September 2021 in the South Florida Garden

February 26, 2024

September Down Here Is Summer-Not Fall!

It's September in our South Florida garden.

It’s September In our South Florida garden. In our coastal town on the edge of the western Everglades, it’s still summer! Our average temperature is 85, and our low is 75. We are at the peak of hurricane season and we keep the storm shutters ready to go!

Visiting South Florida In Fall

Taking a vacation to Florida this month? Bring your swimsuit. This is a beach vacation with plenty of fishing, gardens to visit, theme parks, and alfresco meals. Here is a monthly story about visiting Florida.

It’s Not September As You Know It!

In most of the temperate world, September sees change. It cools off, the sun is at your back, In cooler climes, we felt that anticipation of coolness, crisp mornings, trees in bright colors, the holidays to come, and just a touch of melancholy as we see the end of a perfectly good year around the corner.

In September down here, we anticipate the inevitable chores. We are preparing for change to come, but we do not put the garden to sleep as you may be doing.

latitude and longitude on globe

Not for us! Not down here! Even the wonderful quotations we all know about fall are all wrong here in latitude 26.177624 and longitude 81.806946.

“All at once summer collapsed into fall!.”

-Oscar Wild

Even Oscar Wild Was Wrong!

September in Our South Florida Garden is Subtropical Springtime

Spring in a sub-tropical climate is a split offering. We get the end of dormancy and the start of growth early in the year, like everyone else, but then the wet heat comes. In summer, we grow lush tropical blossoms along with sweet potatoes and fruit with hard to decipher names. We love summer salad but can’t produce our own lettuce! in our hottest weather, we all eat greens from places like Wisconsin!

What’s In Bloom?


The image at the beginning of this piece is an ornamental grass called Muhlenbergia capillaries, it is just starting to bloom in this lovely shade of magenta for the fall. Otherwise, it is pleasant, waving, green grass. It is not demanding of soil but prefers good drainage. We use it on the highest side of the pond edge where it adds a natural element to the waterside. The wading birds are happy to wander through it.


Mussaenda in our South Florida Garden. This one is 10' tall!

In summer our residents console themselves with equatorial blossoms so richly complex that they contain other blossoms and exotic scents!

But no beefsteak tomatoes! They won’t survive the heat.

This is Mussaenda, it grows 10′ tall and is evergreen all year long, and is in flower essentially all year!

It grows in zone 9 and warmer and in the north, you can make a spectacular annual of it.

Fall, Our Extra Vernal Season

In fall, our bonus is a second spring-for us the real one! We plant our most diverse set of vegetables in the fall and we do it even as we prepare the turf for dormancy!

We have long since pruned our flowering shrubs. That’s because our flowering shrubs now bloom in early winter when in our northern climate gardens, they used to be dormant. Our seasons are mild and comfortable; our environment, lush. But we do think twice about how to define spring.

So, as a transplanted northerner, I have learned to parse my ambitions. Not quite the old days; so blossoms in April and green beans in October. I plant some summer annuals in September and October and duplicate some of my New England mother’s color garden, once planted in May!

More of what’s In Bloom Now?

Look For Canna flaccida, richly compound Gingers and Phillipine Violet In Our Borders

Native yellow, Canna Flaccida, lily-like, and the color of butter rise at the pond edge. The wading birds hunt within its arrow-shaped foliage.

The garden is in transition. Some lush, tropicals bloom in summer and we still see dense flowers from Mussaenda, a plant with rich clumping, hydrangea-like blossoms. its 100 or so species come from Asia and Africa. The Philippine Violet, a broadleaf perennial with beautiful lavender blossoms, is a cool-season bloomer and is now just beginning to flower. We sit above the pond and watch the hummingbirds that can’t stay away from it.

Some of the luxuriant gingers are in bloom today, some have finished earlier in the summer.

Mona Lavender

Mona lavender in bloom in our South Florida garden.

This fairly new hybrid is from the Kirstenbosch Botanical Garden in South Africa. It, like the Phillippine Violet, is a cool-season bloomer, green all summer. Cold-hardy in zones 9b-10 you can also grow Mona Lavender indoors as a colorful house plant. It’s a charmer, bright green leaves, with purple undersides, and long spikes of lavender flowers, that are remarkably like tubular orchids. Here is more information on Mona Lavender.

