When to Plant Hostas in Summit County, UT
Summit County, Utah gardeners: here's your June plan
If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.
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Move hostas from tray to bed
Your last frost (June 10) has passed. These warm-season crops can handle outdoor soil now.
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.
Summit County, Utah is in USDA Zone 5b. The average last spring frost is June 10 and the first fall frost is September 12, giving you a growing season of approximately 94 days.
At an elevation of 8,145 feet, Summit County receives approximately 24.8 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Hostas during the growing season.
Summit County Soil Profile
Soil Type
Loam
Soil pH
6.4-8.3
Drainage
Well Drained
Hostas Planting Risk Windows
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 Summit County
How your county's soil matches Hostas's growing requirements.
Soil pH
Your soil pH (6.4–8.3) overlaps with Hostas's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Summit County is excellent for Hostas — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.3%). Annual compost additions will help Hostas.
How to Plant Hostas
Hostas Water Budget
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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | — | 2.9" | 0" | ❄️ Dormant |
| May | — | 2.9" | 0" | ❄️ Dormant |
| Jun | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Jul | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Aug | 4.3" | 2.5" | 1.8" | 💧 Light watering |
| Sep | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Oct | — | 2.1" | 0" | ❄️ Dormant |
| Nov | — | 2" | 0" | ❄️ Dormant |
| Dec | — | 1.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Summit 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 Planting Timeline — Summit County, UT
Hostas Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 1 | Apr 1 – Apr 15 |
| Transplant Outdoors | June 24 | Jun 24 – Jul 8 |
| Bloom | September 16 | Sep 16 – Dec 16 |
Plant 1" deep · 24" apart · Rows 30" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | — |
| June | Transplant Outdoors |
| July | Transplant Outdoors |
| August | — |
| September | Bloom |
| October | Bloom |
| November | Bloom |
| December | Bloom |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 5b
📆 Growing Season
94 days in Summit County
Growing Tips for Hostas in Summit County
Direct sow Hostas outdoors after June 10 in Summit County when soil has warmed and frost danger has passed.
Your 94.0-day growing season in Summit County is tight for Hostas (60.0-90.0 days to maturity). Start indoors and choose early-maturing varieties.
Summit County receives only 25" 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 →
Hostas in Other Locations
Frequently Asked Questions
When should I plant Hostas in Summit County, UT?
Summit County is in Zone 5b with an average last frost of June 10. Plan your Hostas planting based on this frost date — see the calendar above for exact timing.
What planting zone is Summit County, UT?
Summit County, Utah is in USDA Hardiness Zone 5b. The average last spring frost is June 10 and first fall frost is September 12.
Your Summit County Garden Planner — Free
A 22-page printable planner built for Summit 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.