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When to Plant Daylily in Park County, WY

Park County, Wyoming Zone 5a June

Your June gardening checklist

Each item below is timed to Park County, Wyoming's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 21
Avg. first frost September 22
Soil temp (4") 44°F
Watering Critical
Pest pressure High
Daylight 15.3 hrs
  1. Move daylily into the garden

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

To set up a strong July, finish these tasks
  • Starting indoors: daylily

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Hemerocallis (Daylily) is one of the most adaptable and trouble-free perennials in cultivation. Though each flower lasts only a single day, established clumps produce dozens to hundreds of buds per stem, delivering weeks of continuous color through summer. Modern hybrids extend the range from pale cream and melon through deep burgundy and purple. Nearly indestructible once established — tolerating poor soil, drought, competition, and neglect — daylilies form dense spreading clumps that effectively suppress weeds. An excellent low-maintenance choice for slopes, borders, and naturalized areas.

Park County, Wyoming is in USDA Zone 5a. The average last spring frost is May 21 and the first fall frost is September 22, giving you a growing season of approximately 124 days.

At an elevation of 6,993 feet, Park County receives approximately 16.7 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Daylily to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Daylily successfully. Mulch heavily to conserve soil moisture.

Perennial Blooms in Summer Pollinator-friendly Good for cutting
Park County, WY (Zone 5a) Short season
124 days
Last Spring Frost May 21
124 growing days
First Fall Frost September 22

Park County Soil Profile

Soil Type

Loam

Soil pH

6.8-8.2

Drainage

Well Drained

Daylily Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 8 Transplant: May 24 🌸 Bloom: Aug 16 – Nov 8
Recommended (50%) ✗ May not fit
Start indoors: Mar 19 Transplant: Jun 4 🌸 Bloom: Aug 27 – Nov 19
Safe Start (90%) ✗ May not fit
Start indoors: Apr 26 Transplant: Jul 12 🌸 Bloom: Oct 4 – Dec 27

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 Park County

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

Soil pH

Your soil pH (6.8–8.2) is more alkaline than Daylily prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Daylily.

How to Plant Daylily

1"
Planting Depth
24"
Between Plants
30"
Between Rows

Succession Planting Daylily

2
successive plantings in your 124-day season

Sow every 6.9 weeks. Last sowing by Jun 24 to harvest before frost.

Daylily Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/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 Daylily

Daylily 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 Daylily Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 1.8" 0" ❄️ Dormant
May 2.2" 2.1" 0.1" 💧 Light watering
Jun 2.2" 1.2" 1" 💧 Light watering
Jul 2.2" 1.5" 0.7" 💧 Light watering
Aug 2.2" 1.7" 0.5" 💧 Light watering
Sep 2.2" 1.2" 1" 💧 Light watering
Oct 1.4" 0" ❄️ Dormant
Nov 1.3" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

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

Daylily 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.

Daylily needs ~919 GDD — county provides 1,519 GDD Excellent fit

Daylily Planting Timeline — Park County, WY

Daylily Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 – Apr 2
Transplant Outdoors June 4 Jun 4 – Jun 18
Bloom August 27 Aug 27 – Nov 19

Plant 1" deep · 24" apart · Rows 30" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

124 days in Park County

Growing Tips for Daylily in Park County

Direct sow Daylily outdoors after May 21 in Park County when soil has warmed and frost danger has passed.

Park County receives only 17" of rain annually. Daylily needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Daylilies are most commonly propagated by division rather than seed; cultivar seeds do not come true. Transplant bare-root or potted divisions in early spring or fall, setting crowns no more than 1 inch below soil level. If starting from seed (species types only), start indoors 8–10 weeks before last frost. Established plants are extremely drought-tolerant; moderate water during bloom period improves flower quality. Divide crowded clumps every 3–5 years in early spring or fall to maintain vigor. In warm zones (8+), some cultivars are evergreen; in cold zones, foliage dies back each fall. Year 2+ plants bloom most heavily — first-year transplants may produce limited flowers.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Daylily in Park County, WY?

Park County is in Zone 5a with an average last frost of May 21. Plan your Daylily planting based on this frost date — see the calendar above for exact timing.

What planting zone is Park County, WY?

Park County, Wyoming is in USDA Hardiness Zone 5a. The average last spring frost is May 21 and first fall frost is September 22.

🌱

Your Park County Garden Planner — Free

A 22-page printable planner built for Park 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.

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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 Park County, WY. 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.