When to plant Radicchio in Ada County, ID
Plant Radicchio in Ada County, when soil hits 50°F — usually April 9. Continue planting through April 30 for the spring crop. A second sowing from August 7 to August 21 extends the harvest into fall.
When to Plant Radicchio in Ada County, ID
July in Ada County, Idaho — your action list
Your Ada County, Idaho garden is entering a new phase. Here's what's on the schedule for July and why each task matters now.
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It's harvest week for radicchio
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
A few tasks this July that'll pay off in August
- Fall sowing: radicchio
Radicchio is an Italian chicory with stunning red and white leaves and a pleasantly bitter flavor. It forms tight heads and is used in salads, grilled, or braised.
Ada County, Idaho is in USDA Zone 7a. The average last spring frost is April 23 and the first fall frost is October 16, giving you a growing season of approximately 176 days.
At an elevation of 4,372 feet, Ada County receives approximately 19.8 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Radicchio during the growing season. With low rainfall, drip irrigation is essential for growing Radicchio successfully. Mulch heavily to conserve soil moisture.
Ada County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.7
Drainage
Well Drained
Radicchio 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 Ada County
How your county's soil matches Radicchio's growing requirements.
Soil pH
Your soil pH (6.4–7.7) is more alkaline than Radicchio prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Ada County is excellent for Radicchio — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.3%). Annual compost additions will help Radicchio.
How to Plant Radicchio
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Radicchio
Sow every 6.9 weeks. Last sowing by Jul 28 to harvest before frost.
For a dedicated fall crop, sow by Aug 07.
Radicchio Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Radicchio
Radicchio needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.
| Month | Radicchio Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 1.5" | 0" | ❄️ Dormant |
| Apr | 3" | 2" | 1" | 💧 Light watering |
| May | 3" | 2.4" | 0.6" | 💧 Light watering |
| Jun | 3" | 1.4" | 1.6" | 🚿 Regular watering |
| Jul | 3" | 1.8" | 1.2" | 💧 Light watering |
| Aug | 3" | 2.4" | 0.6" | 💧 Light watering |
| Sep | 3" | 1.5" | 1.5" | 🚿 Regular watering |
| Oct | 3" | 1.8" | 1.2" | 💧 Light watering |
| Nov | — | 1.3" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Ada County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Radicchio 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.
Radicchio Planting Timeline — Ada County, ID
Radicchio Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 19 | Mar 19 – Apr 2 |
| Transplant Outdoors | April 23 | Apr 23 – May 7 |
| Direct Sow | April 9 | Apr 9 – Apr 30 |
| Harvest | June 25 | Jun 25 – Jul 30 |
| Fall Sowing | August 7 | Aug 7 – Aug 21 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.7"/week · Only during dry spells
📅 Days to Maturity
60–80 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 7a
📆 Growing Season
176 days in Ada County
Growing Tips for Radicchio in Ada County
Direct sow Radicchio outdoors after April 23 in Ada County when soil has warmed and frost danger has passed.
Common pests for Radicchio in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
General growing tips
Start in late summer for fall harvest. The red color develops with cool nights and light frost. Harvest when heads are firm and compact.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Radicchio in Other Locations
Frequently Asked Questions
When should I plant Radicchio in Ada County, ID?
Ada County is in Zone 7a with an average last frost of April 23. Plan your Radicchio planting based on this frost date — see the calendar above for exact timing.
What planting zone is Ada County, ID?
Ada County, Idaho is in USDA Hardiness Zone 7a. The average last spring frost is April 23 and first fall frost is October 16.
When should I plant Radicchio in Ada County, ID?
In Ada County, ID, plant Radicchio after the last frost (around April 23) and before the first frost (around October 16). Best results when soil holds above 50°F.
What growing zone is Ada County, ID for Radicchio?
Ada County sits in USDA Zone 7a. Radicchio grows reliably in zones 4a through 10b, so it's a good fit here.
Can Radicchio grow in Ada County's climate?
Yes — Radicchio grows well in Ada County's temperate climate. Ada County averages a 176-day frost-free season, with last frost around April 23 and first frost around October 16.
Your Ada County Garden Planner — Free
A 22-page printable planner built for Ada 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.