Fall in zone 8aPhoto: George Chernilevsky, Public domain, via Wikimedia Commons
Frost dates for ZIP 21409 (Cape St. Claire, MD)
Average last spring and first fall frost dates with 10%, 50% and 90% odds, from NOAA's 1991–2020 climate normals for the nearest weather station, Annapolis Naf, MD (3 miles away).
- Average last spring frostMar 2350% chance of a 32°F freeze after this date
- Average first fall frostNov 2050% chance of a 32°F freeze by this date
- Growing season (frost-free)241 daysmedian, 32°F threshold
- USDA hardiness zone8a10 to 15°F avg. coldest night
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This week in your yard
As of Oct 18, 2026, from your frost dates, zone and soil temperature. Lawn timing · Vegetables · Pruning · Plants
Soil temperature now
2-inch depth
63°F 55°F or warmer
24-hour average · latest 60°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Powder Mill (22 mi).
4-inch depth
63°F 55°F or warmer
24-hour average · latest 58°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Powder Mill (22 mi).
Fall: Texas A&M AgriLife times fall pre-emergent (for winter weeds such as annual bluegrass) to soil cooling to about 70°F for several days. The 50–55°F band is the spring trigger. Always read and follow the product label.
7-day forecast and frost risk
The latest National Weather Service 7-day forecast and any Frost Advisory or Freeze Warning for 21409 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 63°F at 4 inches (estimated soil temperature, not a station reading). Fall pre-emergent (annual bluegrass, winter weeds): window open as soil cools through the 70s and 60s.
Fertilizer window
Lawn region: Transition zone. Timing only; always follow the product label.
- Bermudagrass (warm-season): Spring: Several weeks after the lawn is fully green (April–May) (about May 8 here, using green-up about 3–4 weeks after your average last frost); Summer: Every 4–6 weeks through mid-August (heaviest feeder of the group); Late: Light, low-nitrogen/high-potassium feeding about 4 weeks before first frost, or skip. Avoid: Heavy late-fall nitrogen (linked to spring dead spot).
- Tall fescue (cool-season): Early fall: September (main feeding); Late fall: November, while still green; Late winter: Optional light feeding February–March. Avoid: Feeding after mid-spring and through summer in the transition zone (stress and brown patch).
Plant now
- Arugula: fall sowing Sep 25–Oct 23
- Radish: fall sowing Oct 9–23
- Garlic: fall sowing Oct 9–Nov 6
- Shallot: fall sowing Oct 9–Nov 6
Prune now
No frost-timed pruning windows are open this week.
Your average first frost is Nov 20: skip heavy pruning in the 6–8 weeks before it, because new growth may not harden off in time.
Spring-flowering shrubs are pruned right after their flowers fade, not by date. See the pruning guide.
Last spring frost odds
| Chance of a 32°F freeze after this date | Date |
|---|---|
| 90% (early: most years still freeze after this) | Mar 8 |
| 50% (the "average" last frost) | Mar 23 |
| 10% (cautious: only 1 year in 10 freezes later) | Apr 6 |
Most gardeners plant frost-tender crops (tomatoes, peppers, basil) after the 50% date, and closer to the 10% date for less risk.
First fall frost odds
| Chance the first 32°F freeze has happened by this date | Date |
|---|---|
| 10% (early: 1 year in 10 freezes this soon) | Nov 4 |
| 50% (the "average" first frost) | Nov 20 |
| 90% (late: most years have frozen by now) | Dec 5 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | Apr 5 | Nov 6 |
| 32°F (freeze) | Mar 23 | Nov 20 |
| 28°F (hard freeze) | Mar 12 | Dec 3 |
n/a means NOAA did not publish a date at that threshold for this station (usually because it rarely gets that cold).
