Tips for Growing Container Tomatoes

Use this 12-step program for growing success.
'Jet Star' Tomato

'Jet Star' Tomato

Give container tomatoes the support of stakes, teepees or wire cages for supporting the weight of the fruit on limber vines.

Give container tomatoes the support of stakes, teepees or wire cages for supporting the weight of the fruit on limber vines.

There are so many advantages to growing tomatoes in containers until it almost seems a like a no-brainer. You get to control the growing conditions, more easily protect plants from pesky insects and disease, and enjoy the fruits of your labor by barely stepping outside. 

Yet, there are definitely some things to keep in mind for helping ensure success at growing this favorite edible. Here are 12 tips:

  1. Select healthy plants. Plant the largest you can find.  Any variety that grows in the ground can be grown in a pot, but some stand out more than others. Consider ‘Brandywine’, ‘Sungold’, ‘Bush Early Girl’, ‘Silvery Fir Tree’, ‘Cherokee Green’  and ‘Sweet Pea’ to name a few.
  2. Choose a large container – the bigger the better. Container soil heats up and dries out quicker than garden soil because of the confinement, so the more breathing room you can give the plant’s roots the better. Choose a pot that’s at least 18-20 inches in diameter and holds at least 15 gallons.  Avoid terra cotta pots, which retain heat and are heavy to move around, and half whiskey barrels, which, though large, also are burdensome and attract wood roaches. Instead, choose lightweight plastics with drain holes.
  3. Position the container in full sun. Tomatoes perform best when they receive six to eight hours of sun per day. 
  4. Use a potting soil rich in organic matter. Or replace about 25 percent of standard potting soil with equal parts perlite, sphagnum peat moss and compost to improve drainage and provide additional nutrients. Add a 1- to 2-inch layer of pebbles in the bottom of the pot to help with drainage.
  5. Mix slow-release fertilizers into the soil. Make sure the soil doesn’t already include it; if it does not, choose tomato-specific fertilizers such as Espoma, though all-purpose ones are effective as well.
  6. Plant the tomato deeply.  Fill the pot one-third with soil and then plant the tomato. Continue adding soil, packing it around the stem of the plant until it is about half covered,  removing any leaves as you go.
  7. Water the plant thoroughly. Then a few minutes later, water again so that the roots get soaked. Wait a week before watering again.
  8. Water consistently.  That’s the key to growing tomatoes. They prefer moist, but not wet, soil. This requires checking the soil every day. Water in the morning, when plants take up and use water more efficiently, wetting the soil – not the plant. Top the soil with an inch or two of mulch to help it retain moisture. If using a saucer, never leave plants sitting in standing water because they continue to take up the moisture.
  9. Give tomato plants growing support. Stake them or install a tomato cage (or build your own out of concrete reinforcing wire) for helping take the weight of the fruit off limber vines.
  10. Feed plants once a week starting in week six. Choose a water-soluble fertilizer and apply according to instructions, and keep an eye out for pests, such as aphids.
  11. Add companion plants only if there’s room. Ornamental annuals such as marigolds and zinnias make pretty accents in a tomato container garden, but remember that additional plants compete with tomatoes for water so add them only if using an oversized pot.
  12. Harvest tomatoes once they are nearly completely red.  This helps ensure the freshest, tastiest fruit.