When to Plant in Baltimore, MD: Planting Calendar & Frost Dates
Quick answer
In Baltimore (ZIP 21202), the median last spring frost is Mar 24 and the first fall frost is Nov 21. Start tomato seeds indoors Jan 27 – Feb 10 and transplant them Mar 31 – Apr 7; sow peas Feb 10 – Feb 24; plant garlic Nov 7 – Dec 12.
For ZIP 21202 in Baltimore, the nearest NOAA weather station with freeze records is Maryland Science Center Baltimore (NOAA name: Md Sci Ctr Baltimore, MD), 1.1 miles away. Its median last spring frost (32°F, NOAA 1991–2020) is Mar 24 and its median first fall frost is Nov 21, leaving about 242 frost-free days. ZIP 21202 is in USDA hardiness zone 8a. The last frost here comes the same day as the zone 8 median (Mar 24), and the season is 11 days longer than the zone’s typical 231 days. Across Maryland’s 477 ZIP codes with frost dates, the median last frost is Apr 5, so Baltimore’s comes 12 days earlier than that.
Station and dates: NOAA NCEI U.S. Climate Normals 1991–2020, 32°F at 50% probability, for the station nearest the center of ZIP 21202. Zone: 2023 USDA Plant Hardiness Zone Map (PRISM data by ZIP code).
Next 30 days in Baltimore
See what to plant this month in the planner for ZIP 21202.
Key planting dates for Baltimore
| Key date | When in Baltimore | How it is counted |
|---|---|---|
| Sow peas | Feb 10 – Feb 24 | 4–6 weeks before last frost (Mar 24) |
| Start tomatoes indoors | Jan 27 – Feb 10 | 6–8 weeks before last frost (Mar 24) |
| Transplant tomatoes | Mar 31 – Apr 7 | 1–2 weeks after last frost (Mar 24) |
| Sow beans and squash | Mar 31 – Apr 7 | 1–2 weeks after last frost (Mar 24) |
| Sow fall lettuce | Sep 26 – Oct 10 | 6–8 weeks before first fall frost (Nov 21) |
| Plant garlic | Nov 7 – Dec 12 | 2 weeks before to 3 weeks after first fall frost, while the soil is still workable (SDSU, Illinois, Virginia Tech) (Nov 21) |
| Plant tulip bulbs | Nov 7 – Dec 19 | 2 weeks before to 4 weeks after first fall frost (our approximation of when soil falls below 60°F; Rutgers) (Nov 21) |
Baltimore vegetable and flower planting calendar
Every date range below is counted from Baltimore’s median frost dates (Mar 24 and Nov 21) with the same rules as our planner, and rows run in calendar order. In about half of years a frost still comes after the spring date.
| Plant | Task | Dates (and how they are counted) | Expected harvest (estimate) |
|---|---|---|---|
| Broccoli | Start indoors | Jan 13 – Jan 278–10 weeks before last frost (avg. Mar 24) | — |
| Cabbage | Start indoors | Jan 13 – Jan 278–10 weeks before last frost (avg. Mar 24) | — |
| Kale | Start indoors | Jan 13 – Jan 278–10 weeks before last frost (avg. Mar 24) | — |
| Tomatoes | Start indoors | Jan 27 – Feb 106–8 weeks before last frost (avg. Mar 24) | — |
| Peppers | Start indoors | Jan 27 – Feb 106–8 weeks before last frost (avg. Mar 24) | — |
| Eggplant | Start indoors | Jan 27 – Feb 106–8 weeks before last frost (avg. Mar 24) | — |
| Peas | Direct sow | Feb 10 – Feb 244–6 weeks before last frost (avg. Mar 24) | Apr 11 – May 1560–80 days from seeding |
| Spinach | Direct sow | Feb 10 – Feb 244–6 weeks before last frost (avg. Mar 24) | Mar 27 – Apr 2545–60 days from seeding |
| Basil | Start indoors | Feb 10 – Feb 244–6 weeks before last frost (avg. Mar 24) | — |
| Radishes | Direct sow | Feb 17 – Mar 102–5 weeks before last frost (avg. Mar 24) | Mar 9 – Apr 920–30 days from seeding |
| Lettuce | Direct sow | Feb 24 – Mar 102–4 weeks before last frost (avg. Mar 24) | Apr 25 – May 2960–80 days from seeding |
| Onions (sets/transplants) | Plant sets/transplants | Feb 24 – Mar 102–4 weeks before last frost (avg. Mar 24) | May 20 – Jul 885–120 days from planting |
