When to Plant in Connecticut: Vegetable & Flower Planting Calendar
Quick answer
Plant around your local last spring frost: across the 289 Connecticut ZIP codes where frost comes in most years, the median is Apr 20 and the median first fall frost is Oct 20 (nearest NOAA station, 1991–2020). Transplant tomatoes 1–2 weeks after your last frost: Zone 6 areas: May 2 – May 9; Zone 7 areas: Apr 23 – Apr 30.
Connecticut spans USDA hardiness zones 6a–7b on the 2023 USDA map (by ZIP code, via PRISM). For the 289 of its 289 ZIP codes where frost comes in most years, the nearest NOAA station’s median last spring frost (32°F, 1991–2020) is Apr 20 (middle 80% of ZIP codes: Apr 12 – May 3) and the median first fall frost is Oct 20 (Oct 11 – Oct 31). Use this guide to time seed-starting, transplanting and fall planting.
Where these dates come from: every date range is counted from the median (50% probability) 32°F last spring and first fall frost dates in NOAA’s 1991–2020 U.S. Climate Normals for the area shown. The rule under each date, such as “4–6 weeks before last frost,” shows how it was counted. These are averages: in about half of years a frost still comes after the spring date, and elevation, nearby water and microclimate can shift your yard by a week or more. For dates for your exact location, enter your ZIP code in the planner.
How we count planting dates: the weeks before or after frost for each crop come from university extension planting guides: UNH Extension, When to Plant Your Vegetable Garden; Rutgers FS787, Starting Vegetable Seeds Indoors; Virginia Tech 426-331, Home Garden Vegetable Planting Guide; University of Maryland Extension, Vegetable Planting Calendar; and University of Idaho CIS 1209 (marigolds and zinnias). Bulb windows approximate Rutgers’ rule to plant when soil falls below 60°F (FS1220), and garlic follows SDSU, Illinois and Virginia Tech. Temperature notes: UMD (potatoes), UMN (sweet corn), UC ANR (peppers, hardening off), UMN (eggplant), Colorado State (tomatoes) and SDSU (hardening off).
Connecticut frost dates by zone area
| Zone areas | Most common nearest NOAA stations | Median last spring frost (32°F) | Median first fall frost (32°F) |
|---|---|---|---|
| Zone 6 (219 ZIP codes) | Hartford Brainard Fld, CT, Meriden Markham Muni Airport, CT, Norwich Public Utility Plt, CT | Apr 25middle 80%: Apr 17 – May 7 | Oct 17middle 80%: Oct 9 – Oct 26 |
| Zone 7 (68 ZIP codes) | Stamford 5 N, CT, Bridgeport Sikorsky Mem Airport, CT, New Haven Tweed Airport, CT | Apr 16middle 80%: Apr 5 – Apr 17 | Oct 28middle 80%: Oct 23 – Nov 6 |
Source: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991–2020, annual/seasonal freeze-date probabilities (32°F, 50% probability). Station-level medians; your yard may differ.
How this table is built: each Connecticut ZIP code is matched to its nearest NOAA 1991–2020 freeze-data station (within 60 miles) and grouped by its 2023 USDA hardiness zone; dates are medians across the ZIP codes in each group. Some nearest stations are across the state line (Carmel 4N, NY, Millbrook 3 W, NY, N Foster 1 E, RI, Orient Pt Sp, NY, Southbridge 3 Sw, MA, Westchester Co Airport, NY…). For your own ZIP, use the planner.
Connecticut vegetable planting calendar
Planting dates for each zone area of Connecticut, counted from that area’s median frost dates (shown under each column). Rows run in calendar order. For your exact dates, enter your ZIP.