Vegetable planting calendar for 21409
Dates count from your average last spring frost (Mar 23) and first fall frost (Nov 20). Half of years have a frost after the spring date, so give tender crops (tomatoes, peppers, squash) some slack.
| Crop | Start indoors | Spring planting | Fall planting |
|---|---|---|---|
| Tomato | Jan 26–Feb 9 | Mar 30–Apr 13 (transplant) | Jul 24–Aug 21 (transplant) |
| Pepper (sweet and hot) | Jan 12–26 | Apr 6–20 (transplant) | Jul 31–Aug 21 (transplant) |
| Eggplant | Jan 12–26 | Apr 6–20 (transplant) | Jul 31–Aug 21 (transplant) |
| Tomatillo | Jan 26–Feb 9 | Mar 30–Apr 13 (transplant) | – |
| Lettuce | Jan 26–Feb 9 | Mar 2–23 (transplant) Feb 23–Apr 6 (sow outdoors) | Sep 25–Oct 16 (transplant) Sep 11–Oct 9 (sowing) |
| Spinach | – | Feb 9–Mar 2 (sow outdoors) | Sep 25–Oct 16 (sowing) |
| Kale | Jan 26–Feb 9 | Feb 23–Mar 9 (transplant) Feb 23–Mar 9 (sow outdoors) | Aug 28–Sep 25 (transplant) Aug 14–Sep 11 (sowing) |
| Collards | Jan 26–Feb 9 | Feb 23–Mar 23 (transplant) Feb 23–Mar 23 (sow outdoors) | Aug 28–Sep 25 (transplant) Aug 14–Sep 11 (sowing) |
| Broccoli | Jan 12–26 | Feb 23–Mar 9 (transplant) | Aug 14–Sep 11 (transplant) |
| Cabbage | Jan 12–26 | Feb 23–Mar 9 (transplant) | Aug 14–Sep 11 (transplant) |
| Cauliflower | Jan 12–26 | Mar 9–23 (transplant) | Aug 14–Sep 11 (transplant) |
| Brussels sprouts | Dec 29–Jan 12 | Feb 23–Mar 9 (transplant) | Jul 31–Aug 21 (transplant) |
| Kohlrabi | Jan 26–Feb 9 | Feb 23–Mar 9 (transplant) Feb 23–Mar 9 (sow outdoors) | Sep 11–25 (sowing) |
| Bok choy / Asian greens | – | Feb 23–Mar 9 (sow outdoors) | Sep 25–Oct 9 (sowing) |
| Arugula | – | Feb 23–Mar 23 (sow outdoors) | Sep 25–Oct 23 (sowing) |
| Mustard greens | – | Feb 23–Mar 16 (sow outdoors) | Sep 25–Oct 9 (sowing) |
| Swiss chard | Feb 9–23 | Mar 9–30 (transplant) Mar 9–Apr 6 (sow outdoors) | Sep 11–25 (sowing) |
| Beet | – | Feb 23–Mar 23 (sow outdoors) | Sep 11–25 (sowing) |
| Carrot | – | Mar 2–30 (sow outdoors) | Aug 28–Sep 11 (sowing) |
| Radish | – | Feb 16–Mar 30 (sow outdoors) | Oct 9–23 (sowing) |
| Turnip | – | Feb 23–Mar 16 (sow outdoors) | Sep 11–25 (sowing) |
| Parsnip | – | Mar 2–23 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Jan 26–Feb 23 (sow outdoors) | Aug 28–Sep 11 (sowing) |
| Onion (bulbing) | Dec 29–Jan 12 | Feb 9–23 (transplant) | – |
| Green onion / scallion | – | Feb 9–Mar 9 (sow outdoors) | Sep 11–25 (sowing) |
| Leek | Dec 29–Jan 12 | Feb 23–Mar 9 (transplant) | – |
| Garlic | – | – | Oct 9–Nov 6 (sowing) |
| Shallot | – | Feb 9–23 (transplant) | Oct 9–Nov 6 (sowing) |
| Potato | – | Feb 23–Mar 9 (transplant) | Jul 31–Aug 14 (transplant) |
| Sweet potato | – | Apr 13–27 (transplant) | – |
| Sweet corn | – | Mar 30–Apr 13 (sow outdoors) | – |
| Bean, bush (snap) | – | Mar 30–Apr 13 (sow outdoors) | Aug 28–Sep 11 (sowing) |
| Bean, pole | – | Mar 30–Apr 13 (sow outdoors) | – |
| Lima bean | – | Apr 6–20 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Apr 13–May 4 (sow outdoors) | – |
| Cucumber | Feb 23–Mar 2 | Mar 30–Apr 13 (transplant) Mar 30–Apr 13 (sow outdoors) | Aug 28–Sep 11 (sowing) |
| Summer squash / zucchini | Feb 23–Mar 2 | Mar 30–Apr 13 (transplant) Mar 30–Apr 13 (sow outdoors) | Aug 28–Sep 11 (sowing) |
