What to plant this week in St. Louis, MO
With the average last frost date passing on April 3, St. Louis gardeners are officially in the swing of spring planting and early summer harvests across our Zone 7a landscape. This week marks a critical transition where you must focus your energy on harvesting rapidly maturing crops like basil, bush beans, and cucumbers before any unexpected chill returns.
The next 7 days
St. Louis, MOGrowing in St. Louis right now
- Our clay-heavy soils in the Metro East area can become slick when wet; work them only when crumbly to prevent compaction for your new zinnia and cosmos seedlings.
- The humid spring air often stalls growth; ensure full sun exposure for your okra, summer squash, and edamame to encourage blooming over leafy stretching.
- Take advantage of the mild weather to transplant garlic now while it's dormant, or sow frost-tender seeds like basil and shiso directly into warm spots near your home.
- Monitor your sweet potato slips carefully; they are highly susceptible to late spring freezes which can wipe out a season's worth of tubers in just one night.
Sow this week
No direct sowing windows open this week.
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
- Thin out overcrowded seedlings to give remaining plants room for air circulation and sun.
- Apply a light layer of straw mulch around warm-weather crops to retain soil moisture during heat waves.
- Practice succession sowing with fast-maturing beans or radishes every two weeks to extend your harvest window.
Pest & disease watch
- Watch for aphids clustering on the new growth of your pole beans, cosmos, and zinnias as humidity rises through late April.
- Cucumber beetles may start scouting for your cucumbers, pumpkins, and squash; inspect leaves daily and use row covers if infestations appear early.
- Late frosts in low-lying basins along the Mississippi can damage young transplants, so protect sensitive seedlings with row covers until temps stabilize above 50°F.
Watering this week
Water deeply at the base of plants in the early morning to reduce evaporation and prevent fungal diseases on wet foliage.
Harvest basil leaves regularly by pinching off stems just above a leaf pair to encourage bushier growth rather than flowering.
St. Louis gardening questions
3When is the best time to plant my sweet potato slips given our late April freeze risk?
Wait until after May 1 when soil temperatures consistently stay above 60°F, as cold snaps can rot the tubers before sprouts emerge. Keep them in a protected spot or under row covers if a hard freeze is forecasted in early spring.
How do I handle late frosts that might hit our low-lying areas near the river?
Cover sensitive crops like basil, tomatoes, and newly sown zinnias with floating row covers or frost cloths at night to retain heat. Remove them during the day to ensure plants get enough light for photosynthesis.
Are there specific pests I should watch for in St. Louis clay soil this week?
Focus on cucumber beetles and aphids, which thrive in our humid microclimates and can quickly devastate squash and bean harvests. Use yellow sticky traps to monitor beetle populations before they reach damaging levels.
Other cities in zone 7a
12See the full zone 7a guide → · Plan your St. Louis garden in SproutGuide →