Catonsville, MD planting zone & frost dates
Catonsville is in USDA hardiness zone 7b. The last spring frost usually comes around March 24 and the first fall frost around November 21, for a growing season of about 244 days.
Planting calendar for Catonsville
Dates are counted from the average last spring frost (March 24) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.
| Crop | When |
|---|---|
| Tomatoes | Start seeds indoors: Jan 27 – Feb 10 Transplant outdoors: Mar 31 – Apr 7 |
| Peppers | Start seeds indoors: Jan 13 – Jan 27 Transplant outdoors: Apr 7 – Apr 14 |
| Eggplant | Start seeds indoors: Jan 13 – Jan 27 Transplant outdoors: Apr 7 – Apr 14 |
| Broccoli | Start seeds indoors: Jan 13 – Jan 27 Transplant outdoors: Feb 24 – Mar 10 |
| Cabbage | Start seeds indoors: Jan 13 – Jan 27 Transplant outdoors: Feb 24 – Mar 10 |
| Onions (sets) | Plant outdoors: Feb 24 – Mar 10 |
| Peas | Sow outdoors: Feb 10 – Feb 24 |
| Spinach | Sow outdoors: Feb 10 – Feb 24 |
| Lettuce | Sow outdoors: Feb 24 – Mar 10 |
| Carrots | Sow outdoors: Feb 24 – Mar 10 |
| Potatoes | Plant outdoors: Feb 24 – Mar 10 |
| Beans | Sow outdoors: Mar 31 – Apr 7 |
| Sweet corn | Sow outdoors: Mar 31 – Apr 7 |
| Cucumbers | Sow outdoors: Mar 31 – Apr 7 |
| Squash & zucchini | Sow outdoors: Mar 31 – Apr 7 |
| Basil | Start seeds indoors: Feb 10 – Feb 24 Transplant outdoors: Mar 31 – Apr 7 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 26 (8 weeks before the average first fall frost on Nov 21).
Useful for zone 7b gardens
- Seed starting kit with dome — to start seeds indoors before the last frost
- LED grow light for seedlings — stops leggy seedlings
- Frost cloth / plant covers — for late spring and early fall frosts
- Soil thermometer — warm-season crops need soil above 60°F
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Mar 8 | Mar 24 | Apr 4 |
| First 32°F frost in fall is before | Dec 8 | Nov 21 | Nov 7 |
How to read it: in spring there is a 10% chance of a frost after April 4, so that is a safe date for tender plants. In fall there is a 10% chance of frost before November 7. A hard freeze (28°F) usually ends around March 11.
Hardiness zone by ZIP code in Catonsville
- 21228 zone 7b
Nearby cities
- Arbutus zone 7b, last frost Mar 24
- Woodlawn zone 7b, last frost Apr 2
- Elkridge zone 7b, last frost Apr 10
- West Elkridge zone 7b, last frost Apr 10
- Ellicott City zone 7b, last frost Apr 10
- Lochearn zone 7b, last frost Apr 2
- Gwynn Oak zone 7b, last frost Apr 2
- Ilchester zone 7b, last frost Apr 10
Questions
What growing zone is Catonsville, MD?
Catonsville is in USDA Plant Hardiness Zone 7b (average extreme winter low 5°F to 10°F), according to the USDA 2023 map.
When is the last frost in Catonsville?
The average last spring frost (32°F) in Catonsville is March 24. There is still a 10% chance of frost until April 4.
When can I plant tomatoes in Catonsville?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Mar 31 – Apr 7. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Md Sci Ctr Baltimore, MD (USW00093784), 10.6 km (6.6 mi) from the city center, elevation 6 m, based on 19 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.