What to plant this week in Wilmington, DE
In Wilmington this week, the lingering threat of a late frost before March 28 means you must wait to move tender starts outside until the soil warms up, even though the air feels pleasant. However, this is prime time to sow warm-season giants like Bush Beans and Sweet Corn that will thrive in our humid coastal lowlands once the ground temperature rises.
The next 7 days
Wilmington, DEGrowing in Wilmington right now
- Our sandy-loam mix along the Delaware River drains fast but dries out quickly, so water newly sown beans and corn deeply every two days rather than lightly daily. Avoid planting edibles in the immediate flood zones near the waterfront unless you elevate the bed by a foot to protect roots from spring tides.
- Delay transplanting anything until after March 28; instead, direct sow heat-lovers like Okra and Malabar Spinach right now since they struggle if moved before their roots are established.
- The coastal humidity accelerates fungal issues in heavy clay pockets found on older estates inland, so ensure your raised beds have excellent air circulation to prevent blight.
Sow this week
27 crops- Basil
- Borage
- Bush Bean
- Cantaloupe
- Cleome (Spider Flower)
- Cosmos
- Cowpea (Black-Eyed Pea)
- Cucumber
- Edamame
- Fennel
- French Marigold
- Garden Verbena
- Lima Bean
- Malabar Spinach
- Nasturtium
- Okra
- Pole Bean
- Scarlet Runner Bean
- Shiso (Japanese Basil)
- Summer Savory
- Sweet Corn
- Thai Basil
- Vinca (Madagascar Periwinkle)
- Watermelon
- Yellow Summer Squash
- Zinnia
- Zucchini
Transplant this week
Nothing is due to go out this week.
Harvest soon
48 crops- Basil
- Borage
- Brussels Sprouts
- Bush Bean
- Cantaloupe
- Celery
- Cleome (Spider Flower)
- Cosmos
- Cowpea (Black-Eyed Pea)
- Cucumber
- Dahlia
- Edamame
- Fennel
- Flour Corn
- French Marigold
- Garden Verbena
- Garlic
- Ghost Pepper (Bhut Jolokia)
- Gourd (Ornamental/Bottle)
- Habanero Pepper
- Honeydew Melon
- Leek
- Lima Bean
- Lisianthus (Prairie Gentian)
- Loofah (Luffa)
- Malabar Spinach
- Nasturtium
- Okra
- Ornamental Sweet Potato Vine
- Parsnip
- Pole Bean
- Potato
- Pumpkin
- Roselle (Cranberry Hibiscus)
- Scarlet Runner Bean
- Shiso (Japanese Basil)
- Summer Savory
- Sunflower
- Sweet Corn
- Sweet Potato
- Thai Basil
- Tomatillo
- Vinca (Madagascar Periwinkle)
- Watermelon
- Winter Squash
- Yellow Summer Squash
- Zinnia
- Zucchini
Seasonal tips
- Succession sow bush beans and pole beans every two weeks to extend your summer bean harvest.
- Apply a light mulch around newly transplanted squash and watermelons to retain soil moisture as temperatures rise.
- Pinch back the tops of basil plants regularly now that they are established to encourage bushier growth.
- Prepare for a second planting of fast-maturing crops like radishes or lettuce if you missed an earlier window.
Pest & disease watch
- Spider Mites: The rising temperatures and humidity make these tiny pests a top threat for Zinnias and Garden Verbena; spray with insecticidal soap early before they web the foliage.
- Cutworms: Keep an eye on young Bean and Corn seedlings at night when adults lay eggs, using cardboard collars to protect emerging stems from this local ground pest.
- Late Blight: Monitor your Potato and Tomato families closely for dark lesions on leaves as our damp springs create ideal conditions for rapid spread.
Watering this week
Water deeply at the base of plants each morning to encourage deep roots while preventing fungal diseases on foliage.
Harvest your okra early in the morning when pods are tender, as they become tough and stringy later in the day.
Wilmington gardening questions
3Can I plant my Summer Squash starts now in Wilmington?
No, you should wait until after the average last frost date of March 28 to transplant squashes, as cold winds from the coast can shock their roots and stunt growth. It is safer to direct sow seeds into warm soil right now if you want them growing immediately.
What vegetables grow best in our sandy coastal soil here?
Bush Beans, Sweet Corn, and Zucchini perform exceptionally well because they tolerate the fast-draining nature of our local loam better than heavy-rooted crops like lettuce. Add compost to your beds before planting to boost nutrient retention for these warm-season favorites.
When should I harvest my early Bush Beans planted last week?
You can expect to start snapping those tender pods in about 50 to 60 days, provided you keep the soil consistently moist during this dry spell. Pinch off the first few flower clusters if the plant has too many blossoms at once to encourage heavier pod production.
Other cities in zone 7b
12See the full zone 7b guide → · Plan your Wilmington garden in SproutGuide →