Gardening in Philadelphia-Camden-Wilmington, PA-NJ-DE-MD
This metro spans USDA zones 6b to 8a, so there is no single zone for Philadelphia-Camden-Wilmington, PA-NJ-DE-MD and anyone who gives you one is rounding. 60% of its ZIP codes are zone 7b; the rest are not.
Which zone you are in depends where you are
Philadelphia-Camden-Wilmington, PA-NJ-DE-MD covers 4 hardiness zones. A guide that gives the metro one zone has picked whichever is largest and rounded everyone else into it — which is fine for the 60% in zone 7b and wrong for the other 40%. Here is the actual split.
| Zone | ZIP codes | Share | |
|---|---|---|---|
| 7b | 224 | 60% | |
| 7a | 144 | 38% | |
| 6b | 5 | 1% | |
| 8a | 3 | 1% |
Zones are published per ZIP code, so yours is exact even though the metro's is not. The hardiness tool will tell you which one you are in.
Your freeze dates
Those are the earliest and latest medians among the 41 stations serving this metro — not an average, and not one station standing in for the rest. Half of years freeze later than a station's own median.
The spread is the point. Even in a metro that is one hardiness zone throughout, its stations disagree about the last spring freeze. Hardiness zone and frost date measure different things — a zone is the average annual coldest night, a freeze date is when the season turns — and a place can be uniform in one and varied in the other. Use the tools below with your own ZIP rather than the ends of this range.
Your growing season
NOAA publishes a growing-season length for each station, and across the 41 stations serving Philadelphia-Camden-Wilmington, PA-NJ-DE-MD it runs 169–232 days . That figure is published, not computed from the two freeze dates — subtracting one from the other gives the wrong answer wherever a season crosses New Year. Mean summer high (June–August) runs 81–87 °F , below the 90 °F point where cool-season crops reliably bolt.
When to start seeds in Philadelphia-Camden-Wilmington, PA-NJ-DE-MD
Every spring job for 63 crop dates, counted from this metro's own last spring freeze. Each is a range across all 41 stations — the earliest and latest that job falls anywhere in the metro — because no one station speaks for the whole area.
| Crop | Job | When | Offset |
|---|---|---|---|
| Green Onions | Start indoors | February 2 – March 4 | 8 weeks before |
| Peppers | Start indoors | February 2 – March 4 | 8 weeks before |
| Broccoli | Start indoors | February 16 – March 18 | 6 weeks before |
| Cabbage | Start indoors | February 16 – March 18 | 6 weeks before |
| Collards | Start indoors | February 16 – March 18 | 6 weeks before |
| Kale | Start indoors | February 16 – March 18 | 6 weeks before |
| Leaf Lettuce | Start indoors | February 16 – March 18 | 6 weeks before |
| Peas | Direct sow | February 16 – March 18 | 6 weeks before |
| Spinach | Direct sow | February 16 – March 18 | 6 weeks before |
| Sweet Potato | Start indoors | February 16 – March 18 | 6 weeks before |
| Tomatoes | Start indoors | February 16 – March 18 | 6 weeks before |
| Bok Choy | Start indoors | February 23 – March 25 | 5 weeks before |
| Kohlrabi | Start indoors | February 23 – March 25 | 5 weeks before |
| Swiss Chard | Start indoors | February 23 – March 25 | 5 weeks before |
| Arugula | Direct sow | March 2 – April 1 | 4 weeks before |
| Baby Salad Greens | Direct sow | March 2 – April 1 | 4 weeks before |
| Beets | Direct sow | March 2 – April 1 | 4 weeks before |
| Green Onions | Direct sow | March 2 – April 1 | 4 weeks before |
| Mustard Greens | Direct sow | March 2 – April 1 | 4 weeks before |
| Okra | Start indoors | March 2 – April 1 | 4 weeks before |
| Radishes | Direct sow | March 2 – April 1 | 4 weeks before |
| Turnips | Direct sow | March 2 – April 1 | 4 weeks before |