| Broccoli | Transplant | Feb 24 – Mar 102–4 weeks before last frost (avg. Mar 24) | Apr 15 – May 1950–70 days from transplanting |
| Cabbage | Transplant | Feb 24 – Mar 102–4 weeks before last frost (avg. Mar 24) | May 5 – Jun 870–90 days from transplanting |
| Kale | Transplant | Feb 24 – Mar 102–4 weeks before last frost (avg. Mar 24) | — |
| Marigolds | Start indoors | Mar 3 – Mar 240–3 weeks before last frost (3–4 weeks before setting out; Univ. of Idaho) (avg. Mar 24) | — |
| Zinnias | Start indoors | Mar 3 – Mar 240–3 weeks before last frost (3–4 weeks before setting out; Univ. of Idaho) (avg. Mar 24) | — |
| Potatoes | Plant seed potatoes | Mar 10 – Mar 171–2 weeks before last frost (avg. Mar 24) | Jun 3 – Jul 585–110 days from planting |
| Marigolds | Direct sow / transplant | Mar 24 – Apr 7from the last frost to 2 weeks after (Univ. of Idaho) (avg. Mar 24) | — |
| Zinnias | Direct sow / transplant | Mar 24 – Apr 7from the last frost to 2 weeks after (Univ. of Idaho) (avg. Mar 24) | — |
| Tomatoes | Transplant | Mar 31 – Apr 71–2 weeks after last frost (avg. Mar 24) | Jun 9 – Jul 670–90 days from transplanting |
| Beans (bush & pole) | Direct sow | Mar 31 – Apr 71–2 weeks after last frost (avg. Mar 24) | May 15 – Jun 1645–70 days from seeding |
| Sweet corn | Direct sow | Mar 31 – Apr 71–2 weeks after last frost (avg. Mar 24) | Jun 4 – Jul 665–90 days from seeding |
| Cucumbers | Direct sow | Mar 31 – Apr 71–2 weeks after last frost (avg. Mar 24) | May 10 – Jun 1140–65 days from seeding |
| Squash | Direct sow | Mar 31 – Apr 71–2 weeks after last frost (avg. Mar 24) | May 10 – May 2740–50 days from seeding |
| Pumpkins | Direct sow | Mar 31 – Apr 141–3 weeks after last frost (avg. Mar 24) | Jun 19 – Jul 2380–100 days from seeding |
| Basil | Transplant | Mar 31 – Apr 71–2 weeks after last frost (avg. Mar 24) | May 12 – May 1942 days from transplanting |
| Peppers | Transplant | Apr 7 – Apr 142–3 weeks after last frost (avg. Mar 24) | Jun 11 – Jun 2865–75 days from transplanting |
| Eggplant | Transplant | Apr 7 – Apr 142–3 weeks after last frost (avg. Mar 24) | Jun 16 – Jul 1370–90 days from transplanting |
| Broccoli | Fall transplant | Aug 29 – Sep 1210–12 weeks before first fall frost (avg. Nov 21) | Oct 18 – Nov 2150–70 days from transplanting |
| Cabbage | Fall transplant | Aug 29 – Sep 1210–12 weeks before first fall frost (avg. Nov 21) | Nov 7 – Dec 1170–90 days from transplanting |
| Kale | Fall sow | Sep 12 – Sep 268–10 weeks before first fall frost (avg. Nov 21) | Nov 1 – Dec 550–70 days from seeding |
| Lettuce | Fall sow | Sep 26 – Oct 106–8 weeks before first fall frost (avg. Nov 21) | Nov 25 – Dec 2960–80 days from seeding |
| Spinach | Fall sow | Oct 3 – Oct 244–7 weeks before first fall frost (Virginia Tech) (avg. Nov 21) | Nov 17 – Dec 2345–60 days from seeding |
| Radishes | Fall sow | Oct 10 – Oct 244–6 weeks before first fall frost (avg. Nov 21) | Oct 30 – Nov 2320–30 days from seeding |
| Daffodils | Fall plant bulbs | Oct 24 – Dec 54 weeks before to 2 weeks after first fall frost (our approximation of when soil falls below 60°F; Rutgers) (avg. Nov 21) | — |
| Tulips | Fall plant bulbs | Nov 7 – Dec 192 weeks before to 4 weeks after first fall frost (our approximation of when soil falls below 60°F; Rutgers) (avg. Nov 21) | — |
| Garlic | Fall plant cloves | Nov 7 – Dec 122 weeks before to 3 weeks after first fall frost, while the soil is still workable (SDSU, Illinois, Virginia Tech) (avg. Nov 21) | Jul 15 – Sep 8 (next year)250–270 days from planting |
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).
Harvest estimates add days to harvest from these sources to each planting window, and stop at the first fall frost for frost-tender crops: 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.