An Idea To Try This Fall-Purple

If you love to decorate for fall; Halloween, and Thanksgiving but are moving away from orange everywhere, try purple! It gives you a sense of autumn but it feels new. It also allows you to blend in the pink shades if that is your inclination but is accented brilliantly by orange too!

purple persian shield

As I look around town, our most inventive gardeners are adding purple shades to the garden. Mona Lavender, Persian Shield (to the left), purple Salvia, and for the pollinators, purple Pentas.

It gives an air of fresh brightness to our green spaces. Try it in your garden.

A Tropical To Grow Indoors

croton plant

For a tropical version of fall shades with vivid golds, plant some Croton. Northern garden centers are showing it as a fall decoration for pots on the front porch. You can bring it indoors as a colorful house plant in the winter.

In The Herb Garden

We are adding to the garden for fall and winter meals. A Florida advantage is the fact that we grow herbs outdoors all year round. See the chart, below for seasonal notes on Florida herbs. For more information on growing and cooking with herbs, no matter where you are. try this article Culinary Herbs-Garden to Kitchen. It will describe herb gardens and link you to detailed information on specific herbs.

Your Temperate Climate Herb Garden

For information on the end-of-season herb garden and ideas for bringing fresh herb plants indoors to grow for winter use, you might like this article. What to do with the herb garden in fall.

The Raised Bed Edible Garden

I started this project next to the pool last spring. It is a small elevated bed, and pretty enough to decorate the patio. You really can lie on the lounge chairs and pick a strawberry without getting up!

We ate wonderful lettuce and spinach from this bed and the strawberries are overtaking their allotted space. I’ll need to find some of them, new homes.

I think this year I will emphasize the delicious fresh greens, herbs, and strawberries. It will become a salad and cocktail garden. I’ll tell you how it goes!

What To Plant In September in Your South Florida Garden

September can be rainy for us. We watch week by week, just as we did in New England watching the frost. Down here we are watching the rain, trowel in hand. That springtime vigilance never changes, no matter where the garden (or if the calendar says it’s spring!

AnnualsIt is time to begin to add the “winter annuals.” These are often the same plants we northern transplants called the “summer annuals” in our northern gardens. Look for impatiens, alyssum, and, dianthus. (The links will take you to more details on these plants).

BulbsAgapanthus and Rain Lily, planted now will bloom next year. Bulbs for Florida UF
HerbsThis month we will replace both annual herbs and any perennials which did not survive our sloppy summers. In our garden, dill, fennel, and cilantro seem to have the most trouble in our climate.
VegetablesBroccoli, beans, carrots, lettuce, peppers, radishes, also, spinach and tomato.

South Florida Vegetable Gardening

September is an anxious month for us. We want to get started but we know it’s too early. So we busy ourselves with projects. Not planting but getting ready. South Florida has a reasonable number of vegetable cooperatives and some of them have some good ideas to offer. Here are some that look interesting.

Some garden advice from a professional co-op.

This is seasonal advice from a gardening group in Miami.

Sunpatiens are the variety that works best for us.
Impatiens-Summer Or Winter-Depends On Your Location

What To Do In October

LawnsControl winter weeds early, before they appear.
PalmsFertilize them with controlled-release forms of nitrogen, potassium, and magnesium.
Trees and Shrubs October is the last month before dormancy to fertilize trees and shrubs.
Special Situations
OleanderThe oleander caterpillar is a regular problem, eliminate them by trimming off affected branches or use BT (Bacillus thuringiensis) as a spray.
StrawberriesThis is the month to plant strawberries, They are attractive and flavorful and can be grown in beds or in containers.

NB: I make these charts using mostly recommendations from our University of Florida research. It is our land grant agricultural university, and we Master Gardeners are trained to use it. I also add recommendations from Florida-based gardeners and garden writers I admire.

What To Expect From Your Winter Trips To Florida

Palm grove

This is true of all visitors to Florida. You leave your home airport on a cold, snowy day. As you land at your Florida destination, wherever it is, the Palm trees appear through the plane’s window, and everyone cheers!

If you own some palms, see the chart above and the referenced article for fertilizer information.


What’s fall, like around here? In the north, we anticipated autumn for the coolness, the increased moisture, and the beautiful golden light, But we mentally steeled ourselves for the cold to come.

In South Florida we certainly revel in the cool mornings (while finishing up our garden sessions in the pool) we are getting less moisture, which makes us happy right now. In a few months, we will be happy to see a little rain again. The cycle goes on. And as we say down here…”and the bugs never quit.”

The light is a little softer, not the rich golden aura of a northern latitude but a subtle note. Our homes here are in a coastal community, but near to an important agricultural belt. The good, local tomatoes will be here soon! Fall is not so much a season for us; maybe a whisper.