When to Plant Geraniums in Adams County, WI
Geraniums (Pelargonium × hortorum) are tender perennials grown as warm-season annuals throughout North America. Prized for their bold flower clusters, long bloom period, and tolerance of summer heat when planted in well-drained soil, they anchor window boxes, containers, and bed borders from late spring until hard frost. Zones 9b–11b can overwinter plants in the ground.
Adams County, Wisconsin is in USDA Zone 4b. The average last spring frost is May 6 and the first fall frost is October 5, giving you a growing season of approximately 152 days.
At an elevation of 1,055 feet, Adams County receives approximately 41.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Geraniums to ensure they mature before fall.
Adams County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Geraniums Planting Timeline — Adams County, WI
Geraniums Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 18 | Feb 18 – Mar 4 |
| Transplant Outdoors | May 13 | May 13 – May 27 |
| Bloom | July 22 | Jul 22 – Sep 30 |
Plant 0.1" deep · 12" apart · Rows 14" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 4b
📆 Growing Season
152 days in Adams County
Growing Tips for Adams County
Start seeds indoors 10–12 weeks before last frost — germination is slow and erratic without bottom heat (70–75°F). Transplant after frost danger passes. Geraniums rarely direct-sown; cuttings or transplants are the standard. Deadhead spent umbels weekly to maintain continuous bloom. Let soil dry slightly between waterings to prevent root rot. In zones 10–11 plants may be left in ground year-round or overwintered as houseplants.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Geraniums in Other Locations
Frequently Asked Questions
When should I plant Geraniums in Adams County, WI?
Adams County is in Zone 4b with an average last frost of May 6. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.
What planting zone is Adams County, WI?
Adams County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is May 6 and first fall frost is October 5.
Your Adams County Garden Planner — Free
A 22-page printable planner built for Adams County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.