Now
25°C · Clear
Today
25° / 17°
Soil 6 cm
21°C
First frost
~50 days (Oct 28)
Gardening in Milwaukee
AI field guide · refreshed weeklyMilwaukee Gardening: September 8–14, 2026
Zone 5b means your average first fall frost arrives October 28—you have 50 days left. Soil at 22°C is still warm enough for cool-season crops to germinate and establish quickly. Spring frost averaged May 1, so you're 130 days into the growing season. Expect frost to end most tender plants by late October; plan accordingly.
Sow outdoors now
Spinach (Bloomsdale, Space or Tyee)
Sow directly 1 cm deep, 10 cm apart. Germinates in 7–10 days at soil temp 22°C; matures in 40–50 days before hard frost.
Arugula (Roquette)
Scatter seed 0.5 cm deep, thin to 15 cm. Ready to cut in 30 days; successive sowings every 2 weeks until mid-September.
Radish (Cherry Belle, French Breakfast)
Sow 1 cm deep, 5 cm apart. Matures in 25–30 days; excellent for quick succession planting.
Mâche (Corn Salad)
Sow 0.5 cm deep in rows 20 cm apart. Slow to germinate (14–21 days) but cold-hardy; overwinters in zone 5b for spring harvest.
Turnip (Purple Top, Hakurei)
Sow 1 cm deep, thin to 10 cm. Roots ready in 50–60 days; greens edible in 30 days.
Start indoors now
Kale (Lacinato, Winterbor)
Start seed indoors in trays; transplant in 4–5 weeks (early October). Cold-hardy varieties sweeten after frost.
Cabbage (January King, Savoy)
Start seed now for transplant in 5 weeks; harvest before hard freeze or store in cool cellar.
Broccoli (Calabrese, De Cicco)
Start indoors; transplant mid-October for November harvest before first hard frost.
Harvest now
Tomatoes (all varieties)
Pick ripe fruit now; pull entire plants by late September and ripen indoors or make green tomato relish.
Beans (bush and pole)
Harvest pods regularly to encourage final flushes; frost will kill plants by late October.
Squash and Zucchini
Cut mature fruit with 2–3 cm stem; cure in warm, dry place for storage. Frost will end production within 6 weeks.
Peppers (sweet and hot)
Pick ripe peppers now; immature fruit will ripen indoors if plants are pulled before frost.
Tasks this week
- Deadhead spent flowers to extend bloom on ornamentals; cut back perennials after frost.
- Divide spring-blooming perennials (daylilies, hostas, coneflowers) this week through October.
- Plant spring bulbs (tulips, daffodils, crocus) now through October; soil temp 22°C is ideal for root development.
- Clean up fallen leaves and debris to reduce overwintering pests and disease; compost disease-free material.
- Stop fertilizing trees, shrubs, and perennials to harden off growth before hard frost.
Watch out for
- Powdery mildew and early blight thrive in cool, humid conditions (87% humidity today)—improve air flow and remove affected foliage.
- Japanese beetles and grasshoppers are still active; handpick or use row covers on young greens.
- Frost can arrive earlier than October 28 in low-lying areas; monitor forecasts and cover tender plants on cold nights.
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