At a glance
| Pot size | 5 gal minimum for determinate, patio, and dwarf types (Iowa State allows 2 gal for cherries); larger than 5 gal for indeterminates |
|---|---|
| Potting mix | About 0.67 cu ft per 5 gal; 2 cu ft per 15 gal |
| Sun | At least 6 hours of direct sun; 6–8+ is better |
| Planting time | About 2–3 weeks after the last spring frost, once soil reaches about 60°F |
| Planting depth | Bury the stem up to the top few sets of leaves |
| Water | Check daily; once or twice a day in summer heat |
| Fertilizer | Slow-release at planting; soluble feed every 1–2 weeks once the mix's starter fertilizer runs out |
| Support | Cage or stake set while plants are small; cages at least 24 in. across |
| Time to harvest | Varies by variety; early and cherry types ripen first (check days to maturity on the tag) |
Can you grow tomatoes in pots? Which types work best
Yes. Tomatoes are one of the most rewarding container crops, provided the pot is big enough and the plant gets full sun. Iowa State University Extension and Outreach notes that determinate and dwarf types perform best in containers, that soilless potting mix beats garden soil, and that container plants dry out quickly and may need daily watering. The plant type you choose sets everything else on this page: pot size, support, and how often you water.
| Type | Growth habit | Container fit |
|---|---|---|
| Micro and hanging-basket cherries | Very small, often cascading | Excellent; small pots and baskets |
| Determinate (bush and patio types) | Stops at a set size; ripens its fruit together over a fairly short period | Excellent; the classic container choice |
| Dwarf and compact varieties | Bred to stay small | Excellent; Iowa State calls dwarf cultivars good container candidates |
| Indeterminate (vining) | Keeps growing and fruiting all season | Possible, but NC A&T notes the constant growth is hard to manage in a container; needs a large pot and tall support |
UW–Madison Extension's Milwaukee County office likewise names determinate, dwarf, and compact varieties as best suited to containers, and its list of container tomatoes includes 'Tumbling Tom' and 'Bush Early Girl'. More cultivars are covered in best tomato varieties.
What size pot for tomatoes
Bigger is almost always better; Iowa State puts it simply: the larger the container, the better. Root room matters, but the bigger reason is water: a large volume of potting mix holds a bigger water reserve, so the plant does not dry out between waterings on hot afternoons. That steadiness prevents many of the fruit problems container growers see.
| Tomato type | Extension minimum | Source |
|---|---|---|
| Cherry | 2 gal (about 10 in. across) | Iowa State |
| Standard compact or determinate | 4 gal (about 12–14 in. across) to 5 gal | Iowa State (4 gal); NC A&T, UW–Madison (5 gal) |
| Any tomato, by depth | 5 gal, 8–12 in. deep | UW–Madison Extension, Milwaukee County |
| Indeterminate (vining) | Bigger than a 5-gallon bucket | UW–Madison Extension, Marinette County |
Treat these as floors, not targets. For indeterminates especially, a much larger container holds enough water to get a big plant through a hot afternoon. A 5-gallon bucket with holes drilled in the bottom works for compact types. The site's best vegetables for containers guide gives minimums for other crops.
How much potting mix to buy
Bags of potting mix are sold in cubic feet or dry quarts. Here is what each container size takes, before settling. Buy about 10–20% extra, because fresh mix settles after the first few waterings.
| Container | Cubic feet | Dry quarts |
|---|---|---|
| 5 gal | 0.67 | 17 |
| 7 gal | 0.94 | 24 |
| 10 gal | 1.34 | 34 |
| 15 gal | 2.0 | 52 |
| 20 gal | 2.7 | 69 |
| 25 gal | 3.3 | 86 |
Container material
| Material | Pros | Cons |
|---|---|---|
| Plastic | Light, holds moisture | NC A&T notes dark colors hold heat and can damage roots in summer; choose a light color |
| Fabric grow bag | Breathable; roots air-prune instead of circling | Dries out fastest; may need water twice a day in heat |
| Terra-cotta | Heavy and stable in wind | Porous, so NC A&T notes it needs more frequent watering; heavy to move |
| Self-watering container | Built-in reservoir evens out moisture | Reservoir needs refilling; buy a large model |
| Wood half barrel | Large volume; insulates roots | Heavy; Iowa State advises cedar or redwood, never treated lumber |
Whatever you choose, it needs drainage holes. A pot with no drainage drowns the roots.
