3 Tips for Growing Tomatoes in Gardening Containers

3 Tips for Terrific Tomatoes

There’s nothing quite like pulling a juicy tomato right off the vine. Whether you are a gardening beginner or a veteran, we’ve developed a list of tips to help you grow the best tomato plant in gardening containers. If you’ve ever attempted to grow tomatoes, you may have encountered some challenges. Tomatoes can split, get mold, or even start to rot right on the vine! Read along to see what you can do to help your tomatoes be the best they can be.

3 Tips for Growing Tomatoes in Gardening Containers

Tomato Tip #1: Choose the Right Planter for Tomatoes

If you're looking for a significant yield, ensure your planting box accommodates at least two plants. For example, the EarthBox® Container Gardening System was invented by a commercial tomato grower. It's perfect for growing two tomato plants. If you want to take up a smaller footprint, you could grow one tomato plant in the EarthBox® Root & Veg Gardening System. Reserve the EarthBox® Junior Gardening System for some basil or other herbs to complement your tomatoes.

Tomato Tip #2: Don’t Stress About the Variety of the Tomato

Most varieties will do well in containers as long as they are getting 6-8 hours of sun a day, nutrients, and plenty of water. You can easily grow determinate or indeterminate varieties in an EarthBox® Original gardening system. A determinate tomato will remain compact and bushy, and typically sets fruit in a short period of time. An indeterminate tomato will grow as a vine and set fruit as it continues to grow. Different types of tomatoes include slicing tomatoes, sauce tomatoes, or cherry tomatoes. When selecting your tomato plants, focus on how many days until your plants reach maturity, so you’ll know if you have enough growing time based on your USDA zone. Be sure to read descriptions for flavor and the best use for each variety.

Tomato Tip #3: Be Proactive

The best way to keep your tomato garden healthy is to:

  • Use a high-quality, peat-based growing medium. Avoid using topsoil, or anything that contains clay or sand. Be sure to incorporate perlite or vermiculite for aeration and drainage.
  • Mix one pound (1 lb.) of Dolomite into your growing medium during the initial set-up, and each year after when replanting. Dolomite provides calcium and magnesium, essential for growing tomatoes and also helps prevent Blossom End Rot (BER).
  • Use a high-quality granular fertilizer with plenty of Phosphorus (the “P” in N-P-K). The EarthBox® Replant Kit makes it easy to re-grow by providing a pre-measured fertilizer with an even amount of Nitrogen, Phosphorus, and Potassium; as well as pre-measured dolomite, and 2 new black/white reversible mulch covers (one for growing, one for winterizing).
  • Water regularly (or let the Automatic Watering System do it for you), since water is crucial for growing tomatoes. Be sure to keep the reservoir full, and never let it run dry. You can fill until the water begins to flow out of the overflow drain.
  • Use a trellis for your tomato plants. Indeterminate tomatoes grow on a vine and need the proper stability to grow to their maximum potential. The EarthBox® Staking System provides needed support while maintaining the portability of the planter.

Problems with Growing Tomatoes

So now you have your tomatoes planted. You’ve nurtured them, and they are getting bigger, but suddenly you have a problem with your plants. If this situation sounds familiar, here are a few examples of what may occur to your tomatoes and a few suggestions on how to resolve your issue.

Split tomatoes

Problem: My Tomatoes Keep Splitting or Cracking!

Reason: Most of the time, cracking or splitting in the tomato is due to the tomato absorbing too much moisture all at once. If there is a very dry, hot spell that is followed by a cool, heavy rain; the tomato plant may soak up all that extra moisture into the fruit and—with only so much skin to cover the outside—cracks may occur.

Solution: Don’t fear! Cracked tomatoes are fine—especially heirloom tomatoes, which are prone to cracking—and are still edible! To prevent further cracking, make sure you are providing enough water to your plants. Keep the water reservoir full. It’s common for the reservoir to run dry several times a day when tomatoes are reaching maturity, and you may have to fill it up to three times a day. For future reference, you can buy crack-resistant tomato varieties like big boy, big beef and black cherry.

Problem: My Tomato Plant’s Leaves Have Black and Yellow Spots!

Reason: Black spots on a tomato plant can probably be contributed to a type of fungus causing cankers on the plants. It’s especially common in humid and hot areas where fungus can grow rapidly.

Solution: Be sure to keep your EarthBox® gardening systems spaced far enough apart so the leaves can get air and breathe easier, and fungus will have a more difficult time establishing itself. If you’re in a high-humidity area or are expecting long periods of rain, you can pre-treat plants with a fungicide to help prevent mold and fungus.

Tomato hornwormProblem: Something is Eating My Tomato Plants!

Reason: Tomato Hornworms. You’ll want to be on the lookout for any large green caterpillars—they will eat your plants!

Solution: Try just picking them off or hosing down your plant with water. There are also organic treatments that contain the bacterium Bacillus thuringiensis (Bt) to get rid of these pests.

Note that if you find a hornworm with white rice-looking eggs on it (left), let it be. Parasitic wasps lay their eggs on them to use as a host, causing the hornworm to die.

Problem: My Tomatoes are Rotting on The Vine!

Reason: A common disorder with tomatoes (and sometimes peppers), Blossom End Rot—also known as BER—can be caused by:

  • A lack of calcium and magnesium—which is why it is so important to add dolomite at the start of every growing season.
  • Infrequent watering. Make sure the water reservoir never runs dry!
  • Rapid growth. This is common with plants grown in the EarthBox® gardening system because they are established in an ideal growing environment.

Solution: When fruit begins developing, check the tomatoes regularly as they grow. At the bottom of the fruit (where the yellow blossom withers up and falls off), you may start to see what looks like a dark water stain, which will start turning brown–and eventually black if not caught early enough. As soon as you see signs of BER, pick the affected fruits off and discard (once the tomato fruit is affected, it can’t be reversed and saved, so it’s best to let the plant put its energy into developing new fruit). After discarding the affected tomatoes, mix ¼ cup of hydrated lime or pickling lime with one gallon of water. Tip the system toward the overflow drain and empty the reservoir. Add the solution to the reservoir and fill as usual the following day.

As new fruit begins to set during the first 2 weeks after treatment, it could still be prone to BER, so you should continue monitoring regularly and discarding affected fruit.

Bonus Tip: Add 1 tsp. of Calcium Nitrate to the water reservoir 1 time per week to help reduce the risk of BER.

You can read more about Blossom End Rot HERE

EarthBox Tomato Gardening System Value Bundle

Now that you've read about growing tomatoes in the EarthBox gardening system, we'd like to hear from you!

Tell us in the comments below: What type of tomatoes are you growing or plan on growing this year? Do you have any tips you can share with us?