QUESTION: I want to grow tomatoes in containers, but I’ve never done it before, and I’m not sure how they’ll do. Do tomatoes grow well in containers? — Thomas G.
ANSWER: If you choose the right variety, tomatoes can grow quite happily in containers. There are just a few guidelines you should follow to cultivate your own tomatoes in containers. If you follow the instructions below, your tomato plants will grow healthy and strong in containers, yielding a hefty harvest. Here’s what you need to know.
Situate your containers in a spot with plenty of sunshine.
Your tomato plants need to get full sun so they will perform well. “Full sun” means the plants must get between six and eight hours of direct sunlight each day to perform well. Don’t try to skimp on the sunshine—tomato plants need plenty of sunlight and warmth to produce flowers and tomatoes.
Watch your garden to see how sunlight moves across it. You can make a diagram if you need to so you can keep track of how much sunlight the different areas in your garden get. You should monitor the sunlight in your garden a few times a year, because it changes.
For the heftiest yield, position your tomato plants in a spot where they will get at least eight hours of sunshine. If sunlight is sparse in your garden, you can grow cherry tomatoes somewhere that gets four to five hours of sunshine. However, you should know that the harvest will be lighter than it would have been if the plant received full sun.
Because tomatoes thrive in warm weather, they don’t do so well when it’s chilly. If the temperature in your area falls under 50 degrees Fahrenheit (10 degrees Celsius), you should bring your tomato plants indoors or to a sheltered area like a shed or garage. If the temperature climbs above 90 degrees, you may notice that flowers no longer appear and the tomatoes do not grow to full size and ripen.
Choose the right containers for your tomato plants.
Tomato plants have deep roots, so they must have a container large enough to allow them to develop a strong, healthy root system. The pot you will use to grow tomatoes must be at least 24 inches wide and 24 inches deep.
Another guideline you can use to select a container is that the pot must be able to hold at least 15 gallons of potting soil. Smaller containers will quickly dry out in the summer sun, requiring you to water them frequently and causing needless stress on your tomato plant. Stress can make plants more susceptible to diseases and other problems.
The pot you choose absolutely must have drainage holes in the bottom. You may hear some gardeners say that you can use containers without drainage holes if you line the bottom of the pot with broken pottery or rocks. This is simply untrue. You can find out more about why containers you will use in the garden must have drainage holes in our article Do You Need Holes in Your Plant Pots?
Place a layer of mesh at the bottom of your container before adding soil and the tomato plant. The mesh will let water pass through without taking the soil with it. If you notice that soil is still slipping out of your plant pot with the water, you can add another layer of mesh to keep it in place. Mesh made to use as a window screen works well for this.
Bolster Your Tomato Plants With a Stake or Other Support
If your tomato plants are indeterminate, they will need a stake or another kind of support. If you aren’t sure how to tell the difference between determinate and indeterminate tomato plants, you can refer to our article Determinate (Bush) Vs. Indeterminate (Vine) Tomatoes, Explained.
Determinate tomatoes will still need supporting, but you can use a smaller cage, shorter trellis, or shorter stake for them. To avoid damaging the root system of your tomato plants, set up the stake or cage before you plant the tomatoes. About once a week, make sure the main stems of your tomato plants are connected to the support system. If not, loosely tie the stem to the stake or other support with garden ties or twine.
Most tomato varieties will need some kind of support. However, if you are growing tomatoes that spill out of a hanging basket or a very compact variety, you can skip the stakes.
Keep Moisture in the Soil with Compost or Mulch
Without a protective layer of compost or mulch, the soil in a container dries out much more quickly than the soil in your garden. Save yourself extra watering trips and make sure your plants get the hydration they need by using compost or mulch on top of the soil.
You’ll need to add a layer of compost or mulch that’s between two and four inches deep around your tomato plants in their containers. Make sure not to let the compost or mulch touch the plants. They need a few inches of empty space around them to keep plant diseases from moving easily through your garden. If you aren’t sure whether to use compost or mulch, you can read our article Compost Vs. Mulch: What’s the Difference.