Frost dates across Baltimore’s ZIP codes
Across Baltimore’s 23 ZIP codes, the median last spring frost ranges from Mar 24 to Apr 2 and the median first fall frost from Nov 7 to Nov 21, depending on which of 2 NOAA stations is nearest. This page uses ZIP 21202, which is in the group most Baltimore ZIP codes share.
| Nearest NOAA station | Last spring frost | First fall frost | Baltimore ZIP codes |
|---|---|---|---|
| Maryland Science Center Baltimore (NOAA name: Md Sci Ctr Baltimore, MD) | Mar 24 | Nov 21 | 14: 21201, 21202, 21205, 21206, 21213, 21217, 21223, 21224, 21226, 21229, 21230, 21231, 21233, 21287 |
| Cylburn | Apr 2 | Nov 7 | 9: 21210, 21211, 21212, 21214, 21215, 21216, 21218, 21239, 21251 |
Which ZIP codes count as Baltimore: the 23 ZIP Code Tabulation Areas (2020 ZCTAs) with at least half of their land area inside Baltimore city limits, from the U.S. Census Bureau, 2020 ZCTA to Place Relationship File. ZCTAs are the Census Bureau’s approximations of USPS ZIP Code areas, so this list may not match every USPS ZIP code. Each ZIP code’s dates are the ones our planner shows for it.
How Baltimore compares
| Area | Median last spring frost | Median first fall frost | Frost-free days |
|---|---|---|---|
| Baltimore (ZIP 21202) | Mar 24 | Nov 21 | 242 |
| Maryland (median of 477 ZIP codes) | Apr 5 | Nov 5 | 214 |
| USDA zone 8 (median of 5,253 ZIP codes) | Mar 24 | Nov 10 | 231 |
How this table is built: each ZIP code is matched to its nearest NOAA 1991–2020 freeze-data station (within 60 miles); state and zone rows are medians across those ZIP codes. Zones are the 2023 USDA zones by ZIP code (PRISM).
More for Baltimore gardeners
- Your own ZIP: open the planner for ZIP 21202 and change the ZIP to yours for its own station and dates.
- Maryland: When to plant in Maryland, with frost dates across the state.
- USDA zone 8a: our zone 8 planting guide.
- Frost tonight? How to protect plants from frost.
Wilmington Philadelphia Pittsburgh Boston Chicago Minneapolis Denver Dallas Richmond Atlanta Seattle Phoenix Los Angeles Miami All cities
Frequently asked questions
When is the last frost in Baltimore?
For ZIP 21202 in Baltimore, the nearest NOAA 1991–2020 normals station (Maryland Science Center Baltimore, 1.1 miles away) has a median last spring frost (32°F) of Mar 24. Across Baltimore’s 23 ZIP codes it ranges from Mar 24 to Apr 2. In about half of years a frost still comes after that date, so tender plants are safer 1–2 weeks later.
When should I plant tomatoes in Baltimore?
Start tomato seeds indoors Jan 27 – Feb 10 (6–8 weeks before the last frost) and transplant them outdoors Mar 31 – Apr 7 (1–2 weeks after it), once nights stay above about 52°F (Colorado State).
What is the first fall frost date in Baltimore?
The median first fall frost (32°F) for ZIP 21202 is Nov 21, about 242 days after the last spring frost. Across Baltimore’s ZIP codes it ranges from Nov 7 to Nov 21. Sow fall lettuce Sep 26 – Oct 10 and plant garlic Nov 7 – Dec 12.
What USDA zone is Baltimore in?
ZIP 21202 in Baltimore is in USDA hardiness zone 8a on the 2023 USDA map (by ZIP code, via PRISM). Hardiness zones describe winter low temperatures, not frost dates.
Sources
- NOAA National Centers for Environmental Information: U.S. Climate Normals 1991–2020
- USDA Agricultural Research Service, Plant Hardiness Zone Map: 2023 USDA Plant Hardiness Zone Map
- UNH Extension: When to Plant Your Vegetable Garden
- Rutgers NJAES Cooperative Extension: Rutgers FS787, Starting Vegetable Seeds Indoors; FS1220: Spring Flowering Bulbs (Rutgers NJAES)
- Virginia Cooperative Extension (Virginia Tech): Virginia Cooperative Extension 426-331, Virginia’s Home Garden Vegetable Planting Guide
- University of Maryland Extension: Vegetable Planting Calendar; Growing Potatoes in a Home Garden; Growing Onions in a Home Garden; Growing Garlic in a Home Garden; Growing Basil in a Home Garden
- University of Idaho Extension: CIS 1209
- South Dakota State University Extension: Planting Garlic; Harden Your Transplants Prior To Planting Your Garden
- University of Illinois Extension: Ready, Set, Garlic!
- University of Minnesota Extension: Growing sweet corn in home gardens; Growing eggplant in home gardens
- University of California Agriculture and Natural Resources (UC ANR): Growing Peppers
- Colorado State University Extension: Growing tomatoes
- UF/IFAS Extension: Florida Vegetable Gardening Guide (SP103/VH021), Table 1, “Days to Harvest”
- U.S. Census Bureau: 2020 ZCTA to Place Relationship File