Sun and placement
Tomatoes need full sun. Iowa State's container tomato guidance calls for at least 6 hours of direct sunlight a day, and UW–Madison Extension defines full sun for tomatoes as more than 6–8 hours. On a balcony or patio, that usually means a south- or west-facing spot. North-facing balconies rarely get enough direct light for fruiting tomatoes. A wheeled plant caddy lets you chase the sun and roll the pot under cover during storms.
In very hot climates, the pot itself can overheat. Grouping containers, using light-colored pots (NC A&T's advice), or shading the sides of the pot (not the leaves) keeps the roots cooler. Iowa State adds that red color does not develop well above 90°F, so fruit ripened in a heat wave may turn yellow-orange. Long stretches of very hot days and warm nights cause flowers to drop without setting fruit, in pots or in the ground; see blossom drop on tomato and pepper.
When to plant tomatoes in pots, by zone
Tomatoes are warm-season plants. NC A&T State University Extension advises planting about two to three weeks after the last spring frost. University of Georgia Cooperative Extension cautions that warm afternoon air doesn't mean warm soil: tomatoes planted into cold ground stall, and UGA specialists recommend soil of at least 60°F before planting. Containers have an edge here: UW–Madison Extension notes container media warms up quicker than garden soil, and you can wheel the pot into a garage on a cold night.
| USDA zone | Typical window to set out container tomatoes | Notes |
|---|---|---|
| 3–4 | Late May to mid-June | Short season; choose early determinates and dwarfs |
| 5 | Mid- to late May | Pots can go out a little earlier if moved in on cold nights |
| 6 | Early to mid-May | Watch for late cold snaps |
| 7 | Late April to mid-May | Wait for nights to stay mild, not just the last frost date |
| 8 | April | Plan to shade pots in midsummer |
| 9 | February to March, plus a late-summer planting for fall | Midsummer heat can stall fruit set and coloring |
| 10–11 | Fall through late winter | Midsummer heat can stall fruit set and coloring |
The table applies the frost-plus-two-to-three-weeks rule to typical frost dates; NC A&T's own North Carolina example runs from mid-April on the coastal plain to mid-May in the mountains. These are typical ranges. Frost dates vary a lot within a zone, so look up yours with the frost date lookup.
Is it too late to plant tomatoes in pots?
Count backward from your average first fall frost. Take the days to maturity on the plant tag (counted from transplant), add about two weeks for harvesting, and add a cushion for cool fall weather, which slows ripening. If the total fits before frost, plant. In late season, choose fast cherry or early determinate varieties, which ripen sooner than large slicers.
How to plant tomatoes in a pot, step by step
- Choose the container and the variety together, using the size table above. Match an indeterminate to 15+ gallons, a patio or dwarf type to 5–10 gallons.
- Fill with fresh potting mix, not garden soil. Iowa State Extension advises a soilless potting mix: it is free of disease organisms and weed seeds, less likely to compact, and lighter than garden soil. Use a potting mix meant for containers, not seed-starting mix, which is too fine and low in nutrients for a season-long crop.
- Mix in a slow-release fertilizer at the label rate, as UW–Madison Extension suggests, unless the potting mix already includes one.
- Install the cage or stake now, before planting. NC A&T notes that waiting until plants need support makes installation difficult and can damage them.
- Plant deep. Strip the lower leaves and bury the stem so only the top few sets of leaves sit above the mix. Tomatoes root along buried stems, building a bigger root system. Leggy transplants can go in at an angle in shallower pots.
- Water thoroughly until water runs out of the drainage holes. Top up with mix if it settles.
- Harden off and place in full sun. Move indoor-started or greenhouse-grown plants outside gradually, so the leaves don't scorch.
