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Sullivan County, NH — Planting Guide

Sullivan County is in USDA Zone 5b. The average last spring frost is May 12 and the first fall frost is October 7, giving you a growing season of approximately 148 days.

At an elevation of 495 ft, Sullivan County receives approximately 39.5 in of rainfall annually. Summer highs average 84°F with winter lows around 15°F. The predominant soil type is Silt Loam.

🌡️ Zone

5b (-15°F to -10°F min)

❄️ Last Frost

May 12

🍂 First Frost

October 7

📅 Growing Season

148 days

⛰️ Elevation

495 ft

🌧️ Annual Rainfall

39.5 in

Sullivan County, NH Short season
148 days
Last Spring Frost May 12
148 growing days
First Fall Frost October 7

Sullivan County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Zone 5b Frost Countdown
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Last Frost: May 12 First Frost: Oct 7

Soil & Growing Conditions in Sullivan County

Soil Type

Silt Loam

Ideal for most crops — holds moisture and nutrients while draining well.

Watering Needs

Moderate rainfall (39.5 in.) — plan to water 1–2 times per week during the growing season.

Season Tips

148-day frost-free season

Start warm-season crops indoors and focus on short-season varieties. Cold frames extend your season by 3–4 weeks in fall.

Your Free Printable Garden Planner

Plan every bed, every planting, every harvest — in one place. This 22-page printable includes your zone's planting calendar, a month-by-month task list, a seed inventory tracker, a harvest log, and succession-planting charts. Built to print, write in, and actually use all season.

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Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

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Digital pH Meter $10-20

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Organic Compost $8-30

Boost soil fertility and structure with rich, well-aged organic compost.

🥬 Vegetables to Grow in Sullivan County

105 vegetables that grow well in Zone 5b with planting dates for Sullivan County.

