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When to plant Alliums in Trego County County,

Spring Alliums in Trego County County goes in mid-spring–late spring, once nighttime temps stop dipping near freezing. A second sowing from September 4 to September 18 extends the harvest into fall.

When to Plant Alliums in Trego County, KS

Trego County, Kansas Zone 6a June

Your June gardening checklist

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 21
Avg. first frost October 16
Soil temp (4") 68°F
Watering Low
Pest pressure High
Daylight 14.7 hrs

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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.

Trego County, Kansas is in USDA Zone 6a. The average last spring frost is April 21 and the first fall frost is October 16, giving you a growing season of approximately 178 days.

At an elevation of 618 feet, Trego County receives approximately 30.8 inches of rainfall annually with predominantly loam soil. Summer highs average 84°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
Trego County, KS (Zone 6a) Moderate season
178 days
Last Spring Frost April 21
178 growing days
First Fall Frost October 16
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Trego County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.8

Drainage

Well Drained

Alliums Planting Risk Windows

Early Start (70% safe) ✓ Fits season (121 days to spare)
Transplant: Apr 16 🌸 Bloom: May 14 – Jun 11
Recommended (50%) ✓ Fits season (122 days to spare)
Transplant: Apr 21 🌸 Bloom: May 19 – Jun 16
Safe Start (90%) ✓ Fits season (121 days to spare)
Transplant: May 4 🌸 Bloom: Jun 1 – Jun 29

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 Trego County

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

Soil pH

Your soil pH (6.6–7.8) overlaps with Alliums's range (5.5–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — Alliums will thrive.

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

7
successive plantings in your 178-day season

Sow every 3.1 weeks. Last sowing by Sep 04 to harvest before frost.

For a dedicated fall crop, sow by Sep 04.

Alliums Water Budget

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

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

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 0.9" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.2" 3.2" 0" ✅ Rainfall sufficient
May 2.2" 4.5" 0" ✅ Rainfall sufficient
Jun 2.2" 4.6" 0" ✅ Rainfall sufficient
Jul 2.2" 4.1" 0" ✅ Rainfall sufficient
Aug 2.2" 3.4" 0" ✅ Rainfall sufficient
Sep 2.2" 3.1" 0" ✅ Rainfall sufficient
Oct 2.2" 2" 0.2" 💧 Light watering
Nov 1.2" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Trego 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 ~455 GDD — county provides 2,314 GDD Excellent fit

Alliums Planting Timeline — Trego County, KS

Alliums Planting Calendar

Activity When Date Range
Bloom October 2 Oct 2 – Oct 30
Fall Sowing September 4 Sep 4 – Sep 18

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 Bloom
November
December
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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 6a

📆 Growing Season

178 days in Trego County

Growing Tips for Alliums in Trego County

Direct sow Alliums outdoors after April 21 in Trego County when soil has warmed and frost danger has passed.

Your generous 178.0-day season in Trego 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 Trego County, KS?

Trego County is in Zone 6a with an average last frost of April 21. Plan your Alliums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Trego County, KS?

Trego County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 21 and first fall frost is October 16.

When should I plant Alliums in Trego County County, ?

In Trego County County, , plant Alliums after the last frost (around April 21) and before the first frost (around October 16). Best results when soil holds above 50°F.

What growing zone is Trego County County, for Alliums?

Trego County County sits in USDA Zone 6a. Alliums grows reliably in zones 3a through 9b, so it's a good fit here.

Can Alliums grow in Trego County County's climate?

Yes — Alliums grows well in Trego County County's temperate climate. Trego County County averages a 178-day frost-free season, with last frost around April 21 and first frost around October 16.

🌱

Your Trego County Garden Planner — Free

A 22-page printable planner built for Trego County (Zone 6a). 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 Trego County, KS. Local conditions may vary. Last updated: June 2026.

Sources & credits

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