🍅 When to Plant Tomatoes

Tomatoes are America’s most popular garden vegetable, and for good reason: few crops reward a little attention with this much fruit. They’re warm-season, frost-tender plants that need full sun and consistently warm soil to set fruit reliably, and picking the right variety and spacing matters as much as the planting date.

Choosing a Tomato Variety

Tomatoes fall into two growth habits, and picking the right one matters more than picking a specific cultivar.

Determinate (bush) varieties grow to a set height, ripen most of their fruit in one concentrated flush, and work well in containers or small beds. Roma and Celebrity are classic determinate choices, useful if you’re canning or freezing a big batch at once.

Indeterminate (vining) varieties keep growing and setting new fruit until frost kills the plant. Better Boy, Brandywine, Cherokee Purple, and Sun Gold cherry tomatoes are all indeterminate, and they need a sturdy cage or stake system to support the vine through the season.

If you’re short on space or want one big harvest for canning, choose determinate. If you want a steady supply of tomatoes from midsummer through fall, choose indeterminate and plan for taller support.

Spacing, Sun & Soil

Tomatoes need at least 6 to 8 hours of direct sun and consistently warm soil to grow well. Space determinate varieties 18 to 24 inches apart and indeterminate varieties 24 to 36 inches apart, with 3 to 4 feet between rows so plants get enough airflow to resist fungal disease.

Soil should be loamy, well-drained, and rich in organic matter, with a pH between 6.2 and 6.8. Work compost into the planting hole before transplanting, and wait until soil temperature reaches at least 60°F before setting plants outside. Cold soil stalls root growth even after the air has warmed up.

Watering

Tomatoes need about 1 to 1.5 inches of water per week, delivered deeply and infrequently rather than in frequent shallow sips. Deep watering encourages roots to grow downward instead of staying near the surface, which makes plants more drought-tolerant later in the season.

Water at the base of the plant instead of overhead. Wet foliage stays damp longer and invites fungal disease like early blight and septoria leaf spot. A soaker hose under a layer of mulch keeps soil moisture even, which also cuts down on blossom end rot.

Top Growing Tips

• Wait until soil reaches at least 60°F before transplanting; cold soil slows root development even once the air feels warm enough
• Plant deep: bury two-thirds of the stem (after removing the lower leaves) so roots form along the buried stem for a stronger plant
• Stake or cage indeterminate varieties early, before the plant sprawls, so you’re not fighting the vine later in the season
• Water consistently at the base of the plant; uneven watering is the top cause of blossom end rot and split fruit
• Mulch heavily with straw or shredded leaves to hold moisture, suppress weeds, and stop soil-borne fungal spores from splashing onto lower leaves
• Pinch off suckers on indeterminate varieties for fewer, larger fruit, or skip pinching if you’d rather have more, smaller tomatoes

Companion Planting

Good companions: basil, carrots, parsley, marigolds (a nematode deterrent), and alliums like onions and garlic.

Avoid planting near: brassicas (cabbage, broccoli, kale), fennel, corn (shares pest pressure with tomato fruitworm), and potatoes, since both are nightshades susceptible to the same blight and are best kept in separate beds.

Common Problems

Blossom end rot shows up as a sunken, leathery brown patch on the bottom of the fruit. It’s usually caused by inconsistent watering rather than a true calcium deficiency in the soil, so even, deep watering fixes it faster than adding calcium.

Tomato hornworms are large green caterpillars that strip leaves fast. Hand-pick them off in the early morning when they’re easiest to spot, or attract beneficial wasps that parasitize them.

Early blight and septoria leaf spot both cause yellowing, spotted lower leaves that spread upward. Remove affected leaves as soon as you see them, water at the base instead of overhead, and rotate where you plant tomatoes each year to keep spores from building up in the soil.

Cracking happens when a dry spell is followed by heavy rain or watering, causing fruit to swell faster than the skin can stretch. Consistent watering and mulch reduce the swings that cause it.

Harvest Timeline

Most varieties reach harvest 60 to 85 days after transplanting, though cherry tomatoes can ripen in as few as 55 days and large beefsteak types can take closer to 90.

Pick fruit when it’s fully colored but still slightly firm, and let the last green tomatoes of the season ripen indoors on a windowsill before the first fall frost. Once night temperatures drop into the 40s, ripening slows down a lot, so pulling in a late-season batch of green tomatoes is often worth it rather than leaving them on the vine.