Show all 105 vegetables with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Acorn Squash Apr 7 May 19 May 26 Aug 18 – Sep 22 80–100
Amaranth Mar 17 May 19 May 26 Aug 25 – Oct 13 90–120
Arugula Apr 7 Apr 28 May 12 Jul 29 Jun 16 – Aug 18 30–50
Asparagus May 26 730–1095
Beets Apr 28 Jul 29 Jun 23 – Jul 21 50–70
Belgian Endive Apr 7 Apr 28 May 12 Jul 29 Sep 1 – Oct 27 110–150
Bitter Melon Mar 17 May 19 May 26 Jul 28 – Sep 8 60–90
Black Beans May 19 Aug 18 – Oct 6 90–120
Bok Choy Apr 7 Apr 28 May 12 Jul 29 Jun 23 – Jul 28 40–60
Broccoli Apr 7 Apr 28 May 12 Jul 29 Jul 14 – Aug 25 60–90
Broccoli Rabe Apr 7 Apr 28 May 12 Jul 29 Jun 23 – Jul 28 40–60
Brussels Sprouts Apr 7 Apr 28 May 12 Jul 29 Aug 11 – Oct 6 90–130
Butternut Squash Apr 7 May 19 May 26 Aug 25 – Sep 29 85–110
Cabbage Apr 7 Apr 28 May 12 Jul 29 Jul 14 – Sep 8 60–100
Calabash Mar 17 May 19 May 26 Aug 18 – Oct 13 80–120
Carrots Apr 28 Jul 29 Jun 30 – Aug 4 60–80
Cauliflower Apr 7 Apr 28 May 12 Jul 29 Jul 7 – Sep 8 55–100
Celeriac Apr 7 Apr 28 May 12 Jul 29 Aug 25 – Sep 29 100–120
Celery Apr 7 Apr 28 May 12 Jul 29 Aug 4 – Sep 29 80–120
Celtuce Apr 7 Apr 28 May 12 Jul 29 Jul 14 – Aug 25 60–90
Chard Apr 7 Apr 28 May 12 Jul 29 Jul 7 – Aug 25 50–60
Chickpeas Apr 7 Apr 28 May 12 Jul 29 Aug 4 – Sep 15 80–110
Chicory Apr 7 Apr 28 May 12 Jul 29 Jul 14 – Aug 25 60–85
Chinese Cabbage Apr 7 Apr 28 May 12 Jul 29 Jul 7 – Aug 4 50–70
Christmas Lima Beans Mar 17 May 19 May 26 Aug 18 – Sep 22 80–100
Collard Greens Apr 7 Apr 28 May 12 Jul 29 Jul 7 – Sep 8 55–75
Corn May 19 Jul 21 – Sep 15 60–100
Cowpeas May 19 Jul 21 – Sep 1 60–90
Cress Apr 7 Apr 28 May 12 Jul 29 May 26 – Jun 16 14–21
Crookneck Squash Apr 7 May 19 May 26 Jul 14 – Aug 11 45–60
Crosne Apr 28 Jul 29 Sep 29 – Oct 13 150–200
Cucumber Apr 7 May 19 May 26 Jul 21 – Sep 15 50–70
Daikon Apr 28 Jul 29 Jun 23 – Jul 21 50–70
Delicata Squash Apr 7 May 19 May 26 Aug 18 – Sep 22 80–100
Edamame May 19 Aug 4 – Sep 15 75–100
Eggplant Mar 3 May 19 May 26 Aug 4 – Oct 6 65–85
Endive Apr 7 Apr 28 May 12 Jul 29 Jun 30 – Aug 4 45–65
Escarole Apr 7 Apr 28 May 12 Jul 29 Jul 7 – Aug 4 50–70
Fava Beans Apr 7 Apr 28 May 12 Jul 29 Jul 28 – Sep 8 75–100
Fennel Mar 17 May 19 May 26 Jul 28 – Sep 8 60–90
Garlic Aug 26 Nov 25 – Feb 10 90–240
Green Beans May 19 Jul 14 – Sep 8 50–65
Horseradish May 26 Sep 29 – Nov 10 120–180
Hot Peppers Mar 3 May 19 May 26 Aug 4 – Nov 10 70–120
Hubbard Squash Apr 7 May 19 May 26 Sep 8 – Oct 13 100–120
Kabocha Apr 7 May 19 May 26 Aug 25 – Sep 22 85–100
Kai Lan Apr 7 Apr 28 May 12 Jul 29 Jun 30 – Jul 28 45–60
Kale Apr 7 Apr 28 May 12 Jul 29 Jul 7 – Sep 1 50–70
Kidney Beans May 19 Aug 18 – Sep 22 85–110
Kohlrabi Apr 7 Apr 28 May 12 Jul 29 Jun 30 – Aug 4 45–65
Komatsuna Apr 7 Apr 28 May 12 Jul 29 Jun 16 – Jul 21 35–50
Leeks Apr 7 Apr 28 May 12 Jul 29 Aug 11 – Oct 27 90–150
Lentils Apr 7 Apr 28 May 12 Jul 29 Aug 4 – Sep 15 80–110
Lettuce Apr 7 Apr 28 May 12 Jul 29 Jun 16 – Aug 25 30–60
Lima Beans May 19 Jul 21 – Sep 1 60–90
Mache Apr 7 Apr 28 May 12 Jul 29 Jun 23 – Jul 28 40–60
Melon Apr 7 May 19 May 26 Aug 4 – Sep 22 70–100
Microgreens Apr 7 Apr 28 May 12 Jul 29 May 19 – Jun 16 7–21
Mitsuba Apr 7 Apr 28 May 5 Jul 29 Jun 30 – Aug 25 50–70
Mizuna Apr 7 Apr 28 May 12 Jul 29 Jun 16 – Jul 14 30–45
Mustard Greens Apr 7 Apr 28 May 12 Jul 29 Jun 16 – Aug 18 30–50
Napa Cabbage Apr 7 Apr 28 May 12 Jul 29 Jul 7 – Aug 11 55–75
New Zealand Spinach Mar 17 May 19 May 26 Jul 21 – Aug 18 55–70
Okra Mar 17 May 19 May 26 Jul 21 – Sep 15 50–65
Onion Apr 7 Apr 28 May 12 Jul 29 Aug 11 – Sep 29 90–120
Pac Choi Apr 7 Apr 28 May 12 Jul 29 Jun 23 – Jul 21 40–55
Parsnip Apr 28 Jul 29 Aug 11 – Sep 22 100–130
Patty Pan Squash Apr 7 May 19 May 26 Jul 14 – Aug 11 45–60
Peas Apr 7 Apr 28 May 12 Jul 29 Jul 7 – Sep 1 55–70
Peppers Mar 3 May 19 May 26 Jul 28 – Oct 6 60–90
Pole Beans Mar 17 May 19 May 26 Jul 21 – Sep 15 55–70
Potatoes Mar 17 May 19 May 26 Aug 4 – Oct 13 70–120
Pumpkin Apr 7 May 19 May 26 Aug 25 – Oct 13 85–120
Purslane Apr 7 Apr 28 May 12 Jul 29 Jun 23 – Jul 28 40–60
Radicchio Apr 7 Apr 28 May 12 Jul 29 Jul 14 – Aug 18 60–80
Radish Apr 28 Jul 29 May 26 – Jun 16 22–35
Rhubarb Jun 2 365–730
Romanesco Apr 7 Apr 28 May 12 Jul 29 Jul 28 – Sep 8 75–100
Rutabaga Apr 28 Jul 29 Jul 21 – Aug 25 80–100
Salsify Apr 28 Jul 29 Aug 11 – Sep 22 100–130
Savoy Cabbage Apr 7 Apr 28 May 12 Jul 29 Jul 21 – Sep 15 70–110
Scallions Apr 7 Apr 28 May 12 Jul 29 Jul 7 – Aug 4 50–70
Scarlet Runner Beans Mar 17 May 19 May 26 Jul 28 – Sep 1 60–80
Shallot Apr 7 Apr 28 May 12 Jul 29 Aug 11 – Sep 29 90–120
Shiso Mar 24 May 19 May 26 Jul 21 – Sep 15 50–70
Snap Peas Mar 17 May 19 May 26 Jul 21 – Sep 15 55–70
Snow Peas Apr 7 Apr 28 May 12 Jul 29 Jul 7 – Sep 1 50–65
Soybeans May 19 Aug 11 – Oct 6 80–120
Spaghetti Squash Apr 7 May 19 May 26 Aug 25 – Sep 22 85–100
Spinach Apr 7 Apr 28 May 12 Jul 29 Jun 16 – Aug 18 35–50
Squash (Summer) Apr 7 May 19 May 26 Jul 14 – Sep 15 45–65
Squash (Winter) Apr 7 May 19 May 26 Aug 18 – Oct 13 80–120
Sunchoke May 26 Sep 15 – Nov 10 110–150
Sweet Corn May 19 Jul 21 – Sep 1 60–90
Sweet Potatoes Mar 17 May 19 May 26 Aug 25 – Oct 13 90–120
Tatsoi Apr 7 Apr 28 May 12 Jul 29 Jun 16 – Jul 21 35–50
Tomatillo Mar 17 May 19 May 26 Jul 28 – Oct 6 60–85
Tomatoes Mar 17 May 19 May 26 Jul 28 – Oct 6 60–85
Turnip Apr 28 Jul 29 Jun 9 – Jul 14 40–60
Watercress Apr 7 Apr 28 May 12 Jul 29 Jun 23 – Jul 28 40–60
Watermelon Apr 7 May 19 May 26 Aug 4 – Sep 22 70–100
Wax Beans May 19 Jul 14 – Sep 8 50–65
Winter Melon Mar 17 May 19 May 26 Aug 25 – Oct 13 90–120
Yard Long Beans Mar 17 May 19 May 26 Jul 21 – Sep 1 55–80
Zucchini Apr 7 May 19 May 26 Jul 14 – Sep 8 45–60

