What to plant this week in Philadelphia, PA
Philadelphia gardeners in zone 7b can finally push forward with warm-season crops this week as the risk of a late freeze on March 28th fades. With temperatures hovering near our historical minimum of 5°F, now is the perfect time to sow squash and zucchini directly into your beds.
The next 7 days
Philadelphia, PAGrowing in Philadelphia right now
- Philadelphia's clay-heavy soils in older neighborhoods often stay cold longer; wait until the soil feels warm enough before sowing yellow summer squash or zucchini to ensure germination.
- Our typical April rainfall can be heavy, so mulch transplants like basil and borage immediately after setting them out to protect roots from puddling on our compacted urban lawns.
- Be aware that our city heat island effect might push your harvest dates for cucumbers and okra a week earlier than the countryside counterparts in this zone.
Sow this week
2 crops- Yellow Summer Squash
- Zucchini
Transplant this week
Nothing is due to go out this week.
Harvest soon
36 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
- Thai Basil
- Vinca (Madagascar Periwinkle)
- Watermelon
- Winter Squash
- Yellow Summer Squash
- Zinnia
- Zucchini
Seasonal tips
- Succession sow bush beans every two weeks to ensure a continuous harvest through late August.
- Thin seedlings early on okra and watermelon plants to allow remaining specimens room to spread their vines.
- Apply a light layer of compost around established summer squash and zucchini to feed heavy fruiting plants.
Pest & disease watch
- Watch for early aphid colonies forming on newly sprouted beans and sunflowers as we move past the last frost date of March 28th.
- Slugs and snails are particularly active during our frequent spring rains, targeting young tomato plants if you transplant any late varieties now.
- Spider mites can appear quickly in the heat pockets of city parks, so check undersides of leaves on zinnias and cosmos regularly.
Watering this week
Water deeply in the early morning to keep soil moist without wetting foliage, especially when fruit sets in.
Harvest zucchini and summer squash every two days to prevent them from becoming tough and bitter.
Philadelphia gardening questions
3Is it safe to plant my zucchini seeds now that we are past the last frost?
Yes, with an average last frost date of March 28th, you can safely sow yellow summer squash and zucchini directly in the ground this week. Just ensure your soil has warmed up sufficiently since Philadelphia clay retains moisture longer than sand.
When should I expect to start harvesting my basil and bush beans?
Basil planted now will likely be ready for harvest soon, while bush beans typically take a few weeks after emergence to mature. Keep an eye on them as our short growing season moves toward the first frost in mid-November.
How do I protect my summer squash from our typical heavy spring rains?
Since we often get significant rainfall this time of year, create small mounds or raised beds for your squash to prevent root rot. Adding a layer of straw mulch will also help regulate soil temperature and keep water from pooling around the base.
Other cities in zone 7b
12See the full zone 7b guide → · Plan your Philadelphia garden in SproutGuide →