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When to plant broccoli in Baltimore

How to grow BroccoliBaltimore climate
Where are you growing?

Comfortable

Comfortable in greenhouse

Comfortable in a cold frame

Broccoli in Baltimore is a good fit outdoors. The suitable growing window of 139 days covers the 55–75 days this plant usually needs.

Start indoors
December 7 – January 31
Transplant outside
January 25 – March 21; August 30 – September 18
Harvest
March 21 – June 4
Season vs crop
139 grow days vs 55–75 needed
Typical frost (last spring – first fall)
March 8 – November 19

Broccoli in Baltimore is a good fit outdoors. The suitable growing window of 139 days covers the 55–75 days this plant usually needs.

Planting conditions

Broccoli planting activities across the year: Start indoors, Harden off, Transplant outside, Grow outdoors, HarvestJFMAMJJASOND~Mar 8~Nov 19
  • Start indoors
  • Harden off
  • Transplant outside
  • Grow outdoors
  • Harvest
Local activity windows for this place and growing method. Blue fill is usually too cold for this plant. Dashed lines are typical last and first frost.
Suitable growing days in a row139
Days to harvest55–75 days from transplant
Dec 7 – Jan 31
Start indoors
Jan 18 – Jan 24
Harden off
January 25
Transplant outside
Jan 26 – Mar 20
Grow outdoors
Mar 21 – Jun 4
Harvest
ActivityWindowNotes
Start indoorsDec 7 – Jan 31Sow indoors before the outdoor window.
Harden offJan 18 – Jan 24Acclimate seedlings outdoors before planting.
Transplant outsideJanuary 25Move plants outside on this day (start of the plant-out window).
Grow outdoorsJan 26 – Mar 20Plants grow outdoors until harvest.
HarvestMar 21 – Jun 4Expected harvest from typical days to harvest.
Blue fill is usually too cold for this plant. Dashed lines are typical last and first frost. Adjust a week or two for your conditions.

Planting and growing across the year

Planting is the sow / plant-out window. Growing is daytime air versus this plant’s ideal (59 – 75 °F) and tolerable (39 – 81 °F) ranges.

Broccoli planting and growing weeks in BaltimoreJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECPlantingGrowing
Planting uses sow / plant-out rules (frost, soil germination, night, and last-sow): green when plantable, blue diagonal when nights or soil are too cold, amber cross-hatch when too hot, faint for other calendar limits. Growing shows daytime air against this plant’s ideal and tolerable ranges across the year.

Key dates

Typical last spring frostMarch 8
Safer last spring frostMarch 8
Typical first fall frostNovember 19
Safer first fall frostNovember 19
Frost-free days255
Earliest indoor seed startDecember 7
Latest indoor seed startJanuary 31
Transplant outdoorsJanuary 25 – March 21
Direct sow windownot recommended here
Suitable growing windowJanuary 25 – June 12 (139 days)
Expected harvestMarch 21 – June 4

How these dates are judged

Ideal conditions
Daytime air from 59 – 75 °F.
Suitable conditions
Daytime air from 39 – 81 °F.
Last frost and first frost
Typical spring and fall frost dates for Baltimore, shown in the key dates.
Days to harvest
55–75 days from transplant, from typical days to harvest.
Sowing window
Dated sow and harvest bars use frost dates, soil minima, night limits, and last-sow count-back from typical crop timing. The year strip and weekly chart use the same window: air ratings only colour weeks inside it.

Growing window for Broccoli: Jan 25 – Jun 12; Aug 30 – Nov 27 (229 days)

Planting window for Broccoli: Jan 25 – Mar 21; Aug 30 – Sep 18 (76 days)

Usually too cold: Nov 30 – Dec 31

Outdoors: weekly temperatures and windows

Temperatures across the year for Baltimore. Shaded bands are this plant’s ideal and tolerable daytime air ranges. Growing is daytime air suitability; Planting is sow / plant-out conditions (same colour language). Window brackets mark each stretch.

JanFebMarAprMayJunJulAugSepOctNovDec−20 °C−4 °F−10 °C14 °F0 °C32 °F10 °C50 °F20 °C68 °F30 °C86 °F40 °C104 °FTolerable 4–27 °CTolerable 39–81 °FIdeal 15–24 °CIdeal 59–75 °FWindowGrowingJan 25 – Jun 12; Aug 30 – Nov 27PlantingJan 25 – Mar 21; Aug 30 – Sep 18Last frost ~Mar 8First frost ~Nov 19
  • Ideal range
  • Tolerable range
  • Possible min to max
  • Average min to max
  • Suitable
  • Tolerable
  • Too cold
  • Too hot

Selected week · tap a week or use the arrows

Week 4 · Jan 19 – Jan 25

Average 25 to 38 °F · Possible 4 to 58 °F

Growing: too cold

Planting: too cold

A week is in range when its average low and high sit inside the tolerance band 39 to 81 °F; it is suitable when that average range also overlaps the ideal 59 to 75 °F band and possible readings stay within 39 °F to 81 °F. Crossing a possible limit, or missing the ideal band, makes it tolerable; a possible low below 39 °F makes it tolerable. When a sowing window is calculated, weeks outside that window are uncoloured even if air is in range.

Based on average frost dates.

Show all 53 weeks
Cover method weekly charts

Outdoor weekly chart is above. Open a cover chart only if you grow under fleece, a cold frame, or an unheated greenhouse.

Other plants for Baltimore

Calculated by Plan & Plant · Method · Data 2019–2026

Frost and suitability dates are typical figures from climate statistics. Microclimates vary; they are not a guarantee.

How we calculated this
  • Data: ERA5-Land via Open-Meteo, cell 39.29, -76.61, years 2019–2026 (not a 30-year climate normal yet).
  • Typical and safer dates: Typical last frost is the date after which half of winters in this sample had no more frost; safer is later in the sample so fewer winters still frosted.
  • Crop rule: Local windows for Broccoli from frost dates, temperature ratings, and crop timing rules.
  • Confidence: Provisional — short or thin sample for this place.
  • Full methodology (algorithm 2026-10-season-6).

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