When To Plant Tomatoes In Vermont

If you’re planning your Vermont garden, knowing when to plant tomatoes is your first step to a great harvest. Getting the timing right for when to plant tomatoes in Vermont makes all the difference between a thriving crop and a disappointing one. Our short springs and cool nights mean we can’t rush the season. This guide will walk you through the best dates, varieties, and techniques for success in our unique climate.

For most of Vermont, the safe window for planting tomatoes outdoors falls between Memorial Day and mid-June. The classic rule is to wait until after the last average frost date. Relying on a calendar date alone is risky, though. You must also watch the weather and soil conditions each year.

Understanding Vermont’s Last Frost Dates

Our state has a range of microclimates. The last spring frost can vary by several weeks from one town to the next.

Southern Vermont (e.g., Brattleboro, Bennington): Last frost around May 15-25.
Central Vermont (e.g., Montpelier, Rutland): Last frost around May 25 – June 5.
Northern Vermont & Champlain Valley (e.g., Burlington, St. Albans): Last frost around May 25 – June 5. Lake Champlain can moderate temps.
Northeast Kingdom & Higher Elevations: Last frost can be as late as June 10-15. Always err on the side of caution here.

These are averages. Always check a local forecast for your exact area before you plant anything outside.

Why You Can’t Plant Tomatoes Too Early

Tomatoes are tropical plants. They hate cold soil and cold air. Planting too early stunts there growth and makes them vulnerable to disease. Here’s what happens:

Soil Temperature: Tomato roots need soil consistently above 60°F. Cold soil shocks them and prevents nutrient uptake.
Air Temperature: Temperatures below 50°F can cause chilling injury. Frost (32°F) will kill them outright.
Stunted Growth: The plant will just sit there, not growing, while it waits for warmth. You won’t get ahead.

The 7-Day Weather Check Before Planting

Once your calendar date is near, do this final check:

Check the 10-day forecast. Ensure nighttime temps will stay above 45°F.
Feel the soil. It should be warm and dry to the touch, not cold and soggy.
Look for a favorable forecast. A stretch of sunny, mild days after planting helps roots establish.

Starting Seeds Indoors: Your Head Start

Since our outdoor season is short, we start seeds inside. This gives plants a 6-8 week jump on the growing season.

When to Start: Sow tomato seeds indoors 6-8 weeks before your last frost date. For a May 30 frost date, start seeds around April 1-15.
Key Tips: Use a seed-starting mix, provide strong light (a sunny window often isn’t enough), and keep them warm.
Hardening Off: This is non-negotiable. For 7-10 days before transplanting, gradually expose seedlings to outdoor conditions for a few more hours each day.

Choosing the Best Tomato Varieties for Vermont

Selecting varieties bred for cooler climates and shorter seasons is a smart move. Look for terms like “early season,” “cold-tolerant,” or “short season” (under 70 days to maturity).

Recommended Early-Season Varieties

Cherry Tomatoes: ‘Sungold’, ‘Black Cherry’, ‘Early Cascade’. These are often the first to ripen.
Slicing Tomatoes: ‘Early Girl’, ‘Stupice’, ‘Glacier’, ‘Moskvich’. They produce reliable fruit even in cooler summers.
Paste Tomatoes: ‘Juliet’, ‘Granadero’. Good for sauces and canning.

Consider Disease Resistance

Our humid summers can bring disease. Look for letters on plant tags like V (verticillium wilt), F (fusarium wilt), and LB (late blight). Varieties like ‘Mountain Merit’ or ‘Defiant’ offer strong resistance.

Step-by-Step Guide to Planting Day

Prepare the Soil: Pick a full-sun spot (8+ hours). Work in plenty of compost. Soil should be well-draining.
Dig Deep or Trench: Tomatoes root along their stems. Bury the stem up to the first set of true leaves. You can plant deep or lay the rootball sideways in a trench.
Add Amendments: Put a handful of organic fertilizer or a crushed eggshell (for calcium) in the planting hole. Mix it with soil so roots aren’t directly touching it.
Plant & Water: Set the plant in, fill with soil, and water deeply to settle the roots. This eliminates air pockets.
Add Support: Install cages or stakes right away to avoid damaging roots later.

Protecting Your Young Tomato Plants

Vermont weather is unpredictable. Have these protections ready for unexpected cold snaps.

Cloches: Use wall-o-water devices, milk jugs with bottoms cut off, or commercial cloches. They trap heat.
Row Cover: Lightweight fabric (frost blanket) draped over plants can provide a few degrees of protection.
Mulch, But Later: Wait until the soil is truly warm (late June) before applying mulch. Black plastic mulch can help warm soil earlier.

What If You Planted Too Early?

If a surprise frost is forecast after you’ve planted, don’t panic. Cover the plants immediately with blankets, buckets, or row cover. Uncover them in the morning once the temperature rises. If plants look damaged, wait a few days; they may recover from the roots or undamaged parts of the stem.

FAQs: Planting Tomatoes in Vermont

Q: Can I plant tomatoes in Vermont in May?
A: In southern Vermont, late May might be safe if the weather is warm. In central and northern Vermont, early May is usually to early. Always check soil temp and the frost forecast.

Q: What is the best month to plant tomatoes in VT?
A: June is the safest bet for most of the state. Early June for warmer areas, mid-June for cooler and higher elevation areas.

Q: How do I get my tomatoes to ripen before frost in Vermont?
A: Choose early varieties, prune suckers to focus energy, and pinch off new blossoms in late August so the plant puts energy into existing fruit. If frost threatens, you can pick mature green tomatoes and ripen them indoors.

Q: Should I use determinate or indeterminate tomatoes in Vermont?
A> Both can work. Determinate (bush) types set fruit all at once, good for canning and shorter seasons. Indeterminate (vining) types produce until frost but need more care and a longer season; choose early indeterminates.

Q: Can I plant store-bought seedlings directly outside?
A> Not immediately. They need to be hardened off first, just like home-started seedlings. Store-bought plants are often grown in ideal greenhouse conditions and will suffer if put straight into the garden.

Patience is the hardest part of Vermont gardening. Waiting for the right moment to plant tomatoes in Vermont pays off with stronger, more productive plants. By following the local frost dates, choosing resilient varieties, and being prepared to protect your young plants, you’ll set the stage for a summer full of fresh, homegrown tomatoes. Keep a eye on the weather, trust the process, and your garden will thank you.