Growing Tomatoes in Zones 9 and 10

My first vegetable garden in South Florida was a crop failure. I thought I had a green thumb because I was able to grow many productive gardens from scratch in Michigan and Illinois. But there was the root of my mistake- I planted as I had done up north, in the spring.

30 years ago I learned that timing is one dramatic difference that must be obeyed. Plan in September, plant in October, harvest from Thanksgiving ’till Christmas. And if time and space and weather allows, plant again in January to hurry up and harvest before the heat of April and the rotting rains of May.

I have started dozens of gardens in Cape Coral, Lehigh Acres, Naples, and Fort Myers. Here are the few things I do to assure a bumper crop of delicious tomatoes every year.

  1. Start plants from seed. Because I love the full, complex flavor of heirlooms, they are all tomato seedlings (1)available from seed but rarely do you find starter plants in garden centers. I use Fafard growing mix in 4″ pots. (Typical germination mix is too fine and holds too much water.) There are small bags of “complete” available only at independent garden centers and large bags (3 cubic feet) of #3. These media (no soil, only lightweight, clean ingredients of peat, vermiculite, perlite, and pine bark) give the ideal ratio of water retention and drainage. I plant two seeds per pot and grow them in full, direct sunlight. This makes for a shorter seedling with thick stems.
  2. Poor soil is our curse. In South Florida we have great growing conditions: Warm Garden 2temperatures, sunny days, and some rainfall but typical, urban soil is fill dirt composed of sand/rocks/shell. The pH is very high (nearly 8) and often it is teaming with nematodes: microscopic eel worms that attack tomato roots. Improve your soil with liberal applications of organic matter. I have used bulk compost from a local vegetation recycling yard and bulk potting soil by the yard. Canadian peat moss is another excellent additive to help hold water and help make the soil slightly acid.
  3. Nematodes are microscopic eel worms that inhabit the soil and cause serious damage to roots of vegetables. There is no nematicide that “nukes” the soil for us home owners. (There used to be one called Vapam and it was extremely toxic.) There were organic options like Root Guard and Clandosan composed of crustacean shells that is incorporated in the soil pre-planting but had very limited affect. Solarizing with clear plastic can help. Growing the nematocidal marigold as a cover crop during summer can help too. The best pre-plant treatment I’ve used is combining Zerotol and Azaguard as a drench. Repeat twice.
  4. Incorporate fertilizer before planting.  Let’s not argue about organic versus chemical fertilizers. It is your personal preference. I have used both with equal results but because we have poor soils and a heavy-feeding crop I incorporate a complete organic fertilizer at planting, then supplement with liquid feed monthly. I used to buy 50# bags of greensand, bone meal, and composted turkey manure and layer it on before rototilling. I have used Mighty Grow Organic 4-3-4 with great results but they have gone out of business, leaving Espoma as the best organic, granular option.
  5. Insects are a minor problem and most of them can be prevented with Neem. Just don’t spray in the heat of a 90 degree day, because you could burn the leaves. Morning is the safest time to spray. Hornworms and fruitworms are controlled with Thuricide or Conserve.
  6. Fungal disease is the major problem. High temperatures and high humidity encourage the growth of leaf-attacking fungi. Prevent by spraying with Garden Friendly Fungicide, and/or Dithane. Commercial growers choose varieties that are resistant to nematodes, fungi, bacteria, and viruses. Seed catalogs give you those options too but I have found some of them lacking in taste. I’d rather battle the elements for a succulent “Marvel Stripe” than a hard, red orb you find in the store.
  7. Stake them up. Typical tomato plants are vines that, if allowed to crawl along the ground, will decay. By forcing them up a stake you will get more clean fruit per square foot and less disease problems.
  8. Why not a pot? Excellent idea because then you have complete control over the quality of soil and quantity of water. I use Fafard #52 in large pots for its excellent drainage. A trade “seven gallon squat” pot is 14″ in diameter and is fine for a single dwarf tomato plant and a “fifteen gallon” pot is 18″ in diameter and is fine for one full sized plant. I planted two ‘Kosovo’ plants in a “25 gallon” pot (24″ in diameter) and they got 8′ high and 10′ wide. There is no need to put anything else in the bottom of the pot. If you put a layer of rocks in the bottom you could actually interfere with drainage. A well-drained growing medium is all you need.
Dwarf tomatoes and standard plants in the background.