Planting tomatoes at the right time is one of the most important factors when growing a successful crop. Plant tomatoes too soon and these tasty fruits can wither on the vine, but plant them too late and the foliage can wilt under the hot sun. Planting at the right time gives your tomatoes a strong start, ensuring healthy fruits and better crop yields. To ensure a prolific harvest, we spoke to garden experts to find out exactly when to plant tomatoes.

When to Plant Tomatoes

Tomatoes should be planted outdoors when nighttime temperatures are consistently above 50 degrees Fahrenheit and daytime temperatures remain above 60 degrees Fahrenheit. “Keep tomatoes in pots indoors under a plant light until outdoor temperatures reach this level,” says certified master gardener Mary Jane Duford. In most USDA Zones, this means late spring planting—often in April or May. “In hot climates with a long growing season, late summer planting can also work well for autumn harvest,” she adds.

What Happens if You Sow Tomatoes Too early?

Planting tomatoes too early can expose them to frost and heavy rains, which may cause them to die or grow slowly, says Adam Weiss, gardener and founder of Pike Lane Gardens. Additionally, tomato seeds sown too early outdoors may rot in the soil before they germinate, says Duford. Late spring cold and frost can damage roots and cause stunted, weak plants that never catch up.

What Happens if You Sow Tomatoes Too Late?

That said, planting too late isn’t good either. Tomatoes are a summer crop in many USDA zones, but if seeds are grown too late, there is a risk that temperatures will become too hot for the fragile leaves to handle, says Sara Rubens, certified garden coach and founder of Seed to Sanctuary.

What’s more, tomatoes need a long, warm season to grow and ripen fruit. “If you only have a few months before temperatures start to cool below about 50 degrees Fahrenheit on a regular basis, consider buying seedlings at the local plant nursery rather than sowing seeds,” says Duford.

Tips for Planting Tomatoes

Now that you know when to plant tomatoes, our experts say to keep these tips in mind when planting tomato seeds and seedlings.

Plant Seedlings Deep

If planting from seedlings, place your tomato seedlings deep into the soil. “The buried portion of the stem will develop additional roots, creating a stronger, more resilient plant with better access to nutrients and water,” says Weiss.

Transplant Seedlings on a Cloudy Morning

Young tomato plants are delicate. When transplanting seedlings, do so on a cloudy morning to protect the plants from direct hot sun. This will prevent transplant shock, helping the seedlings adjust smoothly to their new environment, says Weiss.

Add a Stake or Tomato Cage

Place a support, such as a cage, trellis, or stake, in the ground where you planted the tomato seedlings or seeds. This will ensure plants have the opportunity to vine upward, keeping any branches and leaves off the soil, says Rubens.

Remove the First Flowers

Pinching off the first round of buds will force more energy into the root system, encouraging more robust fruit production as the tomato plants begin to grow, says Rubens.

How to Care for Tomatoes After Planting

Don’t just plant your tomato seeds or seedlings and forget about them—these plants need regular attention to ensure they thrive.

Water Deeply

Water tomato plants deeply and regularly to carry essential nutrients and minerals to the roots, says Duford. Nutrient deficiency is common in tomatoes, even if the soil contains adequate nutrients, and is typically a consequence of not watering deeply enough.

Mulch Around Plants

Mulch the soil to keep the plant’s roots cool and moist. “While tomatoes like warm weather, they don’t grow particularly well in very hot weather,” Duford says. Mulch helps insulate the soil and keeps your tomatoes cool.

Use Supports

Use tomato cages or stakes to help the plants grow. Supports also ensure there is plenty of open space at the soil level to provide adequate airflow around the base of the plant to prevent disease, says Rubens.