What to plant this week in Philadelphia, PA
Philadelphia gardeners in zone 7b are transitioning from late winter cleanup to early spring action, with the average last frost date falling around March 28. This week marks a critical window for sowing heat-loving crops like bush beans and yellow summer squash that thrive after the soil warms up post-frost.
The next 7 days
Philadelphia, PAGrowing in Philadelphia right now
- Philadelphia's heavy clay soils retain moisture well but require amendments like compost to prevent waterlogging during our typical April spring rains before planting warm-season seeds.
- While the city's urban heat island effect slightly delays frost dates compared to rural counties, always wait until after March 28 before putting out sensitive seedlings or starting transplants outdoors.
- Take advantage of the upcoming warm spells to sow zucchini and French marigolds directly into garden beds or raised containers where drainage is improved.
Sow this week
4 crops- Bush Bean
- French Marigold
- Yellow Summer Squash
- Zucchini
Transplant this week
Nothing is due to go out this week.
Harvest soon
37 crops- Basil
- Borage
- Bush Bean
- Cantaloupe
- Cleome (Spider Flower)
- Cosmos
- Cowpea (Black-Eyed Pea)
- Cucumber
- Edamame
- Fennel
- Flour Corn
- French Marigold
- Garden Verbena
- Garlic
- Gourd (Ornamental/Bottle)
- Honeydew Melon
- Lima Bean
- Loofah (Luffa)
- Malabar Spinach
- Nasturtium
- Okra
- Pole Bean
- Pumpkin
- Roselle (Cranberry Hibiscus)
- Scarlet Runner Bean
- Shiso (Japanese Basil)
- Summer Savory
- Sunflower
- Sweet Corn
- Sweet Potato
- Thai Basil
- Vinca (Madagascar Periwinkle)
- Watermelon
- Winter Squash
- Yellow Summer Squash
- Zinnia
- Zucchini
Seasonal tips
- Start succession sowing with Pole Beans or Peas every two weeks for a continuous supply of fresh pods.
- Pinch back the tops of Basil to encourage bushier growth before the heat sets in.
- Apply a light layer of compost around harvested crops to replenish soil nutrients.
Pest & disease watch
- Watch for early season aphids colonizing new growth on emerging basil, borage, and sunflower plants as temperatures rise above 50°F.
- Monitor squash vine borers on newly planted yellow summer squash and zucchini, especially if soil was worked while still wet from recent rains.
- Check for flea beetle damage on germinating bush beans and pole beans, which can occur quickly in the damp microclimates found between city buildings.
Watering this week
Provide about 1 to 2 inches of water per week, ensuring deep watering during hot afternoons.
Harvest Basil in the morning when essential oils are most concentrated for peak flavor.
Philadelphia gardening questions
3When is it safe to plant my bush beans and zucchini directly outside in Philadelphia?
You should wait until after the average last frost date of March 28 before sowing these warm-season crops directly into the ground. Planting earlier can result in seed rot or stunted growth if a late chill occurs.
Can I transplant my basil and borage now, or should they stay indoors?
Basil, borage, and other listed harvestable plants like sweet corn are best started indoors early; do not attempt to transplant them into cold Philadelphia soil yet. Instead, focus on sowing seeds of bush beans and squash that tolerate cooler soil temperatures better.
How does the clay soil in my North or West Philly garden affect planting time for summer squashes?
Philadelphia's notorious clay soil stays cold longer than sandy areas, so ensure the ground has warmed significantly before digging in your yellow summer squash seeds. Wait for a few days of consistently above-freezing weather after March 28 to guarantee good germination.
Other cities in zone 7b
12See the full zone 7b guide → · Plan your Philadelphia garden in SproutGuide →