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When to Plant Lilies in Harmon County, OK

Harmon County, Oklahoma Zone 7b June

What to do in June

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

Avg. last frost March 31
Avg. first frost November 5
Soil temp (4") 76°F
Watering Low
Pest pressure High
Daylight 14.3 hrs
  1. Basket week: lilies

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Looking ahead to July
  • First harvests: lilies

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Lilies (Lilium spp.) are among the most impressive summer-blooming bulbs, delivering bold, upward- or outward-facing trumpet blooms on tall stems from June through August. Asiatic hybrids are the most cold-hardy, earliest to bloom, and easiest to grow; Oriental hybrids bloom later with intensely fragrant, larger flowers. Orienpet (OT) hybrids combine the hardiness of Asiatics with the fragrance and size of Orientals. True lilies (not to be confused with daylilies, which are Hemerocallis) form scaly bulbs that persist and multiply underground, returning reliably each year with increasingly large clumps.

Harmon County, Oklahoma is in USDA Zone 7b. The average last spring frost is March 31 and the first fall frost is November 5, giving you a growing season of approximately 219 days.

At an elevation of 993 feet, Harmon County receives approximately 34.4 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Lilies during the growing season.

Perennial Blooms in Summer Pollinator-friendly Good for cutting Fragrant
Harmon County, OK (Zone 7b) Long season
219 days
Last Spring Frost March 31
219 growing days
First Fall Frost November 5

Harmon County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.5

Drainage

Well Drained

Lilies Planting Risk Windows

Early Start (70% safe) ✓ Fits season (37 days to spare)
Transplant: Mar 23 🌸 Bloom: Jun 1 – Sep 21
Recommended (50%) ✓ Fits season (37 days to spare)
Transplant: Mar 31 🌸 Bloom: Jun 9 – Sep 29
Safe Start (90%) ✓ Fits season (37 days to spare)
Transplant: Apr 15 🌸 Bloom: Jun 24 – Oct 14

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 Harmon County

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

Soil pH

Your soil pH (6.5–7.5) is more alkaline than Lilies prefers (6.0–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.0%) — Lilies will thrive.

How to Plant Lilies

5"
Planting Depth
12"
Between Plants
18"
Between Rows

Succession Planting Lilies

3
successive plantings in your 219-day season

Sow every 8 weeks. Last sowing by Jul 08 to harvest before frost.

Lilies Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 796 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Lilies

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

Month Lilies Needs Rainfall You Supplement Action
Jan 0.9" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 4.3" 2.3" 2" 💧 Light watering
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 5.1" 0" ✅ Rainfall sufficient
Jun 4.3" 5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 4.8" 0" ✅ Rainfall sufficient
Sep 4.3" 3" 1.3" 💧 Light watering
Oct 4.3" 2" 2.3" 🚿 Regular watering
Nov 4.3" 1.3" 3" 🚿 Regular watering
Dec 1" 0" ❄️ Dormant

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

Lilies 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.

Lilies needs ~1,734 GDD — county provides 3,996 GDD Excellent fit

Lilies Planting Timeline — Harmon County, OK

Lilies Planting Calendar

Activity When Date Range
Transplant Outdoors March 31 Mar 31 – Apr 14
Bloom June 9 Jun 9 – Sep 29

Plant 5" deep · 12" apart · Rows 18" apart

Month-by-Month Timeline

MonthActivities
January
February
March Transplant Outdoors
April Transplant Outdoors
May
June Bloom
July Bloom
August Bloom
September Bloom
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

70–120 days

🧪 Soil pH

Needs 6–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7b

📆 Growing Season

219 days in Harmon County

Growing Tips for Lilies in Harmon County

Direct sow Lilies outdoors after March 31 in Harmon County when soil has warmed and frost danger has passed.

General growing tips

Plant bulbs in fall (preferred, September–October) or spring, setting them 3 times their diameter deep (typically 4–6 inches) with the pointed end up. Lilies need excellent drainage — they will rot in wet or heavy clay soils. Site with full sun on stems and blooms but cool, shaded soil at the base (ground cover or shallow-rooted annuals at their feet is ideal). Remove spent blooms but leave stems and foliage until they yellow naturally, as the bulb needs the foliage to photosynthesize and rebuild energy stores. Red lily beetle is a serious pest in the Northeast and Pacific Northwest; inspect plants regularly and hand-pick adults and larvae. Never plant Oriental or Asiatic lilies near cats — all Lilium species are highly toxic to cats. Year 2+ bulbs produce the most stems and largest blooms.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lilies in Harmon County, OK?

Harmon County is in Zone 7b with an average last frost of March 31. Plan your Lilies planting based on this frost date — see the calendar above for exact timing.

What planting zone is Harmon County, OK?

Harmon County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is March 31 and first fall frost is November 5.

🌱

Your Harmon County Garden Planner — Free

A 22-page printable planner built for Harmon 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 Harmon County, OK. 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.