When to plant Carrots in Custer County, ID
Custer County sits in USDA Zone 5b. Plant Carrots between June 4 (after last frost on June 18) and June 25. A second sowing from June 27 to July 11 extends the harvest into fall.
When to Plant Carrots in Custer County, ID
August in Custer County, Idaho — your action list
We've pulled the most time-sensitive tasks for Custer County, Idaho this August and put them front and centre. Tackle them in order.
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Harvest carrots as they ripen
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
A few tasks this August that'll pay off in September
- First harvests: carrots
Carrots are a popular root vegetable available in orange, purple, white, and yellow varieties. They are rich in beta-carotene and have a sweet, earthy flavor.
Custer County, Idaho is in USDA Zone 5b. The average last spring frost is June 18 and the first fall frost is September 5, giving you a growing season of approximately 79 days.
At an elevation of 5,189 feet, Custer County receives approximately 20.6 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Carrots to ensure they mature before fall.
Custer County Soil Profile
Soil Type
Loam
Soil pH
6.3-8
Drainage
Well Drained
Carrots 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 Custer County
How your county's soil matches Carrots's growing requirements.
Soil pH
Your soil pH (6.3–8.0) is more alkaline than Carrots prefers (6.0–6.8). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Custer County is excellent for Carrots — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.3%). Annual compost additions will help Carrots.
How to Plant Carrots
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Carrots Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Carrots
Carrots 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 | Carrots Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 1.7" | 0" | ❄️ Dormant |
| Apr | — | 2.4" | 0" | ❄️ Dormant |
| May | — | 2.3" | 0" | ❄️ Dormant |
| Jun | 3.5" | 1.5" | 2" | 🚿 Regular watering |
| Jul | 3.5" | 2" | 1.5" | 💧 Light watering |
| Aug | 3.5" | 2.1" | 1.4" | 💧 Light watering |
| Sep | 3.5" | 1.7" | 1.8" | 🚿 Regular watering |
| Oct | — | 1.6" | 0" | ❄️ Dormant |
| Nov | — | 1.4" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Custer County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Carrots 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.
Carrots Planting Timeline — Custer County, ID
Carrots Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | June 4 | Jun 4 – Jun 25 |
| Harvest | August 6 | Aug 6 – Sep 10 |
| Fall Sowing | June 27 | Jun 27 – Jul 11 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Direct Sow Fall Sowing |
| July | Fall Sowing |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · Natural rainfall sufficient
📅 Days to Maturity
60–80 days
🧪 Soil pH
Needs 6–6.8 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5b
📆 Growing Season
79 days in Custer County
Growing Tips for Carrots in Custer County
Direct sow Carrots outdoors after June 18 in Custer County when soil has warmed and frost danger has passed.
Your 79.0-day growing season in Custer County is tight for Carrots (60.0-80.0 days to maturity). Start indoors and choose early-maturing varieties.
Common pests for Carrots in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.
General growing tips
Sow seeds directly in loose, stone-free soil for straight roots. Keep soil moist until germination which can take 2-3 weeks. Thin seedlings to 2 inches apart.
Recommended Carrots Varieties for Custer County
Fast-maturing varieties for your season
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 1/2 mile from Queen Anne's Lace (wild carrot). Biennial — requires two seasons.
Carrots in Other Locations
Frequently Asked Questions
When should I plant Carrots in Custer County, ID?
Custer County is in Zone 5b with an average last frost of June 18. Plan your Carrots planting based on this frost date — see the calendar above for exact timing.
What planting zone is Custer County, ID?
Custer County, Idaho is in USDA Hardiness Zone 5b. The average last spring frost is June 18 and first fall frost is September 5.
When should I plant Carrots in Custer County, ID?
In Custer County, ID, plant Carrots after the last frost (around June 18) and before the first frost (around September 5). Best results when soil holds above 50°F.
What growing zone is Custer County, ID for Carrots?
Custer County sits in USDA Zone 5b. Carrots grows reliably in zones 3a through 10b, so it's a good fit here.
Can Carrots grow in Custer County's climate?
Yes — Carrots grows well in Custer County's temperate climate. Custer County averages a 79-day frost-free season, with last frost around June 18 and first frost around September 5.
Your Custer County Garden Planner — Free
A 22-page printable planner built for Custer 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.