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When to Plant Alliums in Hardeman County, TN

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.

Hardeman County, Tennessee is in USDA Zone 7b. The average last spring frost is March 30 and the first fall frost is October 30, giving you a growing season of approximately 214 days.

At an elevation of 3,185 feet, Hardeman County receives approximately 48.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92°F, providing good warmth for Alliums during the growing season.

Bulb Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Hardeman County, TN (Zone 7b) Long season
214 days
Last Spring Frost March 30
214 growing days
First Fall Frost October 30

Hardeman County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.5

Drainage

Well Drained

Monthly Watering Guide for Alliums

Alliums needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Alliums Needs Rainfall You Supplement Action
Jan 3.5" 0" ❄️ Dormant
Feb 4.1" 0" ❄️ Dormant
Mar 4.3" 5.2" 0" ✅ Rainfall sufficient
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 3.7" 0.6" 💧 Light watering
Jul 4.3" 5" 0" ✅ Rainfall sufficient
Aug 4.3" 4.6" 0" ✅ Rainfall sufficient
Sep 4.3" 4.1" 0.2" 💧 Light watering
Oct 4.3" 3" 1.3" 💧 Light watering
Nov 3.7" 0" ❄️ Dormant
Dec 4.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Oct in Hardeman County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Alliums Planting Timeline — Hardeman County, TN

Alliums Planting Calendar

Activity When Date Range
Bloom October 23 Oct 23 – Nov 13
Fall Sowing September 25 Sep 25 – Oct 9

Plant 5" deep · 7" apart · Rows 8" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June
July
August
September Fall Sowing
October Fall Sowing 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 7b

📆 Growing Season

214 days in Hardeman County

Growing Tips for Hardeman 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

  • Beans
  • Peas

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Alliums in Hardeman County, TN?

Hardeman County is in Zone 7b with an average last frost of March 30. Plan your Alliums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hardeman County, TN?

Hardeman County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is March 30 and first fall frost is October 30.

🌱

Your Hardeman County Garden Planner — Free

A 22-page printable planner built for Hardeman County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Hardeman County, TN. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.