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When to Plant Daylily in Pendleton, OR

Umatilla County, Oregon Zone 7a August

What to do in August

We've pulled the most time-sensitive tasks for Umatilla County, Oregon this August and put them front and centre. Tackle them in order.

Avg. last frost April 23
Avg. first frost October 20
Soil temp (4") 78°F
Watering Critical
Pest pressure High
Daylight 13.9 hrs
  1. It's harvest week for daylily

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

September will be here before you know it — start on
  • First harvests: 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.

Pendleton, Oregon is in USDA Zone 7a. The average last spring frost is April 23 and the first fall frost is October 20, giving you a growing season of approximately 180 days.

At an elevation of 2,195 feet, Umatilla County receives approximately 14.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°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
Pendleton, OR (Zone 7a) Moderate season
180 days
Last Spring Frost April 23
180 growing days
First Fall Frost October 20

Pendleton Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.8

Drainage

Well Drained

Daylily Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 4 Transplant: Apr 15 🌸 Bloom: Jun 24 – Oct 28
Recommended (50%) ✗ May not fit
Start indoors: Feb 19 Transplant: Apr 30 🌸 Bloom: Jul 9 – Nov 12
Safe Start (90%) ✗ May not fit
Start indoors: Mar 11 Transplant: May 20 🌸 Bloom: Jul 29 – Dec 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 Pendleton

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

Soil pH

Your soil pH (5.2–6.8) overlaps with Daylily's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.1%) — Daylily will thrive.

How to Plant Daylily

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

Succession Planting Daylily

3
successive plantings in your 180-day season

Sow every 6.9 weeks. Last sowing by Jul 22 to harvest before frost.

Daylily Water Budget

Plant needs
0.5″/week
Rainfall provides
0.3″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 255 gal / 100 sq ft

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 1.8" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 2.2" 1.1" 1.1" 🚿 Regular watering
May 2.2" 0.9" 1.3" 🚿 Regular watering
Jun 2.2" 0.6" 1.6" 🚿 Regular watering
Jul 2.2" 0.3" 1.9" 🚿 Regular watering
Aug 2.2" 0.3" 1.9" 🚿 Regular watering
Sep 2.2" 0.6" 1.6" 🚿 Regular watering
Oct 2.2" 1.4" 0.8" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Umatilla 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 ~1,088 GDD — county provides 2,610 GDD Excellent fit

Daylily Planting Timeline — Pendleton, OR

Daylily Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 – Mar 5
Transplant Outdoors April 30 Apr 30 – May 14
Bloom July 9 Jul 9 – Nov 12

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April Transplant Outdoors
May Transplant Outdoors
June
July Bloom
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: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

180 days in Umatilla County

Growing Tips for Daylily in Pendleton

Direct sow Daylily outdoors after April 23 in Umatilla County when soil has warmed and frost danger has passed.

Umatilla County receives only 15" 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 →

🌱

Your Umatilla County Garden Planner — Free

A 22-page printable planner built for Umatilla County (Zone 7a). 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 Umatilla County, OR. Local conditions may vary. Last updated: August 2026.