When to plant Hostas in Johnson County County,
Plant Hostas in Johnson County County during the brief April 15–April 29 window. With 201 frost-free days, fall plantings can't mature before October 26.
When to Plant Hostas in Johnson County, KS
What to do in June
We've pulled the most time-sensitive tasks for Johnson County, Kansas this June and put them front and centre. Tackle them in order.
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Sow hostas in trays indoors
Starting these indoors now means sturdy transplants ready the moment your soil warms up.
July will be here before you know it — start on
- First harvests: hostas
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.
Johnson County, Kansas is in USDA Zone 6b. The average last spring frost is April 8 and the first fall frost is October 26, giving you a growing season of approximately 201 days.
At an elevation of 768 feet, Johnson County receives approximately 27.6 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Hostas during the growing season.
Johnson County Soil Profile
Soil Type
Loam
Soil pH
6.8-7.2
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 Johnson County
How your county's soil matches Hostas's growing requirements.
Soil pH
Your soil pH (6.8–7.2) is within Hostas's preferred range (6.0–7.5).
Soil Texture
The loam soil in Johnson County is excellent for Hostas — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.2%) — Hostas will thrive.
How to Plant Hostas
Succession Planting Hostas
Sow every 6.9 weeks. Last sowing by Jul 28 to harvest before frost.
Hostas Water Budget
Water stress score is 6/10 — 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 | — | 0.8" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | — | 1.9" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| May | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Jun | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Jul | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Aug | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Sep | 4.3" | 2.3" | 2" | 💧 Light watering |
| Oct | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Nov | — | 1" | 0" | ❄️ Dormant |
| Dec | — | 0.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Johnson 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 — Johnson County, KS
Hostas Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 28 | Jan 28 – Feb 11 |
| Transplant Outdoors | April 15 | Apr 15 – Apr 29 |
| Bloom | July 1 | Jul 1 – Oct 21 |
Plant 1" deep · 24" apart · Rows 30" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors |
| March | — |
| April | Transplant Outdoors |
| May | — |
| June | — |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
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: ideal
🗺️ USDA Zone
Zone 6b
📆 Growing Season
201 days in Johnson County
Growing Tips for Hostas in Johnson County
Direct sow Hostas outdoors after April 08 in Johnson County when soil has warmed and frost danger has passed.
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 Johnson County, KS?
Johnson County is in Zone 6b with an average last frost of April 8. Plan your Hostas planting based on this frost date — see the calendar above for exact timing.
What planting zone is Johnson County, KS?
Johnson County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 8 and first fall frost is October 26.
When should I plant Hostas in Johnson County County, ?
In Johnson County County, , plant Hostas after the last frost (around April 8) and before the first frost (around October 26). Best results when soil holds above 50°F.
What growing zone is Johnson County County, for Hostas?
Johnson County County sits in USDA Zone 6b. Hostas grows reliably in zones 3a through 9a, so it's a good fit here.
Can Hostas grow in Johnson County County's climate?
Yes — Hostas grows well in Johnson County County's temperate climate. Johnson County County averages a 201-day frost-free season, with last frost around April 8 and first frost around October 26.
Your Johnson County Garden Planner — Free
A 22-page printable planner built for Johnson County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.