| Plant, task and rule | Zone 6 areasLast frost Apr 25 · First frost Oct 17 | Zone 7 areasLast frost Apr 16 · First frost Oct 28 |
|---|---|---|
| Broccoli · Start indoors8–10 weeks before last frost | Feb 14 – Feb 28 | Feb 5 – Feb 19 |
| Cabbage · Start indoors8–10 weeks before last frost | Feb 14 – Feb 28 | Feb 5 – Feb 19 |
| Kale · Start indoors8–10 weeks before last frost | Feb 14 – Feb 28 | Feb 5 – Feb 19 |
| Tomatoes · Start indoors6–8 weeks before last frost | Feb 28 – Mar 14 | Feb 19 – Mar 5 |
| Peppers · Start indoors6–8 weeks before last frost | Feb 28 – Mar 14 | Feb 19 – Mar 5 |
| Eggplant · Start indoors6–8 weeks before last frost | Feb 28 – Mar 14 | Feb 19 – Mar 5 |
| Peas · Direct sow4–6 weeks before last frost | Mar 14 – Mar 28Harvest (est.) May 13 – Jun 16 | Mar 5 – Mar 19Harvest (est.) May 4 – Jun 7 |
| Spinach · Direct sow4–6 weeks before last frost | Mar 14 – Mar 28Harvest (est.) Apr 28 – May 27 | Mar 5 – Mar 19Harvest (est.) Apr 19 – May 18 |
| Basil · Start indoors4–6 weeks before last frost | Mar 14 – Mar 28 | Mar 5 – Mar 19 |
| Radishes · Direct sow2–5 weeks before last frost | Mar 21 – Apr 11Harvest (est.) Apr 10 – May 11 | Mar 12 – Apr 2Harvest (est.) Apr 1 – May 2 |
| Lettuce · Direct sow2–4 weeks before last frost | Mar 28 – Apr 11Harvest (est.) May 27 – Jun 30 | Mar 19 – Apr 2Harvest (est.) May 18 – Jun 21 |
| Onions (sets/transplants) · Plant sets/transplants2–4 weeks before last frost | Mar 28 – Apr 11Harvest (est.) Jun 21 – Aug 9 | Mar 19 – Apr 2Harvest (est.) Jun 12 – Jul 31 |
| Broccoli · Transplant2–4 weeks before last frost | Mar 28 – Apr 11Harvest (est.) May 17 – Jun 20 | Mar 19 – Apr 2Harvest (est.) May 8 – Jun 11 |
| Cabbage · Transplant2–4 weeks before last frost | Mar 28 – Apr 11Harvest (est.) Jun 6 – Jul 10 | Mar 19 – Apr 2Harvest (est.) May 28 – Jul 1 |
| Kale · Transplant2–4 weeks before last frost | Mar 28 – Apr 11 | Mar 19 – Apr 2 |
| Marigolds · Start indoors0–3 weeks before last frost (3–4 weeks before setting out; Univ. of Idaho) | Apr 4 – Apr 25 | Mar 26 – Apr 16 |
| Zinnias · Start indoors0–3 weeks before last frost (3–4 weeks before setting out; Univ. of Idaho) | Apr 4 – Apr 25 | Mar 26 – Apr 16 |
| Potatoes · Plant seed potatoes1–2 weeks before last frost | Apr 11 – Apr 18Harvest (est.) Jul 5 – Aug 6 | Apr 2 – Apr 9Harvest (est.) Jun 26 – Jul 28 |
| Marigolds · Direct sow / transplantfrom the last frost to 2 weeks after (Univ. of Idaho) | Apr 25 – May 9 | Apr 16 – Apr 30 |
| Zinnias · Direct sow / transplantfrom the last frost to 2 weeks after (Univ. of Idaho) | Apr 25 – May 9 | Apr 16 – Apr 30 |
| Tomatoes · Transplant1–2 weeks after last frost | May 2 – May 9Harvest (est.) Jul 11 – Aug 7 | Apr 23 – Apr 30Harvest (est.) Jul 2 – Jul 29 |
| Beans (bush & pole) · Direct sow1–2 weeks after last frost | May 2 – May 9Harvest (est.) Jun 16 – Jul 18 | Apr 23 – Apr 30Harvest (est.) Jun 7 – Jul 9 |
| Sweet corn · Direct sow1–2 weeks after last frost | May 2 – May 9Harvest (est.) Jul 6 – Aug 7 | Apr 23 – Apr 30Harvest (est.) Jun 27 – Jul 29 |
