Tomato Plants: Care and Growing Guide

What are tomato plants?

Tomatoes (Solanum lycopersicum) are warm-season annual vegetables grown in every US state. They need 6–8 hours of direct sun, warm soil above 60°F, consistent moisture, and structural support as they grow. With the right setup, a single plant produces 10–30 pounds of fruit per season depending on variety.

The USDA reports that more than 86% of American home gardeners grow tomatoes — making them by far the most popular homegrown vegetable. This is partly because homegrown tomatoes taste dramatically better than store-bought: tomatoes lose flavor compounds rapidly after harvest due to cold chain storage, while home-harvested fruit reaches peak flavor on the vine.

This guide covers the full lifecycle of growing tomatoes in the US — from choosing varieties to transplanting, feeding, staking, watering, and solving common problems.

Choosing tomato varieties

Selecting the right variety is the most important decision before planting. Tomatoes fall into three broad categories by growth habit and two categories by fruit type.

Determinate vs. indeterminate tomatoes

Determinate tomatoes grow to a fixed height (typically 2–4 feet), set all their fruit within a 2–3 week window, and stop growing. They are ideal for canning, sauce-making, or gardeners who want one large harvest. Examples: Roma, Celebrity, Bush Early Girl, Better Bush.

Indeterminate tomatoes keep growing taller all season (often 6–10 feet) and produce fruit continuously until frost. They provide a steady supply of tomatoes from summer through fall. They require more staking and more pruning. Examples: Cherokee Purple, Brandywine, Sun Gold, Better Boy.

For a guide to one of the most popular indeterminate types, see our indeterminate tomatoes guide.

Tomato variety comparison

For specific variety deep dives, see our guides on Better Boy tomato, Super Sweet 100, Cherokee Purple tomato, and Sun Gold tomato.

When to plant tomatoes in the US

Plant tomatoes after the last frost date in your area, when soil temperature is consistently above 60°F. Cold soil stunts early growth and delays fruiting significantly.

US planting timing by zone:

• Zone 9–10: February–March
• Zone 7–8: Mid-March to mid-April
• Zone 6: Late April to early May
• Zone 5: Mid-May to late May
• Zone 4–3: Late May to early June

Soil temperature matters more than air temperature. A soil thermometer costs $8–12 at most garden centers. Tomatoes planted in soil below 55°F may survive but grow very slowly for 2–4 weeks until soil warms. Plants transplanted 2 weeks later into warmer soil often catch up within a month.

For hardiness zone information specific to your area, the planting zones guide covers all 13 USDA zones with frost dates by state.

How to plant tomato transplants

Plant tomatoes deep — bury up to two-thirds of the stem in the soil. New roots form along the buried stem sections. A tomato plant buried with 10 inches of stem develops a larger root system than one planted at soil level, giving it better drought resistance and nutrient access.

Planting steps

1. Dig a hole deeper than the root ball — large enough to bury two-thirds of the plant’s stem
2. Remove all leaves from the portion of stem that will be buried
3. Set the transplant at an angle in the hole if the stem is very long (a trench works well for leggy transplants)
4. Backfill with native soil mixed with compost
5. Water thoroughly at planting: at least 1 gallon per plant
6. Install your stake or cage at planting time — placing it after plants are established disturbs roots and may damage them

Spacing: 18–36 inches between determinate types; 24–48 inches between indeterminate types. Wider spacing improves air circulation and reduces fungal disease pressure.

Mulch: Apply 2–3 inches of straw, wood chips, or compost around the base after planting. Mulch maintains soil moisture, moderates soil temperature, and prevents soilborne diseases from splashing onto lower leaves.

Sun and location requirements

Tomatoes need 6–8 hours of direct sun per day. Full sun (8 hours) produces significantly more fruit than the 6-hour minimum. South-facing beds or slopes are ideal in most US climates.

In the Southeast (Zone 7–9), a site with morning sun and light afternoon shade can reduce heat stress during peak summer. Temperatures above 95°F for extended periods reduce fruit set because pollen becomes non-viable above 90°F. Brief afternoon shade prevents this in the hottest regions.

In northern gardens (Zone 4–5), maximize sun exposure by placing tomatoes on south-facing beds away from shade from buildings or trees. Every extra hour of sun accelerates maturity in short-season climates.

Watering tomato plants

Water tomatoes 1–2 inches per week. Deep, infrequent watering encourages roots to grow deep. Shallow daily watering produces a shallow root system that is more vulnerable to drought and temperature stress.

A practical watering schedule for most US climates during summer: water deeply twice weekly, delivering 0.5–1 inch per session. Use a rain gauge or a tuna can to measure actual rainfall and supplemental watering combined.

Watering problems:

Irregular watering is the primary cause of two common tomato disorders:

• Blossom end rot: Black, leathery patches on the bottom of fruit. Caused by calcium deficiency due to inconsistent water supply — the plant cannot move calcium without consistent moisture.
• Fruit cracking: Circular or radial cracks on ripe fruit. Caused by rapid water uptake after a dry period — the fruit skin can’t expand fast enough.

Drip irrigation systems solve both problems by delivering consistent moisture. Even a simple soaker hose on a timer works well. Overhead watering with a sprinkler increases fungal disease pressure because wet foliage is the entry point for early blight, late blight, and Septoria leaf spot.

Feeding tomatoes

Tomatoes are heavy feeders but require different nutrients at different growth stages. Too much nitrogen early causes lush leafy growth with little fruit; too little calcium causes blossom end rot.

