When to Plant Currants in Johnson County, IA
Currants are small, tart berries that grow on attractive shrubs in red, white, and black varieties. They are prized for jams, jellies, and liqueurs.
Johnson County, Iowa is in USDA Zone 5a. The average last spring frost is April 24 and the first fall frost is October 11, giving you a growing season of approximately 170 days.
At an elevation of 1,204 feet, Johnson County receives approximately 40.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Currants during the growing season.
Johnson County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-7.3
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 Johnson County
How your county's soil matches Currants's growing requirements.
Soil pH
Your soil pH (6.2–7.3) is more alkaline than Currants prefers (6.0–6.5). Add sulfur or peat moss to lower pH.
Soil Texture
The silt loam soil in Johnson County is excellent for Currants — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.9%). Annual compost additions will help Currants.
How to Plant Currants
Plant Water Budget
Monthly Watering Guide for Currants
Currants needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.
| Month | Currants Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 2" | 0" | ❄️ Dormant |
| Mar | — | 2.8" | 0" | ❄️ Dormant |
| Apr | 3.5" | 3.7" | 0" | ✅ Rainfall sufficient |
| May | 3.5" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 5.4" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 4.5" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 3.6" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 3.6" | 0" | ✅ Rainfall sufficient |
| Oct | 3.5" | 3.4" | 0.1" | 💧 Light watering |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 2.3" | 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.
Currants 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.
Currants Planting Timeline — Johnson County, IA
Currants Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 15 | May 15 – May 29 |
· 48" apart · Rows 72" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.8"/week · Natural rainfall sufficient
📅 Days to Maturity
730–1095 days
🧪 Soil pH
Needs 6–6.5 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5a
📆 Growing Season
170 days in Johnson County
Growing Tips for Currants in Johnson County
Direct sow Currants outdoors after April 24 in Johnson County when soil has warmed and frost danger has passed.
Your 170.0-day growing season in Johnson County is tight for Currants (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.
General growing tips
Plant in a sheltered location with morning sun. Prune out wood older than 3 years to encourage new fruiting wood. Mulch heavily to keep roots cool and moist.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Currants in Other Locations
Frequently Asked Questions
When should I plant Currants in Johnson County, IA?
Johnson County is in Zone 5a with an average last frost of April 24. Plan your Currants planting based on this frost date — see the calendar above for exact timing.
What planting zone is Johnson County, IA?
Johnson County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 24 and first fall frost is October 11.
Plan Your Garden with Confidence
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