Fall tomatoes are in the nursery! Look in the greenhouse and the tables are lined with fall tomatoes, many different varieties. Can you picture it? In your excitement to see tomato plants again, you purchase a 6 pack of tomatoes and happily walk out the nursery gates only to be smacked in the face by a blast of heat from the summer sun. Suddenly you look at your tomatoes and your smile fades. How will these little 2” tomatoes have a chance against the withering heat? You think about returning your tomatoes and walking away in defeat, but you stop because you have heard (multiple times from Rainbow Gardens) that you need to plant your fall tomatoes early in San Antonio.

Don’t question yourself, you are correct. You do need to buy your tomato plants early and you do need to plant them early; but what you also need is a quick lesson on what to do with your tomatoes in between buying them and planting them. This quick lesson will have your little tomato transplants growing into strong, hardy transplants ready to be planted in your gardens in no time at all. 

Purchase fall tomatoes in late July and early August when the selection is the best. We simply don’t bring in tomatoes after August because we know it is too late for you to complete the steps needed to grow your tomatoes properly by then.

Fall tomatoes getting repotted to larger pots.

Bump your tomatoes up to a larger pot. Tomatoes in 4” pots should be repotted into gallon sized containers and tomatoes in 6-packs that are in 2” cells should be bumped up to 4” pots and then eventually gallon pots. (You can go directly to gallon sized from 2″ if you’d like to skip a step, we just think the roots grow nice and full when bumping up to the next sized pot first.) The smaller transplants straight from the nursery wont be able to directly take the summer heat in the garden. Bumping your tomatoes up to larger containers as opposed to sticking them straight into the garden creates larger, stronger transplants that are setting blooms or close to setting blooms when it is time to go into the garden. This process takes about 4 weeks, so you can see why purchasing tomatoes and repotting them at the right time is important.

Protect your newly bumped up tomatoes from the harsh August sun. While your tomato transplants grow in their larger pots, you can set them outside in a shady area or an area that gets filtered light all day. By carefully monitoring them and gradually exposing them to more sunlight each week, you are strengthening your plants, or hardening them off, so that they will be better equipped to handle the full sun once they are in your garden bed. You can also protect your tomatoes by making a little shelter out of a bent piece of cardboard.

Fall tomatoes with yellow blooms for fruiting.

Plant your gallon-sized, strong transplants into the garden no later than Sept 1st – 15th. Around these dates, night temperatures are usually consistently under 73°. It is at this night temperature that fruit will be able to set on the tomato blooms. If the night temperature stays higher than 73°, you will have trouble getting fruit to set, especially for those larger tomato varieties like Beefsteak. Medium-sized tomatoes like Valley Girl and other smaller to medium types are recommended for our area, as well as cherry tomato varieties. (Cherry tomatoes will still fruit at higher night temperatures.)

The reason our recommendations for tomato varieties and planting dates are so important for tomato production is due to the days to maturity for each individual tomato variety.

  • If you pick a large tomato variety that takes over 80 days to produce fruit to maturity, there is little chance you will get a harvest before the first freeze blows in and kills off your tomato plant.
  • If you choose the right tomato variety (a type with 65-70 days or under to maturity) but plant it too late, you risk the same problem. So choosing the right type of tomato and planting it at the right time of the year is crucial to success when growing fall tomatoes.

For more on choosing the right tomatoes, more success in growing fall tomatoes, and extra tomato tips, see the links.

Good luck!

The Happy Gardener, Lisa Mulroy