft growth exactly when winds arrive, is worth avoiding entirely.

5. What this changes in practice

• Feed little and often, with chelated micronutrients, rather than one heavy spring application.
• Water deeply and infrequently, and change the schedule seasonally rather than leaving it fixed.
• Plant February to April for the best establishment window, with a secondary window in November.
• Mulch everything — three inches, across the bed, clear of stems. It does more work here than in a temperate garden.
• Prune after flowering flushes, and avoid hard cuts from August to October.
• Choose for mature size, because growth rates here are much faster than the plant labels assume.

6. The plants that reward you

The upside of this climate is considerable. Growth rates are extraordinary — a hedge that would take five years elsewhere closes in eighteen months. Colour is available twelve months a year. And the palette includes plants that most of the country can only grow indoors.

The most reliable performers are the ones adapted to exactly these conditions: clusia, cocoplum, silver buttonwood, ixora, croton, thryallis, plumbago, firebush, bougainvillea, sabal palmetto and the Florida natives generally. Our guides to native Florida plants and tropical plants cover the palette in depth.

7. Common newcomer mistakes

1. Watering little and often. Produces shallow roots that cannot survive a hot week.
2. Treating yellow leaves as a nitrogen problem. Usually it is iron, locked up by pH.
3. Planting in June. Heat and saturation at once, with no establishment period.
4. Amending single holes heavily. Creates a bathtub in sand.
5. Running one irrigation schedule all year. Drowns in summer, starves in winter.
6. Ignoring mature size. Growth here is fast, and congestion arrives in year three rather than year ten.
7. Assuming shade plants can take Miami sun. Our light intensity is far higher than the same nominal exposure further north.

None of it is difficult once the variables are understood. Most of it is unlearning advice written for somewhere else.

Frequently asked questions

References & further reading

• USDA Plant Hardiness Zone Map
• UF/IFAS EDIS — South Florida soils and plant nutrition
• Miami-Dade County — local landscape and fertiliser ordinances
• NOAA National Hurricane Center