What to plant this week in Chicago, IL
With average last frost just a few weeks away on April 21, Chicago gardeners are transitioning from late spring prep to early summer sowing for zone 6b. This week marks the ideal window to start cold-hardy crops like peas and lettuce indoors while preparing heavy clay beds for warm-weather transplants arriving soon.
The next 7 days
Chicago, ILGrowing in Chicago right now
- Chicago's signature heavy clay soil dries out slowly in May; avoid deep tilling when wet to prevent compaction and instead focus on surface mulching to regulate temperature.
- The city's high humidity creates a microclimate that accelerates fungal growth; ensure your south-side gardens have maximum airflow between rows of squash and beans.
- Wind tunnels formed by the urban canyon effect can snap tall zinnias and sunflowers; stake plants early or interplant with shorter, sturdy crops like marigolds for protection.
- Expect erratic rainfall patterns typical of the South Side versus the North Shore; check drainage before planting okra in low-lying areas prone to winter snowmelt pooling.
Sow this week
17 crops- Basil
- Borage
- Bush Bean
- Cleome (Spider Flower)
- Cucumber
- French Marigold
- Malabar Spinach
- Nasturtium
- Okra
- Pole Bean
- Scarlet Runner Bean
- Summer Savory
- Thai Basil
- Vinca (Madagascar Periwinkle)
- Yellow Summer Squash
- Zinnia
- Zucchini
Transplant this week
Nothing is due to go out this week.
Harvest soon
58 crops- Anaheim (New Mexico) Pepper
- Banana Pepper
- Basil
- Beefsteak Tomato
- Beet
- Bell Pepper
- Borage
- Brussels Sprouts
- Bush Bean
- Cantaloupe
- Carrot
- Cayenne Pepper
- Cleome (Spider Flower)
- Cosmos
- Cowpea (Black-Eyed Pea)
- Cucumber
- Dahlia
- Edamame
- Eggplant
- Fennel
- Flour Corn
- French Marigold
- Garden Geranium (Zonal)
- Garden Verbena
- Garlic
- Honeydew Melon
- Jalapeño
- Lantana
- Lima Bean
- Malabar Spinach
- Marconi Pepper
- Nasturtium
- Okra
- Ornamental Sweet Potato Vine
- Parsley
- Parsnip
- Petunia
- Poblano Pepper
- Pole Bean
- Potato
- Roma Tomato
- Rutabaga
- Scallion (Bunching Onion)
- Scarlet Runner Bean
- Serrano Pepper
- Shiso (Japanese Basil)
- Snapdragon
- Summer Savory
- Sunflower
- Sweet Corn
- Thai Basil
- Tomatillo
- Tomato
- Vinca (Madagascar Periwinkle)
- Watermelon
- Yellow Summer Squash
- Zinnia
- Zucchini
Seasonal tips
- Succession sow bush beans and pole beans every two weeks for a continuous harvest throughout the summer.
- Mulch around young tomato and pepper plants to retain soil moisture as temperatures rise above 80°F.
- Thin carrot and beet seedlings now to prevent overcrowding and ensure sturdy root development.
Pest & disease watch
- Aphid populations are exploding on newly emerging bean leaves and tomato foliage due to rising temperatures and humidity; spray with insecticidal soap every 3 days if infestations appear.
- Late-season blight is starting to threaten early-planted tomatoes in the wet conditions common after April showers; practice leaf wiping and water only at dawn.
- Cutworms are actively hiding in mulch and emerging to attack the stems of young squash and pepper seedlings; check soil surfaces nightly or use paper collars.
Watering this week
Water deeply in the early morning to encourage deep root growth and reduce evaporation losses during this hot season.
Harvest sweet corn when the kernels are milky and firm, not yet hard or fully browned, for peak sweetness.
Chicago gardening questions
3When can I finally move my tomato seedlings outside in Chicago?
Wait until after April 21 when the last frost risk passes, but only bring them out on days where overnight lows stay above 50°F. Since Chicago zones often see sudden cold snaps, harden off seedlings gradually for a week before placing them in your raised beds or heavy clay plots.
My squash plants are wilting despite the recent rain; is this normal for Chicago soil?
In our local clay-heavy ground, roots can struggle to breathe if water pools overnight after the April showers. Check that your planting site isn't a low spot where snowmelt collects and aerate the soil gently with a pitchfork before watering again.
Can I harvest my early potatoes now in mid-April?
Not yet; while some scallions and parsnips might be ready soon, Chicago's cool springs mean main crop potatoes need until late May to mature fully. Focus your harvesting efforts this week on hardy greens like parsley and beet tops that are already listed for immediate pick.
Other cities in zone 6b
12See the full zone 6b guide → · Plan your Chicago garden in SproutGuide →