| Cabbage | Set out | March 9 – April 8 | 3 weeks before |
| Carrots | Direct sow | March 9 – April 8 | 3 weeks before |
| Collards | Direct sow | March 9 – April 8 | 3 weeks before |
| Collards | Set out | March 9 – April 8 | 3 weeks before |
| Cucumbers | Start indoors | March 9 – April 8 | 3 weeks before |
| Green Onions | Set out | March 9 – April 8 | 3 weeks before |
| Kale | Direct sow | March 9 – April 8 | 3 weeks before |
| Kale | Set out | March 9 – April 8 | 3 weeks before |
| Kohlrabi | Direct sow | March 9 – April 8 | 3 weeks before |
| Kohlrabi | Set out | March 9 – April 8 | 3 weeks before |
| Leaf Lettuce | Direct sow | March 9 – April 8 | 3 weeks before |
| Pumpkins | Start indoors | March 9 – April 8 | 3 weeks before |
| Summer Squash | Start indoors | March 9 – April 8 | 3 weeks before |
| Winter Squash | Start indoors | March 9 – April 8 | 3 weeks before |
| Zucchini | Start indoors | March 9 – April 8 | 3 weeks before |
| Bok Choy | Direct sow | March 16 – April 15 | 2 weeks before |
| Bok Choy | Set out | March 16 – April 15 | 2 weeks before |
| Broccoli | Set out | March 16 – April 15 | 2 weeks before |
| Cilantro | Direct sow | March 16 – April 15 | 2 weeks before |
| Leaf Lettuce | Set out | March 16 – April 15 | 2 weeks before |
| Swiss Chard | Direct sow | March 16 – April 15 | 2 weeks before |
| Swiss Chard | Set out | March 16 – April 15 | 2 weeks before |
| Dill | Direct sow | March 23 – April 22 | 1 week before |
| Bush Beans | Direct sow | April 6 – May 6 | 1 week after |
| Cucumbers | Set out | April 6 – May 6 | 1 week after |
| Pumpkins | Direct sow | April 6 – May 6 | 1 week after |
| Pumpkins | Set out | April 6 – May 6 | 1 week after |
| Summer Squash | Direct sow | April 6 – May 6 | 1 week after |
| Summer Squash | Set out | April 6 – May 6 | 1 week after |
| Sweet Corn | Direct sow | April 6 – May 6 | 1 week after |
| Tomatoes | Set out | April 6 – May 6 | 1 week after |
| Winter Squash | Direct sow | April 6 – May 6 | 1 week after |
| Winter Squash | Set out | April 6 – May 6 | 1 week after |
| Zucchini | Direct sow | April 6 – May 6 | 1 week after |
| Zucchini | Set out | April 6 – May 6 | 1 week after |
| Cucumbers | Direct sow | April 13 – May 13 | 2 weeks after |
| Okra | Direct sow | April 13 – May 13 | 2 weeks after |
| Okra | Set out | April 13 – May 13 | 2 weeks after |
| Peppers | Set out | April 13 – May 13 | 2 weeks after |
| Southern Peas | Direct sow | April 13 – May 13 | 2 weeks after |
| Sweet Potato | Set out | April 13 – May 13 | 2 weeks after |
The week offsets are conventional extension guidance and vary by variety; the freeze dates they are counted from are measured. For a single date rather than a range, run when do I start my seeds? with your own ZIP code.
What survives the winter changes across Philadelphia-Camden-Wilmington, PA-NJ-DE-MD
Of 74 perennial fruits, nuts, berries, vegetables and herbs, 58 come through the winter in zone 7a and only 51 in zone 6b. That is a different garden at each end of the same metro.
| Zone | ZIPs | Survive | Fail for being too warm |
|---|---|---|---|
| 6b | 5 | 51 of 74 | 0 |
| 7a | 144 | 58 of 74 | 1 |
| 7b | 224 | 56 of 74 | 3 |
| 8a | 3 | 57 of 74 | 8 |
The last column is the counterintuitive one, and it is why the totals do not simply rise as the winters get milder. Most temperate fruit needs a documented number of hours below about 45 °F to break dormancy and set a crop, so an apple fails in a winter that is too warm; currants and rhubarb cook in the summer heat that comes with it. See the full list with reasons.
The 41 stations behind these numbers
Every figure above comes from these, and each is named so you can check it. Distances vary by ZIP code, so the tools report yours rather than this page guessing.
