When to Plant Alliums in Highland County, OH
Ornamental alliums (Allium spp.) bridge the gap between spring and summer with their striking globe-shaped flower heads in shades of purple, violet, white, and pink. Blooming after tulips have faded, they extend the spring display well into early summer. 'Gladiator', 'Globemaster', and 'Purple Sensation' produce softball-sized heads on 18–36 inch stems, while smaller species create charming accents at border fronts. Deer and rodents shun them completely due to the characteristic onion scent. Dried seed heads provide architectural interest into fall.
Highland County, Ohio is in USDA Zone 6b. The average last spring frost is April 22 and the first fall frost is October 21, giving you a growing season of approximately 182 days.
At an elevation of 556 feet, Highland County receives approximately 33.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Alliums during the growing season.
Highland County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Alliums Planting Timeline — Highland County, OH
Alliums Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Bloom | October 7 | Oct 7 – Nov 4 |
| Fall Sowing | September 9 | Sep 9 – Sep 23 |
Plant 5" deep · 7" apart · Rows 8" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | — |
| July | — |
| August | — |
| September | Fall Sowing |
| October | Bloom |
| November | Bloom |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Low — drought tolerant
📅 Days to Maturity
28–42 days
🧪 Soil pH
Needs 5.5–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 6b
📆 Growing Season
182 days in Highland County
Growing Tips for Highland County
Plant bulbs in fall, 3–4 times as deep as the bulb diameter (typically 4–6 inches for large types, 3 inches for small species). Space 6–8 inches apart for standard cultivars. Foliage often looks untidy as it dies back before bloom — plant around perennials that will conceal the yellowing leaves. Excellent drainage is essential; alliums rot in wet soils. Leave bulbs in place for naturalization; divide every 3–4 years when clusters become congested. Deadhead spent globes or leave for ornamental seedheads and self-sowing.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Alliums in Other Locations
Frequently Asked Questions
When should I plant Alliums in Highland County, OH?
Highland County is in Zone 6b with an average last frost of April 22. Plan your Alliums planting based on this frost date — see the calendar above for exact timing.
What planting zone is Highland County, OH?
Highland County, Ohio is in USDA Hardiness Zone 6b. The average last spring frost is April 22 and first fall frost is October 21.
Your Highland County Garden Planner — Free
A 22-page printable planner built for Highland County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.