| Cucumbers · Direct sow1–2 weeks after last frost | May 2 – May 9Harvest (est.) Jun 11 – Jul 13 | Apr 23 – Apr 30Harvest (est.) Jun 2 – Jul 4 |
| Squash · Direct sow1–2 weeks after last frost | May 2 – May 9Harvest (est.) Jun 11 – Jun 28 | Apr 23 – Apr 30Harvest (est.) Jun 2 – Jun 19 |
| Pumpkins · Direct sow1–3 weeks after last frost | May 2 – May 16Harvest (est.) Jul 21 – Aug 24 | Apr 23 – May 7Harvest (est.) Jul 12 – Aug 15 |
| Basil · Transplant1–2 weeks after last frost | May 2 – May 9Harvest (est.) Jun 13 – Jun 20 | Apr 23 – Apr 30Harvest (est.) Jun 4 – Jun 11 |
| Peppers · Transplant2–3 weeks after last frost | May 9 – May 16Harvest (est.) Jul 13 – Jul 30 | Apr 30 – May 7Harvest (est.) Jul 4 – Jul 21 |
| Eggplant · Transplant2–3 weeks after last frost | May 9 – May 16Harvest (est.) Jul 18 – Aug 14 | Apr 30 – May 7Harvest (est.) Jul 9 – Aug 5 |
| Broccoli · Fall transplant10–12 weeks before first fall frost | Jul 25 – Aug 8Harvest (est.) Sep 13 – Oct 17 | Aug 5 – Aug 19Harvest (est.) Sep 24 – Oct 28 |
| Cabbage · Fall transplant10–12 weeks before first fall frost | Jul 25 – Aug 8Harvest (est.) Oct 3 – Nov 6 | Aug 5 – Aug 19Harvest (est.) Oct 14 – Nov 17 |
| Kale · Fall sow8–10 weeks before first fall frost | Aug 8 – Aug 22Harvest (est.) Sep 27 – Oct 31 | Aug 19 – Sep 2Harvest (est.) Oct 8 – Nov 11 |
| Lettuce · Fall sow6–8 weeks before first fall frost | Aug 22 – Sep 5Harvest (est.) Oct 21 – Nov 24 | Sep 2 – Sep 16Harvest (est.) Nov 1 – Dec 5 |
| Spinach · Fall sow4–7 weeks before first fall frost (Virginia Tech) | Aug 29 – Sep 19Harvest (est.) Oct 13 – Nov 18 | Sep 9 – Sep 30Harvest (est.) Oct 24 – Nov 29 |
| Radishes · Fall sow4–6 weeks before first fall frost | Sep 5 – Sep 19Harvest (est.) Sep 25 – Oct 19 | Sep 16 – Sep 30Harvest (est.) Oct 6 – Oct 30 |
| Daffodils · Fall plant bulbs4 weeks before to 2 weeks after first fall frost (our approximation of when soil falls below 60°F; Rutgers) | Sep 19 – Oct 31 | Sep 30 – Nov 11 |
| Tulips · Fall plant bulbs2 weeks before to 4 weeks after first fall frost (our approximation of when soil falls below 60°F; Rutgers) | Oct 3 – Nov 14 | Oct 14 – Nov 25 |
| Garlic · Fall plant cloves2 weeks before to 3 weeks after first fall frost, while the soil is still workable (SDSU, Illinois, Virginia Tech) | Oct 3 – Nov 7Harvest (est.) Jun 10, 2027 – Aug 4, 2027 | Oct 14 – Nov 18Harvest (est.) Jun 21, 2027 – Aug 15, 2027 |
About the harvest estimates
Each expected harvest window adds the days to harvest from the sources below to the planting window. Days count from sowing seed (or planting seed potatoes, onion sets or garlic cloves) or, where marked, from setting transplants out; “Start indoors” rows have no harvest of their own. Harvest timing varies with variety and weather, and many crops keep producing for weeks after the first picking. For frost-tender crops (tomatoes, peppers, eggplant, beans, sweet corn, cucumbers, squash, pumpkins, basil) the window stops at the first fall frost: harvest may end early at the first fall frost. Flowers and bulbs show no harvest window, and kale has no sourced figure for spring transplants.