| Station | NOAA ID | Last spring freeze | First fall freeze | Season |
|---|---|---|---|---|
| Aberdeen Phillips FLD, MD | USW00013701 | April 10 | October 30 | 201 days |
| Atlantic City INTL AP, NJ | USW00093730 | April 18 | October 29 | 190 days |
| Avondale 2 N, PA | USW00003761 | April 19 | October 26 | 189 days |
| Bucksville, PA | USC00361080 | April 29 | October 16 | 170 days |
| Chestertown, MD | USC00181750 | April 3 | November 5 | 217 days |
| Coatesville 2 W, PA | USC00361591 | April 19 | October 25 | 190 days |
| Conowingo Dam, MD | USC00182060 | April 3 | November 6 | 217 days |
| Dover, DE | USC00072730 | April 4 | November 4 | 214 days |
| Doylestown AP, PA | USW00054786 | April 13 | October 30 | 198 days |
| Glassboro 2 NE, NJ | USC00283291 | April 8 | November 1 | 205 days |
| Glenmoore, PA | USC00363321 | April 11 | November 1 | 205 days |
| Graterford 1 E, PA | USC00363437 | April 24 | October 15 | 173 days |
| Hammonton 1 NE, NJ | USC00283662 | April 14 | October 27 | 196 days |
| Hopewell Morgantown, PA | USC00364076 | April 16 | October 27 | 193 days |
| Indian Mills 2 W, NJ | USC00284229 | April 28 | October 15 | 169 days |
| Lambertville, NJ | USC00284635 | April 16 | October 19 | 185 days |
| Marcus Hook, PA | USC00365390 | March 30 | November 16 | 230 days |
| Moorestown, NJ | USC00285728 | April 12 | November 1 | 200 days |
| Mt Holly S Jersey AP, NJ | USW00093780 | April 15 | October 28 | 195 days |
| Neshaminy Falls, PA | USC00366194 | April 21 | October 25 | 185 days |
| Newark Ag Farm, DE | USC00076410 | April 7 | November 2 | 208 days |
| Norristown, PA | USC00366370 | April 8 | October 31 | 203 days |
| Octoraro Lake, PA | USC00366508 | April 26 | October 22 | 179 days |
| Pennsauken 1N, NJ | USC00286864 | April 15 | October 31 | 199 days |
| Phila Franklin Inst, PA | USC00366886 | March 30 | November 17 | 232 days |
| Philadelphia INTL AP, PA | USW00013739 | April 2 | November 10 | 224 days |
| Philadelphia NE AP, PA | USW00094732 | April 4 | November 7 | 216 days |
| Philadelphia/Mt Holly Wfo, NJ | USC00286964 | April 15 | October 29 | 196 days |
| Phoenixville 1 E, PA | USC00366927 | April 18 | October 27 | 192 days |
| Pottstown Limerick AP, PA | USW00054782 | April 20 | October 23 | 186 days |
| Rodale Rsch Ctr, PA | USC00367578 | April 26 | October 14 | 171 days |
| Seabrook Farms, NJ | USC00287936 | April 10 | November 1 | 205 days |
| Sellersville, PA | USC00367938 | April 26 | October 17 | 175 days |
| Springtown 1 Nne, PA | USC00368400 | April 21 | October 22 | 184 days |
| Trenton Mercer Co AP, NJ | USW00014792 | April 10 | November 1 | 202 days |
| Trenton State College, NJ | USC00288880 | April 17 | October 28 | 192 days |
| W Chester 2 NW, PA | USC00369464 | April 26 | October 18 | 174 days |
| Willow Grove Nas, PA | USW00014793 | April 11 | November 1 | 205 days |
| Wilmington New Castle Co AP, DE | USW00013781 | April 7 | November 1 | 209 days |
| Wilmington Porter Rsch, DE | USC00079605 | April 7 | November 4 | 209 days |
| Woodstown Pittsgrov 4E, NJ | USC00289910 | April 11 | November 3 | 206 days |
These are medians, not averages — NOAA publishes freeze dates as a probability distribution, and half of years freeze later than the date shown.
Work out your own dates
Each of these takes a ZIP code and answers for that ZIP alone, citing the station it used and how far away it is. There is a ZIP box in the header of every page.
- What survives my winter?
Runs on the hardiness zone, so it answers for all of Philadelphia-Camden-Wilmington, PA-NJ-DE-MD at once — zone across 74 perennial fruits, berries, vegetables and herbs.
- When do I start my seeds?
Dates every spring job from your own last freeze — sow indoors, set out, direct sow.
- When do I sow the next round?
How often each crop is worth re-sowing, and when the next sowing is due.
- What can I still plant?
Counts the growing days left before your first fall freeze, crop by crop.
Where these numbers come from
The hardiness zone is the USDA 2023 Plant Hardiness Zone Map, published per ZIP code by PRISM at Oregon State. The freeze dates are NOAA's 1991–2020 Climate Normals, read from every station whose normals cover a ZIP code in this metro. Nothing here is estimated, and no station stands in for another.
This page names no single station on purpose. Picking one to represent a metro sounds reasonable and is not: the station serving the most ZIP codes is an artifact of where ZIP centroids happen to fall, and it selects a lock on the Monongahela for Pittsburgh and a far southern suburb for Chicago. A range across every station is true; a single cited date for a whole metro is not.