February 28, 2026

When to Plant Tomatoes in Zone 6

Zone 6 sits in a sweet spot for tomato growing. You've got a solid 170-180 frost-free days in most locations, which means nearly every tomato variety is on the table — including the big, slow heirlooms that zone 5 gardeners can only dream about.

That said, zone 6 still gets frost. Late April freezes happen. And every year, someone on a gardening forum posts about losing all their transplants to a May cold snap because they jumped the gun. Don't be that person.

Your planting timeline

The standard advice — transplant two weeks after your last frost — works well here. But pay attention to soil temperature too. Grab a cheap soil thermometer and wait until the ground hits 60°F at 4 inches deep. In zone 6, that usually lines up with mid to late April in 6b and early May in 6a.

Seed starting details

Six to eight weeks before transplant puts most zone 6 gardeners starting seeds between mid-February and early March. That's still deep winter in much of zone 6, so you'll need supplemental light — even a south-facing window isn't enough in February.

Here's what works:

• Use a seed starting mix, not garden soil. Garden soil compacts in containers and brings along fungal problems.
• Bottom heat speeds germination from 10 days down to 5-7. A basic heat mat costs about $20.
• Once seedlings emerge, drop the temperature to 65-70°F daytime. This prevents leggy growth.
• Pot up to 4" containers when the first true leaves appear. Burying the stem slightly encourages root growth along the buried portion.

Choosing varieties

Zone 6 gardeners have it good. Your season is long enough for virtually any variety, but choosing a mix of early and mid-season types spreads your harvest across more weeks. For more details, see our guide on When to plant tomatoes by zone.

Transplanting tips

When you move seedlings outside, bury them deep — up to the top set of leaves. Tomatoes root along their buried stems, which makes for stronger, more drought-resistant plants. This works for tomatoes (and only tomatoes — don't try it with peppers). For more details, see our guide on When to Plant Tomatoes in Zone 5.

Space plants 24-36 inches apart for indeterminate types, 18-24 inches for determinates. Set up your support system (cages, stakes, or the Florida weave) at transplant time, not later when you'll disturb roots.

Water deeply at transplant. A diluted fish emulsion feed helps reduce transplant shock, but it's not mandatory. Skip fertilizer for the first two weeks after planting — let the roots establish first.

Dealing with late frosts

Zone 6 is notorious for "one more frost" after you think spring has arrived. Keep row cover or old bed sheets handy through mid-May. If overnight temps drop below 38°F, cover your plants. It takes five minutes and can save your entire crop.

Wall o' Water cloches let aggressive gardeners transplant 2-3 weeks earlier than the standard timeline. They're worth it if you're in 6a and want tomatoes by late June.

Season extension

On the back end of the season, zone 6 gardeners can stretch harvests into November with some simple protection:

• Cover plants with row cover when overnight temps start hitting the 30s (usually October).
• Pick tomatoes at the "breaker" stage — when they first show a blush of color — and ripen indoors. They taste nearly as good as vine-ripened.
• Determinate varieties that ripen all at once are easier to protect than sprawling indeterminates with fruit at every stage.

Zone 6 gives you a great balance: warm enough for a long harvest, but with real seasons that keep things interesting. Plug your zip code into the planting calendar for dates customized to your exact location, and check out the full zone-by-zone tomato guide for comparisons.