USDA Hardiness Zone 7b
Frost Dates for 21227 — Baltimore, Maryland
Averages from MD Sci Ctr Baltimore, MD US, the nearest reporting station, 4.6 miles away.
Plant tender crops after March 24, and expect the first autumn freeze around November 21. That leaves about 244 frost-free days.
- Last spring frost
- March 24
- First fall frost
- November 21
- Growing season
- 244 days
- Hardiness zone
- 7b
50% probability
50% probability
frost-free
5 to 10°F annual low
Planting calendar for 21227
| When | What to do |
|---|---|
| January 13 – January 27 | Start peppers and aubergines indoors They need eight to ten weeks under lights before they can go out. |
| January 27 – February 10 | Start tomatoes indoors Six to eight weeks gives a transplant big enough to set fruit early. |
| February 24 – March 10 | Sow peas, spinach, lettuce, radish outdoors These tolerate light frost and prefer to germinate in cool soil. |
| March 24 onward | Transplant tomatoes, peppers, basil, squash, cucumbers The average last freeze has passed — still watch the actual forecast. |
| by August 29 | Sow the autumn crop of carrots, beets and brassicas They need about twelve weeks to size up before growth stops. |
| by November 7 | Harvest tender crops, or be ready to cover them A first freeze two weeks early is well within normal variation. |
| November 21 onward | Plant garlic, mulch beds, lift tender bulbs Garlic wants a cold spell; bare soil loses structure over winter. |
What these dates mean
Wait until after March 24 to put tender plants — tomatoes, peppers, basil, squash — in the ground. That is the date by which half of years in Baltimore, Maryland are past their last freeze. Harvest before November 21, which leaves roughly 244 frost-free days.
ZIP 21227 sits in USDA hardiness zone 7b, meaning the average coldest night of the year falls between 5 to 10°F. Zone decides what survives the winter; frost dates decide when to plant each spring. They are different questions, and a plant can pass one and fail the other.
These are thirty-year NOAA averages for 1991–2020, not a forecast. Any individual year can frost two to three weeks either side of these dates, so check the actual forecast before planting out.