Watering container tomatoes
Watering is where container tomatoes succeed or fail. A pot has a limited water reserve, and a big plant in July can drain it in a day. UW–Madison Extension says to check containers daily, noting that in summer plants may need water twice a day, especially in smaller containers. NC A&T and Iowa State agree that daily or twice-daily watering is sometimes needed.
| Situation | How often to check | What to expect |
|---|---|---|
| Just planted, cool weather | Every day or two | Water when the mix is dry about 2 inches down |
| Growing plant, warm weather | Daily | Often daily watering |
| Full-size plant, fruit set, hot weather | Morning and late afternoon | Once or twice a day, especially in 5-gallon pots and fabric bags |
| Self-watering container | Check the reservoir daily in heat | Fewer top waterings; keep the reservoir filled |
How to water: water at the base until it runs from the drainage holes, which wets the whole root ball. Iowa State advises avoiding wet leaves, especially late in the day, since wet foliage encourages disease. Don't let pots sit in saucers of standing water; Iowa State notes overwatering slowly kills roots by starving them of oxygen. NC A&T's test: push a finger to the second joint, about 2 inches down; if the tip is still dry, it's time.
Why consistency matters: Iowa State links inconsistent watering to fruit cracking and blossom end rot, and warns that letting the mix dry out completely can make plants drop flowers and fruit. UW–Madison Extension explains that blossom end rot is a calcium-delivery problem: a plant that dries out cannot move enough calcium to the ends of the fruit. A larger pot, a self-watering design, or a drip line on a timer smooths out those swings.
Fertilizing tomatoes in pots
Potting mix holds few nutrients, and frequent watering flushes out what is there, so Iowa State notes container tomatoes need fertilizer more often than garden plants. A schedule that follows Iowa State, UW–Madison, and NC A&T State University Extension guidance:
- At planting: a slow-release fertilizer mixed into the potting mix, unless the mix already contains one.
- After the starter charge runs out: NC A&T notes the starter fertilizer in most potting mixes is used up after two or three waterings. Iowa State recommends a soluble fertilizer (such as 15-30-15 or 20-20-20) once every week or two, applied while watering. If your mix contains a slow-release fertilizer, Iowa State says regular feeding may not be needed until midsummer.
- Before and after fruit set: NC A&T suggests a balanced fertilizer before flowering, then switching to a high-potassium fertilizer once the first fruits are about cherry-sized.
- Avoid excess nitrogen, which produces big, leafy plants with little fruit.
For product types and NPK ratios, see best fertilizer for tomatoes.
Support, pruning, and pollination in containers
Support: even compact tomatoes flop when loaded with fruit. NC A&T notes small conical cages are enough for many compact varieties. For standard-size plants, Iowa State recommends cages at least 24 inches across, made of fencing with at least 4-inch mesh so you can reach in to harvest. Indeterminates need a tall stake or heavy cage, and a wide, heavy pot so the whole thing doesn't tip in wind. One option is to drive the stake into the ground beside the pot instead of into the mix. Methods are compared in how to stake tomatoes.
Pruning: NC A&T suggests removing the suckers below the first flower cluster to reduce crowding and disease. Iowa State recommends pruning staked plants to one or two main stems to keep them manageable. The details are in tomato plant care.
Pollination: tomato flowers pollinate themselves, but pollen is released when the flower vibrates in wind or from bees. On an enclosed porch or a sheltered balcony, gently shaking the flower clusters on warm, dry mornings helps fruit set.
Container tomato problems
| Problem | Container-specific cause | Fix |
|---|---|---|
| Midday wilting, then recovery | Pot too small, or mix drying between waterings | Water more often, move to a larger pot, or add a reservoir |
| Dark, sunken spot on the fruit's bottom | Uneven moisture | Steady watering; see blossom end rot above |
| Lower leaves yellowing | Nutrients flushed out by frequent watering | Start regular liquid feeding |
| Lots of leaves, few fruits | Too much nitrogen or too little sun | Move to more sun; switch to a lower-nitrogen feed |
| Flowers drop | Heat, or a pot overheating against a wall | Shade the pot; wait for cooler nights |
| Plant tips over | Top-heavy plant in a light pot | Heavier or wider pot; anchor the stake outside the pot |
Iowa State notes that leaf spots and wilts are often less of a problem in containers, because fresh potting mix starts out free of these diseases. End of season: pull plants after frost. If the plants had disease, don't reuse that mix for tomatoes or their relatives (peppers, eggplant, potatoes) next year. Refresh or replace potting mix rather than reusing it unamended year after year.
