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When to plant Daylily in Washington County County,

Washington County County's 148-day season only supports one Daylily planting per year. Sow between May 24 and June 7 for the best chance at full maturity before October 5.

When to Plant Daylily in Washington County, CO

Washington County, Colorado Zone 5b June

Top priorities for Washington County, Colorado gardeners in June

We've pulled the most time-sensitive tasks for Washington County, Colorado this June and put them front and centre. Tackle them in order.

Avg. last frost May 10
Avg. first frost October 5
Soil temp (4") 53°F
Watering Critical
Pest pressure High
Daylight 14.8 hrs
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.

Washington County, Colorado is in USDA Zone 5b. The average last spring frost is May 10 and the first fall frost is October 5, giving you a growing season of approximately 148 days.

At an elevation of 6,091 feet, Washington County receives approximately 13 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Daylily during the growing season. 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
Washington County, CO (Zone 5b) Short season
148 days
Last Spring Frost May 10
148 growing days
First Fall Frost October 5

Washington County Soil Profile

Soil Type

Loam

Soil pH

6.8-8.3

Drainage

Well Drained

Daylily Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 28 Transplant: May 16 🌸 Bloom: Aug 8 – Nov 7
Recommended (50%) ✗ May not fit
Start indoors: Mar 8 Transplant: May 24 🌸 Bloom: Aug 16 – Nov 15
Safe Start (90%) ✗ May not fit
Start indoors: Mar 18 Transplant: Jun 3 🌸 Bloom: Aug 26 – Nov 25

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 Washington County

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

Soil pH

Your soil pH (6.8–8.3) is more alkaline than Daylily prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). 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 148-day season

Sow every 6.9 weeks. Last sowing by Jul 07 to harvest before frost.

Daylily Water Budget

Plant needs
0.5″/week
Rainfall provides
0.4″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 207 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1" 0" ❄️ Dormant
Apr 1.4" 0" ❄️ Dormant
May 2.2" 1.5" 0.7" 💧 Light watering
Jun 2.2" 1" 1.2" 🚿 Regular watering
Jul 2.2" 1.2" 1" 💧 Light watering
Aug 2.2" 1.5" 0.7" 💧 Light watering
Sep 2.2" 1.1" 1.1" 🚿 Regular watering
Oct 2.2" 1.1" 1.1" 🚿 Regular watering
Nov 0.9" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Washington 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 ~1,031 GDD — county provides 2,035 GDD Excellent fit

Daylily Planting Timeline — Washington County, CO

Daylily Planting Calendar

Activity When Date Range
Start Indoors March 8 Mar 8 – Mar 22
Transplant Outdoors May 24 May 24 – Jun 7
Bloom August 16 Aug 16 – Nov 15

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Transplant Outdoors
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 · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

148 days in Washington County

Growing Tips for Daylily in Washington County

Direct sow Daylily outdoors after May 10 in Washington County when soil has warmed and frost danger has passed.

Washington County receives only 13" 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 Washington County, CO?

Washington County is in Zone 5b with an average last frost of May 10. Plan your Daylily planting based on this frost date — see the calendar above for exact timing.

What planting zone is Washington County, CO?

Washington County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 10 and first fall frost is October 5.

When should I plant Daylily in Washington County County, ?

In Washington County County, , plant Daylily after the last frost (around May 10) and before the first frost (around October 5). Best results when soil holds above 50°F.

What growing zone is Washington County County, for Daylily?

Washington County County sits in USDA Zone 5b. Daylily grows reliably in zones 3a through 10b, so it's a good fit here.

Can Daylily grow in Washington County County's climate?

Yes — Daylily grows well in Washington County County's temperate climate. Washington County County averages a 148-day frost-free season, with last frost around May 10 and first frost around October 5.

🌱

Your Washington County Garden Planner — Free

A 22-page printable planner built for Washington County (Zone 5b). 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 Washington County, CO. Local conditions may vary. Last updated: June 2026.

Sources & credits

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