🍓 Fruits to Grow in Sullivan County

27 fruits that grow well in Zone 5b with planting dates for Sullivan County.

Show all 27 fruits with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Alpine Strawberries Jun 2 Sep 1 – Nov 17 90–180
Aronia Jun 2 730–1095
Blackberries Jun 2 365–730
Blueberries Jun 2 730–1095
Boysenberries Jun 2 365–730
Cantaloupe Jun 2 Aug 11 – Sep 15 70–90
Che Fruit Jun 2 1095–1825
Cranberries Jun 2 730–1095
Currants Jun 2 730–1095
Elderberries Jun 2 730–1095
Goji Berries Jun 2 730–1095
Gooseberries Jun 2 730–1095
Grapes Jun 2 730–1095
Ground Cherry Jun 2 Aug 11 – Oct 6 65–80
Hardy Kiwi Jun 2 1095–1825
Haskaps Jun 2 730–1095
Honeydew Jun 2 Aug 25 – Oct 6 80–110
Jostaberry Jun 2 730–1095
Lingonberries Jun 2 730–1095
Medlar Jun 2 1095–1825
Mulberries Jun 2 730–1825
Pawpaw Jun 2 1095–2555
Persimmon Jun 2 1095–2555
Quince Jun 2 1095–1825
Raspberries Jun 2 365–730
Serviceberries Jun 2 730–1095
Strawberries Jun 2 Sep 1 – Nov 17 90–365

🌿 Herbs to Grow in Sullivan County

34 herbs that grow well in Zone 5b with planting dates for Sullivan County.

