Blog

When to plant Hostas in Weld County County,

In Weld County County, Hostas is a single-season spring crop — there's no second fall window. Plant May 16–May 30 for an 90-day harvest, finishing well before the October 7 first frost.

When to Plant Hostas in Weld County, CO

Weld County, Colorado Zone 5b June

June to-do list for Weld County, Colorado

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

Avg. last frost May 2
Avg. first frost October 7
Soil temp (4") 50°F
Watering High
Pest pressure High
Daylight 14.9 hrs
July will be here before you know it — start on
  • Starting indoors: hostas

Instant PDF download. No spam, unsubscribe any time.

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.

Weld County, Colorado is in USDA Zone 5b. The average last spring frost is May 2 and the first fall frost is October 7, giving you a growing season of approximately 158 days.

At an elevation of 6,992 feet, Weld County receives approximately 18.8 inches of rainfall annually with predominantly loam soil. Summer highs average 87°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
Weld County, CO (Zone 5b) Moderate season
158 days
Last Spring Frost May 2
158 growing days
First Fall Frost October 7
Share this guide:

Weld County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.1

Drainage

Well Drained

Hostas Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 16 Transplant: May 11 🌸 Bloom: Aug 3 – Nov 2
Recommended (50%) ✗ May not fit
Start indoors: Feb 21 Transplant: May 16 🌸 Bloom: Aug 8 – Nov 7
Safe Start (90%) ✗ May not fit
Start indoors: Mar 10 Transplant: Jun 2 🌸 Bloom: Aug 25 – Nov 24

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 Weld County

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

Soil pH

Your soil pH (6.6–8.1) overlaps with Hostas's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Hostas.

How to Plant Hostas

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

Succession Planting Hostas

3
successive plantings in your 158-day season

Sow every 6.9 weeks. Last sowing by Jul 09 to harvest before frost.

Hostas Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 844 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.4" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 2.1" 0" ❄️ Dormant
May 4.3" 2.3" 2" 💧 Light watering
Jun 4.3" 1.4" 2.9" 🚿 Regular watering
Jul 4.3" 1.7" 2.6" 🚿 Regular watering
Aug 4.3" 1.8" 2.5" 🚿 Regular watering
Sep 4.3" 1.7" 2.6" 🚿 Regular watering
Oct 4.3" 1.7" 2.6" 🚿 Regular watering
Nov 1.2" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Weld 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 ~1,144 GDD — county provides 2,409 GDD Excellent fit

Hostas Planting Timeline — Weld County, CO

Hostas Planting Calendar

Activity When Date Range
Start Indoors February 21 Feb 21 – Mar 7
Transplant Outdoors May 16 May 16 – May 30
Bloom August 8 Aug 8 – Nov 7

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

158 days in Weld County

Growing Tips for Hostas in Weld County

Direct sow Hostas outdoors after May 02 in Weld County when soil has warmed and frost danger has passed.

Weld County receives only 19" 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 →

Frequently Asked Questions

When should I plant Hostas in Weld County, CO?

Weld County is in Zone 5b with an average last frost of May 2. Plan your Hostas planting based on this frost date — see the calendar above for exact timing.

What planting zone is Weld County, CO?

Weld County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 2 and first fall frost is October 7.

When should I plant Hostas in Weld County County, ?

In Weld County County, , plant Hostas after the last frost (around May 2) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Weld County County, for Hostas?

Weld County County sits in USDA Zone 5b. Hostas grows reliably in zones 3a through 9a, so it's a good fit here.

Can Hostas grow in Weld County County's climate?

Yes — Hostas grows well in Weld County County's temperate climate. Weld County County averages a 158-day frost-free season, with last frost around May 2 and first frost around October 7.

🌱

Your Weld County Garden Planner — Free

A 22-page printable planner built for Weld 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Weld County, CO. 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.