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When to Plant Hostas in Gunlock, UT

Gunlock, UT Zone 8b June

This month in Gunlock, UT

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Gunlock, UT.

Avg. last frost April 6
Avg. first frost November 1
Soil temp (4") 73°F
Watering Critical
Pest pressure High
Daylight 14.6 hrs
  1. Indoor seed-starting week for hostas

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

  2. Basket week: hostas

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

A few tasks this June that'll pay off in July
  • First harvests: hostas

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Hostas (Hosta spp.) are the undisputed kings of the shade garden, grown primarily for their spectacular mounded foliage in shades of deep green, blue-green, gold, and variegated combinations. Originating in East Asia (Japan, China, Korea), hostas form dense, long-lived clumps that reliably return year after year with minimal care. In summer, tall scapes of lavender or white tubular flowers rise above the foliage — some cultivars (notably H. plantaginea hybrids) are notably fragrant. Extremely adaptable in moist, well-drained soil with consistent shade to part shade.

Gunlock, Utah is in USDA Zone 8b. The average last spring frost is April 6 and the first fall frost is November 1, giving you a growing season of approximately 209 days.

At an elevation of 3,524 feet, Washington County receives approximately 12.7 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Hostas during the growing season. With low rainfall, drip irrigation is essential for growing Hostas successfully. Mulch heavily to conserve soil moisture.

Perennial Blooms in Summer Pollinator-friendly
Gunlock, UT (Zone 8b) Long season
209 days
Last Spring Frost April 6
209 growing days
First Fall Frost November 1

Gunlock Soil Profile

Soil Type

Loam

Soil pH

6.7-8

Drainage

Well Drained

Hostas Planting Risk Windows

Early Start (70% safe) ✓ Fits season (21 days to spare)
Start indoors: Jan 9 Transplant: Mar 13 🌸 Bloom: May 22 – Sep 25
Recommended (50%) ✓ Fits season (13 days to spare)
Start indoors: Feb 2 Transplant: Apr 6 🌸 Bloom: Jun 15 – Oct 19
Safe Start (90%) ✗ May not fit
Start indoors: Mar 25 Transplant: May 27 🌸 Bloom: Aug 5 – Dec 9

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 Gunlock

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

Soil pH

Your soil pH (6.7–8.0) overlaps with Hostas's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Hostas.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Hostas.

How to Plant Hostas

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

Succession Planting Hostas

4
successive plantings in your 209-day season

Sow every 6.9 weeks. Last sowing by Aug 03 to harvest before frost.

Hostas Water Budget

Plant needs
1.0″/week
Rainfall provides
0.3″/week
You supply
1.3″/week
Watering frequency 2-3 times/week
Season total 2,332 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Hostas

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

Month Hostas Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 0.6" 0" ❄️ Dormant
Mar 1.1" 0" ❄️ Dormant
Apr 4.3" 1.2" 3.1" 🚿 Regular watering
May 4.3" 1.4" 2.9" 🚿 Regular watering
Jun 4.3" 0.9" 3.4" 🚿 Regular watering
Jul 4.3" 1.2" 3.1" 🚿 Regular watering
Aug 4.3" 1.4" 2.9" 🚿 Regular watering
Sep 4.3" 0.9" 3.4" 🚿 Regular watering
Oct 4.3" 1.2" 3.1" 🚿 Regular watering
Nov 4.3" 1" 3.3" 🚿 Regular watering
Dec 0.8" 0" ❄️ Dormant

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

Hostas 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.

Hostas needs ~1,312 GDD — county provides 3,657 GDD Excellent fit

Hostas Planting Timeline — Gunlock, UT

Hostas Planting Calendar

Activity When Date Range
Start Indoors February 2 Feb 2 – Feb 16
Transplant Outdoors April 6 Apr 6 – Apr 20
Bloom June 15 Jun 15 – Oct 19

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

209 days in Washington County

Growing Tips for Hostas in Gunlock

Direct sow Hostas outdoors after April 06 in Washington County when soil has warmed and frost danger has passed.

Washington County receives only 13" of rain annually. Hostas needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant bare-root crowns or divisions in early spring just as new growth emerges, or in fall at least 6 weeks before hard freeze. Choose a site with morning sun and afternoon shade in Zones 6+; deeper shade is acceptable but reduces vigor and bloom. Keep consistently moist but never waterlogged. Apply a 2–3 inch mulch layer to conserve moisture and suppress weeds. Slugs are the primary pest — use iron phosphate bait if damage is significant. Deer will browse hostas heavily in most regions; protect with fencing or repellents. Divide every 3–5 years in spring to rejuvenate. Fall planting (Zones 4+) is equally effective as spring planting when soil stays workable. Year 2+ plants reach full size and flower most reliably; first-year divisions may produce limited flower spikes.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

🌱

Your Washington County Garden Planner — Free

A 22-page printable planner built for Washington County (Zone 8b). 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, UT. Local conditions may vary. Last updated: June 2026.