Show all 34 herbs with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Angelica Apr 7 Apr 28 May 5 Jul 29 365–730
Anise Apr 7 Apr 28 May 5 Jul 29 Aug 4 – Oct 20 90–120
Basil Mar 24 May 19 May 26 Jul 21 – Sep 22 50–75
Bee Balm May 19 Aug 18 – Nov 3 90–120
Borage Apr 7 Apr 28 May 5 Jul 29 Jun 30 – Aug 18 50–60
Caraway Apr 7 Apr 28 May 5 Jul 29 365–450
Catnip May 19 Jul 21 – Sep 22 60–80
Chamomile Apr 7 Apr 28 May 5 Jul 29 Jul 7 – Sep 15 60–90
Chervil Apr 7 Apr 28 May 5 Jul 29 Jun 16 – Aug 18 40–60
Chives May 19 Jul 21 – Sep 29 60–90
Cilantro Apr 7 Apr 28 May 5 Jul 29 Jun 16 – Aug 18 40–60
Comfrey May 19 Jul 21 – Sep 29 60–90
Cumin Apr 7 Apr 28 May 5 Jul 29 Aug 18 – Oct 20 100–120
Dill Apr 7 Apr 28 May 5 Jul 29 Jun 16 – Aug 18 40–60
Epazote Mar 24 May 19 May 26 Jul 14 – Sep 8 45–60
Fennel (herb) Apr 7 Apr 28 May 5 Jul 29 Jul 7 – Sep 15 60–90
Feverfew May 19 Aug 18 – Nov 3 90–120
Garlic Chives May 19 Jul 21 – Sep 29 60–90
Horehound May 19 Aug 4 – Sep 29 75–90
Hyssop May 19 Jul 28 – Sep 29 70–90
Lemon Balm May 19 Jul 21 – Sep 8 60–70
Lemon Thyme May 19 Jul 28 – Sep 29 70–90
Lovage May 19 Jul 28 – Sep 29 70–90
Mint May 19 Jul 21 – Sep 29 60–90
Oregano May 19 Jul 21 – Sep 29 60–90
Parsley Apr 7 Apr 28 May 5 Jul 29 Jul 7 – Sep 8 60–80
Rue May 19 Jul 28 – Sep 29 70–90
Sage May 19 Aug 4 – Sep 29 75–90
Savory May 19 Jul 14 – Sep 8 50–70
Sorrel Apr 7 Apr 28 May 5 Jul 29 Jun 16 – Aug 18 40–60
Tarragon May 19 Jul 21 – Sep 29 60–90
Thai Basil Mar 24 May 19 May 26 Jul 21 – Sep 22 50–75
Thyme May 19 Jul 28 – Sep 29 70–90
Valerian May 19 Sep 22 – Nov 3 120–180

🌸 Flowers to Grow in Sullivan County

51 flowers that grow well in Zone 5b with planting dates for Sullivan County.