Fertilizing schedule:

At transplanting: work a balanced fertilizer (10-10-10 or similar) into the planting hole at the rate specified on the label. Alternatively, use a handful of bone meal for phosphorus and compost for organic matter.

When first flowers appear: switch to a lower-nitrogen fertilizer (such as 5-10-10) or a tomato-specific fertilizer. Excess nitrogen at this stage produces leaves instead of flowers.

Every 2–3 weeks through the season: continue with the tomato fertilizer at the label rate.

For calcium supplementation: if blossom end rot appears, foliar spray with calcium chloride solution (available as a ready-to-use product) or improve watering consistency, which addresses the underlying delivery problem. Ground limestone or gypsum can be worked into the soil around plants for slow-release calcium.

Our tomato fertilizer guide covers nutrient management in detail, including organic options and soil amendment timing.

How to stake and support tomatoes

Install support at transplanting time, before plants need it. Stakes driven into the soil after tomatoes are growing risk damaging root systems that extend 12–24 inches from the stem.

Support options by plant type:

Determinate varieties (compact, 2–4 feet):

• Standard wire cage (4 feet tall): sufficient for most determinate types
• Single stake (4–5 feet): tie main stem every 6–8 inches as it grows

Indeterminate varieties (tall, 5–10+ feet):

• Heavy-gauge metal cage (5–6 feet): tomato cages designed for indeterminate types, not the flimsy standard ones
• Single stake (6–8 feet): pound 18 inches into the ground; use soft ties to attach the stem every 8–10 inches
• Florida weave (for multiple plants in rows): use twine run horizontally between stakes every 12 inches to support multiple plants with less staking hardware

The most common mistake is using undersized cages for indeterminate tomatoes. A standard 4-foot tomato cage collapses under an indeterminate variety by late summer. For large-growing types, use a 5–6-foot heavy-gauge cage or stake with an 8-foot wooden or metal stake.

Pruning tomato plants

Pruning (removing suckers) is necessary for indeterminate tomatoes to manage size and improve fruit quality. Determinate tomatoes should not be pruned — removing growth reduces their single harvest.

A sucker is a new stem that grows from the junction between the main stem and a leaf branch. Left to grow, each sucker becomes a full secondary stem with its own suckers. Unpruned indeterminate tomatoes become a thicket of stems that are difficult to support, prone to disease, and produce smaller fruit.

For indeterminate types, remove suckers when they are 1–2 inches long by pinching or snapping them off with your fingers. At this size, the wound heals quickly. Larger suckers should be removed with clean pruning shears.

A single-stem or two-stem training system is most common for indeterminate tomatoes:

• Single stem: Remove all suckers; train one central stem up a stake
• Two-stem: Allow one sucker (the first below the first flower cluster) to grow; remove all others

Our how to prune tomatoes guide covers sucker removal in detail with the timing and technique for each approach.

Common tomato plant problems

For troubleshooting yellow foliage specifically, our yellow leaves on tomato plants guide covers all causes with photos and remedies.

Pests to watch for

Hornworms: Large green caterpillars that can defoliate a plant in days. Hand-pick them; look for frass (black droppings) on leaves as the first sign. Bt (Bacillus thuringiensis) spray controls them.

Aphids: Cluster on growing tips and undersides of leaves. Knock off with strong water spray; insecticidal soap as needed.

Stinkbugs: Brown bugs that pierce fruit and leave white, corky spots inside. Difficult to control organically; row cover during vulnerable periods helps.

Growing tomatoes in containers

Tomatoes grow well in containers, giving gardeners without ground space access to a full tomato harvest. The key constraints are pot size and water frequency.

Minimum container size:

• Determinate/compact types: 5-gallon minimum, 10-gallon preferred
• Indeterminate types: 15-gallon minimum, 25-gallon preferred

Container plants dry out faster than in-ground plants. In summer heat, a container tomato may need watering once or twice daily. Self-watering containers dramatically reduce this maintenance burden by holding a water reservoir the plant draws from.

Our how to grow tomatoes in pots guide covers container-specific soil mixes, fertilizing frequency, and variety selection for pots.

Companion planting with tomatoes

Several companion plants have documented benefits for tomatoes:

• Basil: Repels aphids and thrips; may improve tomato flavor (anecdotal but consistent in gardener reports)
• Marigolds: Deter root-knot nematodes in soil; repel aphids and whiteflies
• Borage: Attracts beneficial insects; deters tomato hornworm
• Parsley and dill (when flowering): Attract parasitic wasps that prey on hornworm eggs

Plants to avoid near tomatoes: fennel (inhibits most vegetable growth), corn (shares some pests, including earworm that also attacks tomatoes).

For a full companion planting guide, our tomato companion plants guide covers 12 companions with tested results and spacing recommendations.

Harvesting tomatoes

Harvest tomatoes when they reach full color for their variety and yield slightly to gentle pressure. Never refrigerate fresh tomatoes — refrigeration below 55°F breaks down flavor compounds and changes texture within 24 hours.

Signs of ripeness:

• Full color reached (red, yellow, purple, orange — whatever the variety color is)
• Fruit yields to gentle thumb pressure without collapsing
• Fruit detaches easily with a gentle twist

You can harvest tomatoes at “breaker stage” — when they have begun to change color but aren’t fully ripe — and ripen them indoors at 65–70°F. This protects fruit from birds and chipmunks and is useful for the end-of-season rush before first frost.

If frost is coming, harvest all tomatoes showing any color change. They will ripen indoors. Fully green tomatoes will not ripen successfully indoors — they can be used for fried green tomatoes or green salsa.

For how far apart to plant tomatoes for optimal spacing and airflow, see our tomato spacing guide.