When to Plant Persimmon in Union County, OR
Persimmons are ornamental trees producing sweet, honey-flavored fruits in fall. American persimmons are astringent until fully ripe while Asian types can be eaten firm.
Union County, Oregon is in USDA Zone 5b. The average last spring frost is May 12 and the first fall frost is September 26, giving you a growing season of approximately 137 days.
At an elevation of 2,751 feet, Union County receives approximately 23.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Persimmon during the growing season.
Union County Soil Profile
Soil Type
Silt Loam
Soil pH
5.2-6.6
Drainage
Well Drained
Plant 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 Union County
How your county's soil matches Persimmon's growing requirements.
Soil pH
Your soil pH (5.2–6.6) is more acidic than Persimmon prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Union County is excellent for Persimmon — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Persimmon.
Organic Matter
Organic matter is excellent (5.6%) — Persimmon will thrive.
How to Plant Persimmon
Plant Water Budget
Monthly Watering Guide for Persimmon
Persimmon needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Persimmon Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 2.9" | 0" | ❄️ Dormant |
| Feb | — | 2.6" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | — | 1.5" | 0" | ❄️ Dormant |
| May | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Jun | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Jul | 4.3" | 0.4" | 3.9" | 🚿 Regular watering |
| Aug | 4.3" | 0.5" | 3.8" | 🚿 Regular watering |
| Sep | 4.3" | 1" | 3.3" | 🚿 Regular watering |
| Oct | — | 2" | 0" | ❄️ Dormant |
| Nov | — | 3.8" | 0" | ❄️ Dormant |
| Dec | — | 4.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Union County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Persimmon 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.
Persimmon Planting Timeline — Union County, OR
Persimmon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | June 2 | Jun 2 – Jun 16 |
· 120" apart · Rows 144" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Transplant Outdoors |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
1095–2555 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 5b
📆 Growing Season
137 days in Union County
Growing Tips for Persimmon in Union County
Direct sow Persimmon outdoors after May 12 in Union County when soil has warmed and frost danger has passed.
Your 137.0-day growing season in Union County is tight for Persimmon (1095.0-2555.0 days to maturity). Start indoors and choose early-maturing varieties.
Union County receives only 24" of rain annually. Persimmon needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Choose self-fertile varieties or plant male and female trees. American types must be fully soft-ripe before eating. Asian varieties may be eaten when firm. Minimal pruning needed.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Persimmon in Other Locations
Frequently Asked Questions
When should I plant Persimmon in Union County, OR?
Union County is in Zone 5b with an average last frost of May 12. Plan your Persimmon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Union County, OR?
Union County, Oregon is in USDA Hardiness Zone 5b. The average last spring frost is May 12 and first fall frost is September 26.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Union County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
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