Sources: UF/IFAS Extension, Florida Vegetable Gardening Guide (SP103/VH021), Table 1, “Days to Harvest”; University of Maryland Extension, Growing Onions in a Home Garden; University of Maryland Extension, Growing Garlic in a Home Garden; University of Maryland Extension, Growing Basil in a Home Garden.
Growing notes for each crop
- Peas: Tolerates light frost; sow when soil is workable
- Spinach: Fall crop too: sow 4–7 weeks before first fall frost (Virginia Tech)
- Lettuce: Bolts in heat; succession sow; fall crop too
- Radishes: Fast (3–4 weeks); sow again for fall (see Fall sow dates)
- Kale: Fall crop too (see Fall sow dates); frost sweetens leaves
- Onions (sets/transplants): Choose day-length type suited to your latitude
- Potatoes: Soil at least 45°F (UMD); hill as plants grow
- Broccoli: Cool-season; harden off; good fall crop
- Cabbage: Cool-season; harden off; good fall crop
- Tomatoes: Wait for nights reliably above about 52°F (Colorado State)
- Peppers: Need warm soil: about 65°F is optimal for transplanting (UC ANR)
- Eggplant: Transplant after nights stay above 50°F (UMN)
- Beans (bush & pole): Seeds rot in cold, wet soil
- Sweet corn: Soil 60°F+ (UNH, UMN); plant in blocks for pollination
- Cucumbers: Frost-tender; watch for cucumber beetles
- Squash: Frost-tender; watch for squash vine borer
- Pumpkins: For October pumpkins, many sow in late May–June
- Basil: Very cold-sensitive
- Marigolds: Easy warm-season annual
- Zinnias: Easy warm-season annual
- Tulips: Our frost-date window is an approximation of that soil rule. In zone 9, chill bulbs 12–16 weeks first (Clemson)
- Daffodils: Our frost-date window is an approximation of that soil rule; slightly earlier than tulips is fine
- Garlic: Harvest the following early summer
Connecticut USDA zone guides: Zone 6 planting guide Zone 7 planting guide
How we count planting dates: the weeks before or after frost for each crop come from university extension planting guides: UNH Extension, When to Plant Your Vegetable Garden; Rutgers FS787, Starting Vegetable Seeds Indoors; Virginia Tech 426-331, Home Garden Vegetable Planting Guide; University of Maryland Extension, Vegetable Planting Calendar; and University of Idaho CIS 1209 (marigolds and zinnias). Bulb windows approximate Rutgers’ rule to plant when soil falls below 60°F (FS1220), and garlic follows SDSU, Illinois and Virginia Tech. Temperature notes: UMD (potatoes), UMN (sweet corn), UC ANR (peppers, hardening off), UMN (eggplant), Colorado State (tomatoes) and SDSU (hardening off).
Tips for Connecticut gardeners
- Watch soil temperature, not just the calendar — warm-season crops stall in cold soil. An inexpensive soil thermometer helps.
- Harden off transplants over 7–10 days before planting out (UC ANR, SDSU).
- Ask your local Cooperative Extension office about varieties and timing for your county; find it in the USDA NIFA land-grant university directory.
- Keep weeds down early — see our weed identification guide.
Frequently asked questions
When is the last frost in Connecticut?
Across the 289 Connecticut ZIP codes where frost comes in most years, the median last spring frost (32°F, NOAA 1991–2020) at the nearest station is Apr 20, and the middle 80% of ZIP codes range from Apr 12 to May 3. Check the average for your ZIP code, and remember frost can occur after the average date.
When can I plant tomatoes in Connecticut?
Transplant tomatoes outdoors 1–2 weeks after your average last frost, once nights stay above about 52°F (Colorado State). Typical dates: Zone 6 areas: May 2 – May 9; Zone 7 areas: Apr 23 – Apr 30.
What USDA zone is Connecticut?
Connecticut spans roughly USDA hardiness zones 6a–7b on the 2023 USDA map (by ZIP code, via PRISM). Hardiness zones describe winter low temperatures, not frost dates.
Other state planting calendars
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