Plant tomatoes in a pot with at least 5 gallons of soil, one plant per container, in a spot that gets six to eight hours of direct sun daily

Container tomatoes need more frequent watering and feeding than garden tomatoes because the soil dries faster and nutrients wash out with each watering. A 5-gallon pot is the practical minimum for most varieties; larger pots (10 to 20 gallons) reduce how often you water and give roots more room to spread. The pot must have drainage holes in the bottom — without them, water pools around the roots and causes rot within days.

Tomatoes are heavy feeders and heavy drinkers in pots. You will water more often than you expect, especially once fruit sets and the plant is in full growth. The soil itself matters more in a pot than in the ground because it is all the plant has to draw from.

Key Takeaways

  • Use a pot at least 5 gallons in size with drainage holes, filled with potting soil (not garden soil), and place it where the plant gets six to eight hours of direct sun each day.
  • Plant one tomato per pot, burying the stem deeper than it was growing in the nursery pot so roots form along the buried stem.
  • Water when the top inch of soil feels dry, which in summer heat may be every day or every other day.
  • Feed every two to three weeks with a balanced fertilizer once the plant flowers, or use a slow-release fertilizer mixed into the soil at planting time.
  • Stake or cage the plant at planting time so you do not damage roots later by driving a stake through them.

Choosing the right pot and soil

The pot size determines how much you water and how large the plant grows. A 5-gallon bucket or nursery pot works, but ceramic or fabric pots are easier to move and look better on a patio. Avoid pots smaller than 5 gallons — they dry out too fast and the plant stays stunted. If you grow a large indeterminate variety (one that keeps growing all season), a 10 to 20-gallon pot gives better results.

Use potting soil, not garden soil or topsoil. Potting soil is light, drains well, and contains peat moss or coco coir to hold moisture without waterlogging. Garden soil compacts in a pot and stays soggy. Fill the pot to within an inch of the rim so water does not run straight off the top.

Planting the seedling or transplant

Tomato seedlings from a nursery are usually 6 to 12 inches tall and have several true leaves. Remove the plant from its nursery pot and loosen the root ball gently with your fingers. Bury the stem deeper than it was growing before — tomatoes form roots all along the buried stem, which creates a stronger root system. You can bury it up to the first set of true leaves if the seedling is leggy (tall and thin).

Set the plant in the center of the pot, fill around it with potting soil, and press gently so the soil makes contact with the roots. Water when ready after planting until water drains from the bottom. This settles the soil and removes air pockets.

Sunlight and location

Tomatoes need six to eight hours of direct sun each day to flower and fruit well. Less sun produces fewer tomatoes and more disease. A south-facing patio or balcony is ideal in most climates. If you have only four to five hours of direct sun, the plant will still grow but will flower later and produce less fruit.

Place the pot where it will not blow over in wind — a sheltered corner or against a wall helps. Avoid placing it directly against a hot wall in intense climates, as the reflected heat can stress the plant. If you live in a very hot climate (above 95°F regularly), afternoon shade helps prevent the flowers from dropping.

Watering and feeding

Water when the top inch of soil feels dry to your touch. In summer heat, this may be every day. Stick your finger into the soil — if it is moist an inch down, wait another day. Inconsistent watering causes problems: too little and the plant wilts, too much and roots rot. Blossom end rot (a dark spot on the bottom of the fruit) is often caused by uneven watering, especially when the plant flowers and sets fruit.

Tomatoes in pots need feeding because nutrients leach out with each watering. Once the plant flowers, feed every two to three weeks with a balanced fertilizer (such as 10-10-10) or a tomato-specific formula. Follow the label rate — too much fertilizer burns roots and produces leafy plants with few tomatoes. Alternatively, mix a slow-release fertilizer into the potting soil at planting time; it feeds gradually over the season and requires no additional feeding.

Supporting the plant with stakes or cages

Install a stake or cage at planting time, before the roots spread. A wooden stake, bamboo pole, or metal cage all work. Determinate varieties (bush types that stop growing at a set height) need light support. Indeterminate varieties (vining types that grow all season) need sturdy cages or stakes at least 4 to 5 feet tall.

Tie the stem loosely to the stake with soft ties or strips of cloth as it grows. Avoid tying too tight, which cuts into the stem. If you wait to stake the plant until it is already tall, you risk driving the stake through roots and damaging them.

Common problems in containers

Yellowing lower leaves are normal as the plant grows — remove them to improve air flow. Wilting in the afternoon that recovers by evening is usually just heat stress and not a sign of underwatering. Wilting that does not recover means the soil is too dry or the roots are rotting from too much water.

Pests like spider mites and whiteflies thrive in hot, dry conditions. Spray the undersides of leaves with water to dislodge them, or use insecticidal soap if the infestation is heavy. Diseases like early blight (brown spots on lower leaves) spread in humid conditions — remove affected leaves and improve air circulation by spacing pots apart.

Frequently Asked Questions

Can I use a pot without drainage holes if I am careful with watering?

No. Even careful watering leaves standing water at the bottom, and roots rot within a week or two. Drainage holes are not optional — they are essential. If you like the look of a pot without holes, use it as a decorative outer pot and set a draining pot inside it.

How often should I water in winter or cool weather?

Much less often than in summer. In cool weather, soil dries slowly. Check the soil before watering — it may need water only once or twice a week. Overwatering in cool weather is a common cause of root rot because the plant is not actively growing and does not use much water.

What size pot do I need for a cherry tomato versus a beefsteak tomato?

Cherry tomatoes are smaller plants and do well in 5-gallon pots. Beefsteak and other large varieties need 10 to 20-gallon pots because they grow taller and produce heavier fruit. A beefsteak in a 5-gallon pot will produce fruit, but the plant stays smaller and yields less.

Can I move a potted tomato plant once it is growing?

Yes, but minimize the move. If you must relocate it, do so on a cloudy day or in the evening so the plant does not wilt from the stress. Water it well before moving. Avoid moving it repeatedly, as each move stresses the roots.

Should I remove the bottom leaves as the plant grows?

Yes, once the plant is established. Remove leaves that touch the soil or show spots or yellowing. This improves air flow, reduces disease, and directs the plant's energy into fruit rather than maintaining old foliage. Stop removing leaves once the plant is flowering heavily, so you do not expose developing fruit to sunburn.