Blog

When to plant Alliums in Franklin County, ME

In Zone 5a (Franklin County), direct-sow Alliums between mid-spring and late spring for spring, after the May 14 last-frost mark. A second sowing from August 17 to August 31 extends the harvest into fall.

When to Plant Alliums in Franklin County, ME

Franklin County, Maine Zone 5a June

Your June game plan for Franklin County, Maine

Your garden in Franklin County, Maine is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost May 14
Avg. first frost September 28
Soil temp (4") 63°F
Watering Moderate
Pest pressure High
Daylight 15.4 hrs

Instant PDF download. No spam, unsubscribe any time.

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.

Franklin County, Maine is in USDA Zone 5a. The average last spring frost is May 14 and the first fall frost is September 28, giving you a growing season of approximately 137 days.

At an elevation of 244 feet, Franklin County receives approximately 40.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Alliums to ensure they mature before fall.

Bulb Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Franklin County, ME (Zone 5a) Short season
137 days
Last Spring Frost May 14
137 growing days
First Fall Frost September 28

Franklin County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.6

Drainage

Well Drained

Alliums Planting Risk Windows

Early Start (70% safe) ✓ Fits season (69 days to spare)
Transplant: May 11 🌸 Bloom: Jun 15 – Jul 13
Recommended (50%) ✓ Fits season (74 days to spare)
Transplant: May 14 🌸 Bloom: Jun 18 – Jul 16
Safe Start (90%) ✓ Fits season (70 days to spare)
Transplant: May 31 🌸 Bloom: Jul 5 – Aug 2

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Franklin County

How your county's soil matches Alliums's growing requirements.

Soil pH

Your soil pH (5.2–6.6) overlaps with Alliums's range (5.5–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Franklin County is excellent for Alliums — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.2%). Annual compost additions will help Alliums.

How to Plant Alliums

5"
Planting Depth
7"
Between Plants
8"
Between Rows

Fall planting: Sow 6 weeks before your first frost date for a fall harvest.

Succession Planting Alliums

5
successive plantings in your 137-day season

Sow every 3.1 weeks. Last sowing by Aug 17 to harvest before frost.

For a dedicated fall crop, sow by Aug 17.

Alliums Water Budget

Plant needs
0.5″/week
Rainfall provides
1.3″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Alliums

Alliums needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Alliums Needs Rainfall You Supplement Action
Jan 3.2" 0" ❄️ Dormant
Feb 2.6" 0" ❄️ Dormant
Mar 3.9" 0" ❄️ Dormant
Apr 3.1" 0" ❄️ Dormant
May 2.2" 4.1" 0" ✅ Rainfall sufficient
Jun 2.2" 3.4" 0" ✅ Rainfall sufficient
Jul 2.2" 4.1" 0" ✅ Rainfall sufficient
Aug 2.2" 4.1" 0" ✅ Rainfall sufficient
Sep 2.2" 3" 0" ✅ Rainfall sufficient
Oct 3.4" 0" ❄️ Dormant
Nov 2.7" 0" ❄️ Dormant
Dec 3.2" 0" ❄️ Dormant

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

Alliums Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Alliums needs ~350 GDD — county provides 1,370 GDD Excellent fit

Alliums Planting Timeline — Franklin County, ME

Alliums Planting Calendar

Activity When Date Range
Bloom September 21 Sep 21 – Oct 19
Fall Sowing August 17 Aug 17 – Aug 31

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June
July
August Fall Sowing
September Bloom
October Bloom
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

28–42 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

137 days in Franklin County

Growing Tips for Alliums in Franklin County

Direct sow Alliums outdoors after May 14 in Franklin County when soil has warmed and frost danger has passed.

Your generous 137.0-day season in Franklin County allows multiple plantings of Alliums. Sow every 14.0 days for continuous harvest.

Common pests for Alliums in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

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 Franklin County, ME?

Franklin County is in Zone 5a with an average last frost of May 14. Plan your Alliums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Franklin County, ME?

Franklin County, Maine is in USDA Hardiness Zone 5a. The average last spring frost is May 14 and first fall frost is September 28.

When should I plant Alliums in Franklin County, ME?

In Franklin County, ME, plant Alliums after the last frost (around May 14) and before the first frost (around September 28). Best results when soil holds above 50°F.

What growing zone is Franklin County, ME for Alliums?

Franklin County sits in USDA Zone 5a. Alliums grows reliably in zones 3a through 9b, so it's a good fit here.

Can Alliums grow in Franklin County's climate?

Yes — Alliums grows well in Franklin County's temperate climate. Franklin County averages a 137-day frost-free season, with last frost around May 14 and first frost around September 28.

🌱

Your Franklin County Garden Planner — Free

A 22-page printable planner built for Franklin County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Franklin County, ME. 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.