Give Your Tomato Plants in Containers Plenty of Water
Tomatoes in containers might require water as frequently as twice per day when the temperature rises. There’s a simple test you can use to determine whether it’s time to water your tomatoes. Insert your finger into the soil to a depth of two inches. If the soil sticks to your skin or feels moist to the touch, it’s not yet time to give your tomato plants water. You’ll notice that plants growing in larger containers need water less frequently than those in smaller pots.
If your plant’s foliage is wilting even though the soil has plenty of moisture, don’t fret. The plant conserves moisture when it needs to by allowing the leaves to wilt. However, more extensive wilting that happens when the soil has dried out means your plant is suffering the consequences of dehydration. This not only makes your plant susceptible to stress—it can cause the disease blossom end rot. If your watering schedule has been inconsistent, you may also see issues such as cracking or splitting.
When you water your plants, aim the water at the base of the plant so it can be absorbed by the roots. The tomato plant cannot use water that falls on its foliage—not to mention, if water splashes onto the foliage, it can cause problems such as blight or fungus.
Nourish Your Tomato Plants With Fertilizer
Even if the potting mix you used to plant your tomatoes says it includes a slow-release fertilizer, you’ll still need to fertilize your tomato plants. Every two or three weeks is a good schedule for adding fertilizer. Your tomato plants need this nutrition most when they’ve started to produce flowers. Use an all-purpose water-soluble fertilizer or liquid organic fertilizer. There are also fertilizers made especially for tomatoes that you can use.
You can tell when it’s time to fertilize your tomato plants by checking the color of the foliage. A tomato plant that’s getting plenty of nutrition has dark green leaves, but the color will turn lighter if fertilizer is needed.
Bury the Stem for a Well-Developed Root System
When you move your tomato plant into its container, you have an opportunity to help it grow an extensive root system, which keeps the plant supplied with moisture and nutrients. Clip off the bottom few leaves or small stems. Then place the tomato plant in the hole you’ve made, burying the stem so that the spots where you clipped a leaf are under the surface of the soil. The plant will send out roots from those places.
Fend Off Insects With Netting
If larger insects like tomato hornworms, caterpillars, and stinkbugs are an issue in your garden, black netting can be a solution. It won’t keep off smaller bugs like aphids or whiteflies, but it’s effective against larger pests.
Each container will need two yards of black netting (each 72 inches wide). Put the netting around the outside of the wire cage in your container. You can use clothespins to clip the netting to the wire cage at the top. To keep the top closed, you’ll need some large, heavy-duty rubber bands.
Select the Right Tomato Varieties for Containers
Not all tomato plants will thrive in containers, so it’s imperative that you get a variety that will perform well in the smaller space. Check the seed packet or online product description to find the estimated mature size of the plant. Smaller varieties are a safer bet than larger ones, though you can grow plants that will stretch to seven feet tall if you use a five-gallon to seven-gallon container.
Here’s a list of tomatoes that gardeners recommend for container gardening:
- Ace 55 Hybrid
- Bartelly F1
- Better Bush Hybrid
- Big Boy Bush Tomato
- Bing Cherry
- Black Cherry
- Black Krim
- Black Plum
- Black Seaman
- Bush Champion
- Bush Early Girl Hybrid
- Bush Goliath Tomato
- Bush Steak
- Clear Pink Early
- Czech’s Bush
- Defiant PhR
- Early Cascade
- Early Girl Bush
- Golden Nugget
- Green Grape
- Green Zebra
- Grosse Lisse
- Health Kick Hybrid
- Husky Red
- Indian Stripe
- Japanese Black Trifele
- Jet Star
- Merisol Red
- Micro Tom
- Moby Grape
- Mortage Lifter
- Mountain Gold
- New Yorker
- Oregon Spring
- Paul Robeson
- Patio F1 Hybrid
- Patio Pik
- Pik Red
- Plum Regal
- Polish Linguisa
- Principe Borghese
- San Marzano
- Silver Fir Tree
- Small Fry
- Solar Fire Hybrid
- Sophie’s Choice
- Sunrise Sauce
- Sun Sugar
- Sweet Baby Girl
- Sweet 100
- Sweet Million
- Talladaga Hybrid
- Tappy’s Finest
- Tasmanian Chocolate
- Terenzo F1
- Tidwell German
- Tidy Treats
- Tiny Tim
- Tumbling Tom
- Window Box Roma