What to plant this week in Detroit, MI
With the average last frost date in Detroit hovering around April 21, this week marks your window to push hardy crops like garlic and edamame into the cooler soil before the mid-April warmth settles. You are also ready to start harvesting early-season treasures such as basil, borage, and bush beans that have been tucked away or sprouting indoors.
The next 7 days
Detroit, MIGrowing in Detroit right now
- Detroit's heavy clay soils retain moisture well but drain slowly; break up compacted areas near the riverfront if planting potatoes or sweet corn this week.
- Given your location just west of Lake St. Clair, watch for cooler microclimates in shaded alleyways where frost can linger later than the citywide April 21 average suggests.
- Take advantage of the current harvest list to pull zucchini and summer squash now while they are tender before the intense July heat sets in.
- Since no sow-now crops are listed, focus your energy on hardening off transplants like French marigolds and garden verbena for their peak bloom.
Sow this week
No direct sowing windows open this week.
Transplant this week
Nothing is due to go out this week.
Harvest soon
45 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
- 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
- Vinca (Madagascar Periwinkle)
- Watermelon
- Winter Squash
- Yellow Summer Squash
- Zinnia
- Zucchini
Seasonal tips
- Keep a close eye on pollinator-friendly flowers like Cosmos and Zinnia to ensure good seed set.
- Harvest bush beans and cucumbers frequently to encourage continued production throughout summer.
- Protect young transplants from late spring chill with row covers if an unexpected cold snap occurs.
- Plan succession sowing for cool-season crops now so they are ready as the weather cools in October.
Pest & disease watch
- Spider mites often explode on basil and zucchini during Detroit's humid springs; hose them off early morning to prevent webbing.
- Watch for cutworms attacking young cucumber and melon seedlings in open ground, as this is a prime time for soil-dwelling caterpillars.
- Monitor garlic plants closely for onion thrips, which can weaken bulbs right before the mid-April frost risk passes.
Watering this week
Water deeply in the morning to reduce evaporation and prevent fungal issues on leafy greens.
Save seeds from your best-performing varieties like French Marigold and Zinnia to start your next season's garden early.
Detroit gardening questions
3When should I finally stop worrying about frost damage to my outdoor tomatoes and peppers?
While your average last frost is April 21 in Detroit, it is safer to wait until late May for heat-loving crops like tomatoes to avoid a damaging chill. You can plant them now if you use row covers or cold frames to protect the young stems from any unexpected overnight dips below zero.
My zucchini and summer squash are growing fast this week; how do I tell when they need harvesting?
Harvest your yellow summer squash and zucchini immediately when they are 6 inches long, as letting them grow larger makes the skin tough and reduces yield. Pick them in the morning for the crispest texture before the Detroit afternoon sun begins to heat up the plants.
Is now a good time to plant garlic cloves or should I wait?
This is actually an ideal time to plant garlic if you haven't already, as the soil has warmed enough above freezing but the leaves are still developing slowly before summer growth. Plant cloves 2 inches deep and ensure they get about 4 inches of spacing for your Detroit garden beds.
Other cities in zone 6b
12See the full zone 6b guide → · Plan your Detroit garden in SproutGuide →