What to plant this week in Washington, DC
In Washington, DC's humid capital garden, this week marks the peak of mid-summer heat and moisture where you can aggressively harvest your summer crops like cucumbers and okra while sowing heat-loving annuals such as cosmos and zinnia. With frost dates firmly in the past until late November, focus on protecting root systems from DC's notorious clay-heavy soils and managing the high humidity that fuels fungal issues.
The next 7 days
Washington, DCGrowing in Washington right now
- DC soil is notoriously heavy clay with poor drainage; amend raised beds with compost and avoid planting directly into wet ground to prevent rot in squash and melons.
- The region receives significant afternoon thunderstorms this time of year; use drip irrigation early morning to keep foliage dry and reduce the spread of powdery mildew on beans and leafy greens.
- Urban heat islands in DC often push temperatures higher than surrounding suburbs, making it an ideal window to sow late-maturing crops like watermelon that might struggle earlier in the season.
Sow this week
30 crops- Basil
- Borage
- Bush Bean
- Cantaloupe
- Cleome (Spider Flower)
- Cosmos
- Cowpea (Black-Eyed Pea)
- Cucumber
- Edamame
- Fennel
- French Marigold
- Garden Verbena
- Honeydew Melon
- Lima Bean
- Malabar Spinach
- Nasturtium
- Okra
- Pole Bean
- Scarlet Runner Bean
- Shiso (Japanese Basil)
- Summer Savory
- Sunflower
- Sweet Corn
- Thai Basil
- Vinca (Madagascar Periwinkle)
- Watermelon
- Winter Squash
- Yellow Summer Squash
- Zinnia
- Zucchini
Transplant this week
Nothing is due to go out this week.
Harvest soon
41 crops- Basil
- Borage
- 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)
- Honeydew Melon
- Lima Bean
- Lisianthus (Prairie Gentian)
- 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
- Succession sow bush beans and pole beans every two weeks for a continuous harvest throughout the summer.
- Apply a light layer of mulch around warm-season vegetables to retain soil moisture and keep roots cool.
- Pinch back the tops of basil plants regularly to encourage bushier growth before harvesting leaves.
Pest & disease watch
- Spiders (Ghost Pepper) are notorious in DC backyards this month; monitor plants closely as they can quickly defoliate squash and beans if left unchecked.
- Powdery mildew thrives in our humid, stagnant air pockets; prune for airflow and apply preventive treatments on susceptible varieties like fennel and okra immediately upon seeing white spots.
Watering this week
Water deeply in the morning to keep moisture consistent but avoid wetting the foliage to prevent disease.
Harvest beans when pods are young and tender to maximize flavor and encourage further production from each plant.
Washington gardening questions
3Can I plant winter squash now, or should I wait until the summer heat breaks?
You can absolutely sow winter squash now in DC's zone 8a climate because the long growing season allows them to mature before our November frost date. Just be sure to space plants widely for air circulation given the humid conditions that encourage disease.
Is it safe to transplant seedlings now, or should everything be direct seeded?
Pinch off any flower buds immediately to redirect energy back to leaf production, and switch to planting heat-tolerant varieties like Thai or Shiso basil which thrive in our DC summers.
Should I harvest my garlic before the ground freezes solid next week?
No need to worry about immediate frost damage; you can wait until mid-November when leaves have yellowed naturally, as our first average frost doesn't occur until late November.
Other cities in zone 8a
11See the full zone 8a guide → · Plan your Washington garden in SproutGuide →