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When to plant Hostas in Coconino County, AZ

In Coconino County, Hostas is a single-season spring crop — there's no second fall window. Plant June 4–June 18 for an 60–90-day harvest, finishing well before the September 27 first frost.

When to Plant Hostas in Coconino County, AZ

Coconino County, Arizona Zone 7a August

Your August planting checklist for Coconino County, Arizona

Welcome to August in Zone 7a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 28
Avg. first frost September 27
Soil temp (4") 56°F
Watering Moderate
Pest pressure High
Daylight 13.4 hrs
  1. Sow hostas in trays indoors

    These need a head start before your last frost (May 28). Sow into cells now so you're ready to transplant in a few weeks.

  2. Collect hostas at their peak

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Get ahead of September
  • 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.

Coconino County, Arizona is in USDA Zone 7a. The average last spring frost is May 28 and the first fall frost is September 27, giving you a growing season of approximately 122 days.

At an elevation of 7,869 feet, Coconino County receives approximately 13.9 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Hostas may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Hostas will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Hostas successfully. Mulch heavily to conserve soil moisture.

Perennial Blooms in Summer Pollinator-friendly
Coconino County, AZ (Zone 7a) Short season
122 days
Last Spring Frost May 28
122 growing days
First Fall Frost September 27

Coconino County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.6

Drainage

Well Drained

Hostas Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 6 Transplant: Apr 24 🌸 Bloom: Jul 3 – Nov 6
Recommended (50%) ✗ May not fit
Start indoors: Mar 19 Transplant: Jun 4 🌸 Bloom: Aug 13 – Dec 17
Safe Start (90%) ✓ Fits season (296 days to spare)
Start indoors: Apr 15 Transplant: Jul 1 🌸 Bloom: Sep 9 – Jan 13

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 Coconino County

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

Soil pH

Your soil pH (7.2–8.6) is more alkaline than Hostas prefers (6.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Coconino County warms quickly in spring but drains fast. Hostas will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Hostas.

Organic Matter

Organic matter is low (0.8%). Add 2-3 inches of compost before planting Hostas.

How to Plant Hostas

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

Succession Planting Hostas

2
successive plantings in your 122-day season

Sow every 6.9 weeks. Last sowing by Jun 29 to harvest before frost.

Hostas Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 1,070 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 0.7" 0" ❄️ Dormant
Mar 0.8" 0" ❄️ Dormant
Apr 0.4" 0" ❄️ Dormant
May 4.3" 0.3" 4" 🚿 Regular watering
Jun 4.3" 0.4" 3.9" 🚿 Regular watering
Jul 4.3" 2.6" 1.7" 💧 Light watering
Aug 4.3" 3" 1.3" 💧 Light watering
Sep 4.3" 1.7" 2.6" 🚿 Regular watering
Oct 1.3" 0" ❄️ Dormant
Nov 0.8" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Coconino 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 ~1,650 GDD — county provides 2,684 GDD Excellent fit

Hostas Planting Timeline — Coconino County, AZ

Hostas Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 – Apr 2
Transplant Outdoors June 4 Jun 4 – Jun 18
Bloom August 13 Aug 13 – Dec 17

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 Bloom

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: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

122 days in Coconino County

Growing Tips for Hostas in Coconino County

Direct sow Hostas outdoors after May 28 in Coconino County when soil has warmed and frost danger has passed.

Sandy soil in Coconino County dries quickly — mulch Hostas with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 96°F in Coconino County, provide afternoon shade for Hostas and water deeply in the morning.

Coconino County receives only 14" 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 Coconino County, AZ?

Coconino County is in Zone 7a with an average last frost of May 28. Plan your Hostas planting based on this frost date — see the calendar above for exact timing.

What planting zone is Coconino County, AZ?

Coconino County, Arizona is in USDA Hardiness Zone 7a. The average last spring frost is May 28 and first fall frost is September 27.

When should I plant Hostas in Coconino County, AZ?

In Coconino County, AZ, plant Hostas after the last frost (around May 28) and before the first frost (around September 27). Best results when soil holds above 50°F.

What growing zone is Coconino County, AZ for Hostas?

Coconino County sits in USDA Zone 7a. Hostas grows reliably in zones 3a through 9a, so it's a good fit here.

Can Hostas grow in Coconino County's climate?

Yes — Hostas grows well in Coconino County's temperate climate. Coconino County averages a 122-day frost-free season, with last frost around May 28 and first frost around September 27.

🌱

Your Coconino County Garden Planner — Free

A 22-page printable planner built for Coconino 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 Coconino County, AZ. Local conditions may vary. Last updated: August 2026.

Sources & credits

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