| Winter squash | Feb 23–Mar 2 | Mar 30–Apr 13 (transplant) Mar 30–Apr 13 (sow outdoors) | – |
| Pumpkin | – | Mar 30–Apr 13 (sow outdoors) | – |
| Watermelon | Feb 23–Mar 2 | Apr 6–20 (transplant) Apr 6–20 (sow outdoors) | – |
| Cantaloupe / muskmelon | Feb 23–Mar 2 | Apr 6–20 (transplant) Apr 6–20 (sow outdoors) | – |
| Okra | Feb 9–23 | Apr 6–20 (transplant) Apr 6–20 (sow outdoors) | – |
| Celery | Dec 29–Jan 12 | Mar 30–Apr 6 (transplant) | – |
| Basil | Feb 9–23 | Mar 30–Apr 13 (transplant) Mar 30–Apr 13 (sow outdoors) | – |
| Cilantro | – | Mar 9–Apr 6 (sow outdoors) | Sep 25–Oct 9 (sowing) |
| Parsley | Jan 12–26 | Mar 9–23 (transplant) Mar 2–23 (sow outdoors) | – |
| Dill | – | Mar 23–Apr 6 (sow outdoors) | Sep 25–Oct 9 (sowing) |
| Sunflower | – | Mar 23–Apr 6 (sow outdoors) | – |
| Asparagus (crowns) | – | Feb 23–Mar 9 (transplant) | – |
| Rhubarb (crowns) | – | Feb 23–Mar 9 (transplant) | – |
| Strawberry (plants) | – | Feb 23–Mar 9 (transplant) | Sep 11–Oct 9 (transplant) |
Typical ranges from university extension planting calendars, adjusted to your frost dates. Probabilities, not guarantees. Fall windows that would overlap spring planting are left out, as are fall crops of frost-tender plants where the frost-free season is under 210 days.
Where these numbers come from
Station: Annapolis Naf, MD (NOAA GHCN-Daily ID USW00013752), elevation 8 ft, 2.7 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Annapolis Police Brks, MD | 4 mi | Mar 27 | Nov 13 |
| Stevensville 2SW, MD | 6 mi | Mar 29 | Nov 12 |
| Baltimore Wash Intl AP, MD | 16 mi | Apr 10 | Oct 31 |
The average last-frost dates of these stations span 18 days, a rough guide to local variation. See data sources & methods.
Frost questions for 21409
When is the last frost in 21409?
The average (50% chance) last spring freeze of 32°F for ZIP 21409 is March 23. For a more cautious planting date, use April 6, when only 1 year in 10 still sees a later freeze.
When is the first frost in 21409?
The average first fall freeze is November 20. In 1 year in 10 it comes by November 4.
What hardiness zone is 21409?
ZIP 21409 is in USDA zone 8a (10 to 15°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 21409 right now?
This page shows the latest 2-inch and 4-inch soil temperature from the nearest public soil station (USDA SCAN, NOAA USCRN or TexMesonet), or a labeled estimate when no station is close, against the 50–55°F spring pre-emergent band.
Nearby ZIP codes
21402 Naval Academy 21012 Arnold 21056 21405 21403 Annapolis Neck 21401 Parole 21122 Lake Shore 21146 Severna Park
Other ZIP codes in Anne Arundel County
20711 20714 20724 20733 20751 20755 20758 20764 20765 20776 20778 20779 21012 21032 21035 21037 21054 21056 21060 21061 21076 21077 21090 21108 All Anne Arundel County frost dates · Maryland frost dates
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Free. One weekly email plus alerts when your ZIP has a frost or a soil-temperature change worth acting on. After you submit, Kit (our email provider) sends a confirmation email: check your email and click the link to confirm. You aren't subscribed until you do. We collect only your email address and ZIP, sent to Kit to deliver The Dial. Unsubscribe anytime.