What to plant this week in Philadelphia, PA
Philadelphia gardeners in zone 7b are officially in the garlic planting window as we edge toward our average last frost date of March 28. While most transplants wait for warmer soil, this week is critical to get your cloves in the ground before winter dormancy takes hold.
The next 7 days
Philadelphia, PAGrowing in Philadelphia right now
- Our city's dense urban heat islands can delay spring thaw by a week compared to surrounding suburbs; keep garlic mulched but check soil temp before forcing early sprouts.
- Philadelphia clay-loam soils retain moisture well during our humid springs, so ensure good drainage holes when planting hardy bulbs in raised beds or heavy garden plots.
- With average lows hovering near 5°F this time of year, apply a thick layer of straw over garlic beds to prevent freeze-thaw heaving common in our valley terrain.
Sow this week
1 crops- Garlic
Transplant this week
Nothing is due to go out this week.
Harvest soon
2 crops- Daikon Radish
- Garlic
Seasonal tips
- Finish harvesting cool-season crops like Daikon radish before temperatures drop too low.
- Plant cover crops or winter rye now to protect soil structure during the dormant season.
- Apply a thick layer of mulch around garlic plants to insulate bulbs from freezing ground.
Pest & disease watch
- Watch for winter moth larvae beginning their crawl-up phase on nearby maples and oaks as we approach mid-March.
- Early spring aphid colonies often establish quickly on the first tender lettuce or spinach seedlings started indoors now.
Watering this week
Water garlic lightly and only when the soil is dry, avoiding wetting the bulbs directly to prevent rot.
Store your freshly harvested Daikon radishes in a cool, humid place like a crisper drawer or sand-filled bin.
Philadelphia gardening questions
3Can I transplant my tomato starts this week in Philadelphia?
No, wait until after the average last frost date of March 28 and ensure soil temperatures reach at least 60°F. Transplanting too early risks stunting your plants during our unpredictable late March cold snaps.
When should I harvest my garlic planted last fall?
You can begin digging for side shoots or baby greens now, but full bulbs are not ready until mid-June. Look for the upper leaves turning yellow and falling over as the primary signal that your Philadelphia-grown cloves are mature.
What vegetables can I sow directly in my Philly garden this week?
This is the precise time to plant garlic cloves outdoors, but nothing else from your current zone 7b list requires immediate action. Save other sowable crops like peas or beans for later when our soil warms up further.
Other cities in zone 7b
12See the full zone 7b guide → · Plan your Philadelphia garden in SproutGuide →