How To Care For Tomato Plants

Estimated reading time: 7 minutes

Learning how to care for tomato plants is one of the most rewarding skills a home gardener can pick up. A little attention to watering, feeding, pruning, and pest control goes a long way. It can turn a few small seedlings into baskets of juicy, homegrown tomatoes. Here’s everything you need to know to keep your plants thriving from planting day to harvest.

Choosing the Right Type of Tomato Plant

Before you get into the details of how to care for tomato plants, it helps to know what kind you’re growing. This is important, since that affects almost every decision down the line. Tomatoes generally fall into two growth habits:

• Determinate (bush) varieties stop growing at a set height and produce their fruit in one concentrated flush. They’re a great fit for containers or tight garden spaces.
• Indeterminate (vining) varieties keep growing and producing all season long. Therefore, this makes them better suited to larger gardens where you want a steady, extended harvest.

Within those two categories, you’ll find everything from bite-sized cherry and grape tomatoes to hefty beefsteaks. There are also meaty paste tomatoes like Roma that are perfect for sauce, as well as heirloom varieties prized for their unusual colors and flavors. Moreover, you will find modern hybrids bred for disease resistance and heavy yields.

Getting Off to a Strong Start: Planting

A healthy root system is the foundation of a healthy plant, so it’s worth taking your time here. If you’re container gardening, choose a pot at least 9 inches across and fill it with a well-draining mix. It should be roughly equal parts loam and soil-based compost. You should boost it with organic matter to help the soil hold moisture without staying soggy.

When you set the seedling in the ground or pot, plant it deeper than you might expect. It should be right up to the first set of leaves. Tomato stems can grow roots wherever they touch soil. So, burying more of the stem builds a stronger, more extensive root system before the plant even starts producing.

Staking and Support

Part of knowing how to care for tomato plants is planning for how big they’ll get. Indeterminate varieties can reach 6 feet or more and need sturdy support from early on:

• Drive a tall, strong stake or cane into the soil at planting time, being careful not to disturb the roots. Then tie the stem to it loosely with a figure-eight knot as it grows to avoid crushing the stem.
• Alternatively, many gardeners train vining tomatoes up a length of sturdy garden twine. They wind the stem around it as it climbs.

Determinate (bush) tomatoes usually don’t need staking. However, a little extra support under heavy branches can keep them from snapping once the fruit gets heavy.

Watering the Right Way

Tomatoes want consistently moist soil. Letting the soil dry out and then drenching it can cause the fruit to split. In addition, uneven watering paired with low calcium levels can trigger blossom-end rot, where the bottom of the fruit turns dark and sunken.

The fix is a steady watering routine: frequent, moderate watering rather than occasional heavy soaks, especially during hot spells. A classic trick is to bury an upturned plastic bottle (bottom cut off) in the soil next to the plant and pour water directly into it. This sends moisture straight to the roots, cuts down on surface evaporation, and doubles as an easy way to deliver liquid fertilizer.

Feeding for Bigger, Juicier Fruit

Tomatoes are sun-lovers that also need the right nutrients to fruit well. Feed with a liquid tomato fertilizer (look for one higher in potassium) every two to three weeks through the end of summer. Once you hit early fall, switch to a general, nitrogen-rich fertilizer. This keeps the foliage strong and productive as the season winds down.

Weed Control

Weeds compete with tomatoes for water and nutrients, so keep the area around the stems clear. A 3-4 inch layer of mulch helps suppress weeds and locks in soil moisture. In addition, some gardeners also sow crimson clover as a living ground cover once plants reach about 2 feet tall. It chokes out weeds while adding nitrogen back into the soil.

Pruning and Pinching Out

For indeterminate (vining) varieties, regularly pinch out the side shoots (suckers) that form between the main stem and branches. Bend each shoot until it snaps cleanly rather than leaving a stub, which can die back and invite disease. Determinate (bush) varieties should generally be left alone. Removing side shoots on these can cut your total yield.

Once an indeterminate plant has set four trusses of fruit outdoors (or six indoors), pinch out the growing tip. This encourages the plant to put its energy into ripening what it already has. Some gardeners also strip leaves below the lowest fruit truss to improve airflow and reduce disease pressure. However, this is a matter of some debate among growers, so use your judgment based on your own conditions.

Managing Pests and Disease

A well-rounded pest and disease strategy is essential to any tomato plant care routine. Watch for common threats like fungal diseases, Fusarium and verticillium wilt, late blight, flea beetles, hornworms, fruitworms, and tobacco mosaic virus. Reduce risk by:

• Using organic or targeted chemical controls as needed
• Spacing plants properly for good airflow
• Rotating crops each season
• Choosing disease-resistant varieties where possible
• Inspecting plants regularly and removing infected ones promptly

Frequently Asked Questions About Caring for Tomato Plants

How often should I water my tomato plants? 

Most tomato plants need watering two to three times a week, more often during hot, dry stretches. The goal is consistently moist soil, not a cycle of drying out and then soaking. That swing is what causes cracked fruit and blossom-end rot.

How do I know if my tomato plant is getting too much or too little water? 

Wilting leaves that perk back up in the evening usually just mean the plant is stressed by heat, not thirst. Leaves that stay droopy, yellow, or curl under are a better sign of a watering problem. Check whether the soil a couple of inches down is bone dry (underwatered) or waterlogged (overwatered).

Do all tomato plants need to be staked? 

No. Indeterminate (vining) varieties need staking or another support system because they keep growing taller all season. Determinate (bush) varieties are more compact and usually don’t need staking, though a little support can help once the fruit gets heavy.

How often should I fertilize tomato plants? 

Feed with a liquid tomato fertilizer every 2-3 weeks through the end of summer, then switch to a general, nitrogen-rich fertilizer in early fall to support the foliage as the season winds down.

Why are the bottoms of my tomatoes turning black? 

That’s blossom-end rot, usually caused by inconsistent watering combined with a calcium shortage in the soil. A steady watering schedule is the most effective fix.

Should I remove the lower leaves and side shoots? 

For indeterminate varieties, yes. Pinch out side shoots (suckers) regularly so the plant puts its energy into fruit rather than extra foliage. Removing leaves below the lowest fruit truss can improve airflow, though opinions vary on how much it helps, so it’s worth experimenting with your own plants. Determinate varieties should generally be left unpruned.

How can I keep pests and disease away from my tomato plants? 

Space plants for good airflow, rotate where you plant tomatoes each year, choose disease-resistant varieties when you can, inspect plants regularly, and remove any infected plants right away before problems spread.

When are tomatoes ready to pick? 

Most varieties are ready when the fruit reaches full color and gives slightly to gentle pressure. If frost is approaching, you can pick tomatoes while still green and let them ripen indoors on a sunny windowsill.

Once you’ve got the basics of how to care for tomato plants down, you’ll be rewarded with a season full of ripe, flavorful tomatoes. These will come straight from your own backyard or patio.