Show all 51 flowers with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Bloom Days to Maturity
Ageratum Mar 24 May 19 May 19 Jul 14 – Oct 13 60–75
Alliums Aug 26 Sep 30 – Oct 21 28–42
Anemones Apr 14 May 12 Jun 16 – Jul 14 90–120
Astilbe Mar 10 May 26 Aug 11 – Oct 20 70–100
Bachelor's Button Mar 31 Apr 21 May 12 Jul 14 – Sep 29 60–90
Begonias Mar 3 May 19 Jul 28 – Oct 20 70–90
Black-eyed Susan Mar 10 May 12 May 26 Aug 11 – Nov 17 60–80
Bleeding Hearts Mar 10 May 26 Jul 21 – Sep 1 60–90
Calendula Mar 31 Apr 21 May 12 Jun 30 – Sep 29 50–70
Celosia Apr 7 May 19 May 19 Jul 21 – Oct 27 60–90
Columbine Mar 10 May 26 May 26 Jul 21 – Sep 1 70–100
Coreopsis Mar 10 May 19 May 26 Aug 4 – Nov 17 60–80
Cosmos Apr 14 May 12 May 12 Jul 21 – Oct 20 60–90
Crocus Aug 26 Jul 8 – Jul 29 10–20
Daffodils Aug 26 Jul 15 – Aug 5 20–40
Dahlias Apr 14 May 19 May 19 Aug 11 – Nov 10 70–120
Daylily Mar 10 May 26 Aug 18 – Nov 17 60–90
Dianthus Mar 10 Apr 14 Apr 28 Jun 16 – Sep 8 60–80
Echinacea (Purple Coneflower) Mar 10 May 26 May 26 Aug 18 – Nov 17 70–90
Foxglove Mar 10 May 26 May 26 Jul 21 – Sep 1 80–120
Gaillardia (Blanket Flower) Mar 17 May 19 May 19 Jul 28 – Nov 17 70–100
Geraniums Mar 3 May 19 Jul 28 – Oct 20 70–100
Gladiolus May 19 May 19 Aug 11 – Nov 10 70–100
Hostas Mar 3 May 26 Aug 18 – Nov 17 60–90
Hyacinths Aug 26 Aug 5 – Sep 2 14–28
Hydrangeas Mar 3 May 26 Aug 11 – Nov 3 90–150
Impatiens Mar 17 May 19 Jul 28 – Oct 27 60–75
Irises Division May 26 Jul 21 – Aug 25 60–100
Larkspur Apr 14 Jun 23 – Aug 18 60–90
Lavender Mar 3 Jun 2 Aug 11 – Sep 29 90–120
Lilies Division May 26 Aug 4 – Nov 3 70–120
Lobelia Mar 3 May 5 Jun 30 – Sep 15 70–80
Lupine Mar 10 May 26 May 26 Jul 21 – Sep 1 75–100
Marigolds Mar 31 May 19 May 19 Jul 14 – Oct 13 50–70
Nasturtium Apr 14 May 19 May 19 Jul 14 – Oct 27 55–65
Pansy Mar 3 May 12 Jul 7 – Sep 8 70–90
Peonies Division May 26 Aug 4 – Sep 15 90–120
Petunia Mar 17 May 19 Jul 28 – Oct 27 70–90
Phlox Mar 10 May 26 May 26 Aug 11 – Nov 3 80–110
Portulaca Apr 7 May 19 May 19 Jul 7 – Oct 13 50–70
Roses Mar 3 May 26 Aug 11 – Nov 17 90–180
Salvia Mar 10 May 19 Jul 28 – Oct 27 70–90
Sedum (Stonecrop) Mar 10 May 26 Sep 22 – Dec 1 60–90
Snapdragon Mar 3 Apr 28 May 12 Jul 21 – Sep 29 70–100
Sunflower Apr 21 May 19 May 19 Aug 11 – Oct 27 70–100
Sweet Alyssum Mar 24 Apr 28 May 12 Jun 23 – Sep 1 45–60
Sweet Pea Mar 31 Apr 7 May 12 Jul 28 – Sep 29 65–85
Tulips Aug 26 Jul 29 – Aug 19 15–30
Vinca (Annual) Feb 24 May 19 Jul 28 – Oct 20 70–90
Yarrow Mar 10 May 12 May 26 Aug 4 – Nov 17 60–90
Zinnia Apr 14 May 19 May 19 Jul 28 – Oct 27 60–70

Monthly Planting Guide for Sullivan County

Gardening Guides & Resources

Helpful guides from The Ultimate Homestead to improve your garden in Sullivan County.

Frequently Asked Questions

What planting zone is Sullivan County, NH?

Sullivan County is in USDA Hardiness Zone 5b. This zone classification determines which perennial plants survive winter and sets the baseline for frost timing across the county.

When is the last frost in Sullivan County, NH?

Based on 30 years of NOAA weather station data, the median last spring frost in Sullivan County falls around May 12. Plan transplants and direct-sow dates relative to this date.

When is the first fall frost in Sullivan County, NH?

The median first fall frost in Sullivan County arrives around October 7. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.

🌱

Your Sullivan County Garden Planner — Free

A 22-page printable planner built for Sullivan County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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The pairings that make vegetables, herbs, and flowers grow better — and the ones that quietly wreck a bed.

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Composting Guide for Homesteaders

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Turn kitchen scraps and yard waste into compost that actually feeds the garden — instead of a pile that smells, attracts pests, and never breaks down.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates represent 50% probability averages; local conditions vary by elevation and microclimate. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.