When Is It Safe to Plant Tomatoes on Long Island?

Herbs and Vegetables

Tomatoes are one of the most popular vegetables grown in Long Island gardens, and for good reason. Nothing compares to the flavor of a fresh, homegrown tomato picked right off the vine in the middle of summer. But timing is everything when it comes to planting tomatoes outdoors. Plant too early, and cold temperatures can damage or stunt your plants before the growing season even begins.

So, when is it safe to plant tomatoes on Long Island?

The garden bed thrives with tomato plants, neatly supported by wooden stakes. Amidst the lush green foliage, ripe red tomatoes mingle with their green counterparts, showcasing a well-maintained oasis of growth and color.

Stake tomato plants early to support healthy growth and keep fruit off the ground.

Planting Tomatoes in the Garden

Plant tomatoes deep to encourage stronger roots and healthier growth.

Wait Until the Danger of Frost Has Passed

In most parts of Long Island, the safest time to plant tomatoes outdoors is between mid-May and late May. Many local gardeners use Mother’s Day as a general guideline for when it is finally warm enough to transplant tomato seedlings into the garden.

Tomatoes are warm-weather plants that do not tolerate frost or cold soil. Even if the days feel warm in April or early May, nighttime temperatures can still dip into the 40s across Long Island. These chilly conditions can stress young tomato plants and slow their growth. For healthy plants, nighttime temperatures should consistently stay above 50°F, while soil temperatures should be at least 60°F before planting.

Assorted Heirloom Tomatoes

Heirloom Tomato

Plum Tomatoes

Plum Tomato

Why Long Island Weather Can Be Tricky

Long Island’s coastal climate helps moderate temperatures, but spring weather can still be unpredictable. Nassau County often warms up slightly earlier than eastern Suffolk County, while areas closer to the water may stay cooler at night longer into the season. Late spring cold snaps are not uncommon, which is why planting tomatoes too early can be risky. Cold-stressed plants may develop yellow leaves, stop growing, or struggle to produce fruit later in the season. The good news is that tomatoes planted at the proper time often catch up quickly and outperform plants that were set out too early.

A close-up of a ripe, vibrant red heirloom tomato hanging from a green vine showcases deep grooves and a plump shape. Tomato leaves surround it, lush and green, hinting at the presence of another orange tomato nearby.

Brandywine Tomato

A ripe, red tomato gleams with water droplets as it sits elegantly on a bed of crisp, fresh green lettuce leaves.

Beefsteak Tomato

Tips for Planting Tomatoes Successfully: Harden Off Plants Before Planting

If you started tomatoes indoors or purchased seedlings from a garden center, it is important to “harden off” the plants before placing them in the garden full time. This means gradually exposing them to outdoor conditions over the course of about a week. Start by placing plants outside for a few hours each day in a sheltered location, slowly increasing their time outdoors. This process helps prevent transplant shock.

Rows of young tomato plants in black plastic pots sit on a wooden porch, next to the side of a house, with a green yard and trees visible in the background.

Harden off tomato plants prior to planting.

Row of garden plants covered with white garden fabric, held down by rocks, protecting the plants from cold or pests; wooden stakes and a garden area are visible in the background.

Frost cloth protecting tomatoes during cold temperatures.

Pick a Sunny Location

Tomatoes thrive in full sun and need at least 6 to 8 hours of direct sunlight daily. Choose a spot with:

  • Well-draining soil
  • Good airflow
  • Plenty of sunlight throughout the day

Adding compost or organic matter to the soil before planting can also improve growth and fruit production.

Protect Plants During Cool Nights

Even after planting season begins, it is smart to keep an eye on the forecast. If temperatures unexpectedly drop, cover young tomato plants overnight with:

  • Frost cloth
  • Lightweight blankets
  • Buckets or garden covers

This extra protection can help prevent damage during sudden cold snaps.

    Cluster of ripe, red Roma tomatoes hanging on the vine with green leaves in the background.

    Roma Tomato

    Clusters of ripe yellow cherry tomatoes hanging on a vine among green leaves in a garden.

    Sungold Cherry Tomato

    A cluster of four ripe, red tomatoes growing on a vine, surrounded by green leaves in a garden.

    Early Girl Tomato

    Best Tomato Varieties for Long Island Gardens

    Long Island gardeners have success with many tomato varieties, including:

    • Beefsteak
    • Roma
    • Better Boy
    • Early Girl
    • Sungold cherry tomatoes

    Cherry tomatoes are especially popular because they grow quickly and produce heavily throughout the summer.

    A close-up of a BLT sandwich on toasted bread, layered with crispy bacon, fresh lettuce, sliced tomatoes, and mayonnaise, served on a white plate with tomatoes and lettuce in the background.
    A fresh salad with lettuce, sliced cucumbers, cherry tomatoes, red onion, yellow tomatoes, and crumbled feta cheese, seasoned with black pepper, served in a white bowl.

    Enjoy Fresh Tomatoes All Summer

    Waiting until mid-to-late May to plant tomatoes gives your garden the best chance for success. Warm soil, mild nights, and plenty of sunshine help tomato plants grow strong and produce an abundant summer harvest.

    With proper timing and care, you’ll be enjoying fresh Long Island tomatoes straight from your backyard all season long.

    Additional Information:

    How to Start a Vegetable Garden

    SHOP Supplies