Common mistakes
| Mistake | Why it matters | Do this instead |
|---|---|---|
| Mistake | Why it matters | Do this instead |
| Planting an indeterminate in a 5-gallon pot | It outgrows the water reserve and needs water constantly | Use a much larger container, or choose a determinate or dwarf |
| Filling the pot with garden soil | Compacts, drains poorly, and can carry disease | Use fresh soilless potting mix |
| Watering on a fixed schedule | Plant water use changes with size and heat | Check daily and water when the mix is dry about 2 inches down |
| Skipping fertilizer after planting | Frequent watering flushes nutrients out of the pot | Slow-release at planting plus regular liquid feeding after fruit set |
| Adding the stake after planting | Drives through roots; stake may be too short | Set the cage or stake before planting |
| Setting pots out on the first warm day | Cold soil and cold nights stall growth | Wait 2–3 weeks past the last frost; move pots inside during cold snaps |
Frequently asked
How often should you water tomatoes in pots?
Check daily, and water when the potting mix is dry about 2 inches down. In hot weather, a full-size plant, especially in a smaller pot or fabric bag, may need water twice a day. Water until it drains from the bottom so the whole root ball is wet.
What size pot do tomatoes need?
Extension minimums run from 2 gallons for cherry tomatoes (Iowa State) to 4–5 gallons for compact standard types, and more than 5 gallons for indeterminates (UW–Madison Extension). Larger containers hold more water and buffer the plant against drying out, so go bigger when you can.
Can you grow indeterminate tomatoes in pots?
Yes, in a container much larger than 5 gallons with a tall stake or heavy cage. Expect daily watering in summer, and prune staked plants to one or two main stems, as Iowa State recommends. Compact determinate or dwarf varieties are easier in smaller spaces.
How long does it take to grow tomatoes in pots?
It depends on the variety: check the days to maturity on the plant tag or seed packet, which is counted from transplanting. Early varieties and cherry types ripen first. Starting from seed adds four to six weeks of indoor growing before the plant reaches transplant size, per NC A&T.
How deep should you plant tomatoes in pots?
Bury the stem so only the top few sets of leaves are above the potting mix, after removing the lower leaves. Tomatoes grow roots along buried stem sections, which builds a stronger root system. In a shallow pot, lay a leggy stem at an angle instead.
How often should you fertilize tomatoes in pots?
Mix a slow-release fertilizer into the potting mix at planting. Iowa State recommends a soluble fertilizer every week or two, though mixes containing slow-release fertilizer may not need it until midsummer. Container plants need more regular feeding than garden tomatoes because they have less soil to draw nutrients from.
How do you support tomato plants in pots?
Put a sturdy cage or stake into the pot at planting time, while the plant is small. Iowa State recommends cages at least 24 inches across for standard-size plants; use a tall support for indeterminates and a wide, heavy pot so the plant does not tip over. Tie stems loosely to the stake as they grow.
Is it too late to grow tomatoes in pots?
Add the variety's days to maturity, plus about two weeks of harvest time, to today's date, and compare the result with your average first fall frost. If it fits, plant a fast cherry or early determinate. In the warmest zones, late summer is a common time to plant for a fall crop.
Sources
- Growing Tomatoes in Containers, Iowa State University Extension and Outreach
- Container Vegetable Gardening (PM 870B), Iowa State University Extension and Outreach
- Growing a Tomato Plant in a Container, University of Wisconsin–Madison Extension, Marinette County
- Growing Fruiting Vegetables in Containers: Tomato, Pepper and Eggplant, N.C. A&T State University Cooperative Extension
- Best Container Gardening Vegetable Varieties, University of Wisconsin–Madison Extension, Milwaukee County
- Warm Air Doesn't Mean Warm Soil, University of Georgia Cooperative Extension, Evans County