When to Plant Chard in Washington County, ID
What to do in May
Here's what deserves your attention in Washington County, Idaho this month. Everything below is tailored to Zone 7a and timed around your local frost dates.
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Harden off and plant chard
Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.
June prep starts now
- Starting indoors: chard
Swiss chard is a colorful, heat-tolerant green with large crinkled leaves and vibrant stalks in red, yellow, and white. Both the leaves and stems are edible and nutritious.
Washington County, Idaho is in USDA Zone 7a. The average last spring frost is May 9 and the first fall frost is October 1, giving you a growing season of approximately 145 days.
At an elevation of 4,048 feet, Washington County receives approximately 17.9 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Chard during the growing season. With low rainfall, drip irrigation is essential for growing Chard successfully. Mulch heavily to conserve soil moisture.
Washington County Soil Profile
Soil Type
Loam
Soil pH
6.2-7.8
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 Washington County
How your county's soil matches Chard's growing requirements.
Soil pH
Your soil pH (6.2–7.8) overlaps with Chard's range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in Washington County is excellent for Chard — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Chard.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Chard.
How to Plant Chard
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Chard
Sow every 5.7 weeks. Last sowing by Aug 02 to harvest before frost.
For a dedicated fall crop, sow by Jul 23.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Chard
Chard 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 | Chard Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.1" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 1.9" | 0" | ❄️ Dormant |
| Apr | — | 1.7" | 0" | ❄️ Dormant |
| May | 3.5" | 2" | 1.5" | 💧 Light watering |
| Jun | 3.5" | 1.2" | 2.3" | 🚿 Regular watering |
| Jul | 3.5" | 1.6" | 1.9" | 🚿 Regular watering |
| Aug | 3.5" | 1.7" | 1.8" | 🚿 Regular watering |
| Sep | 3.5" | 1.5" | 2" | 🚿 Regular watering |
| Oct | 3.5" | 1.5" | 2" | 🚿 Regular watering |
| Nov | — | 1.4" | 0" | ❄️ Dormant |
| Dec | — | 1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Washington County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Chard 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.
Chard Planting Timeline — Washington County, ID
Chard Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 4 | Apr 4 – Apr 18 |
| Transplant Outdoors | May 9 | May 9 – May 23 |
| Direct Sow | April 25 | Apr 25 – May 16 |
| Harvest | July 4 | Jul 4 – Aug 22 |
| Fall Sowing | July 23 | Jul 23 – Aug 6 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Fall Sowing Harvest |
| August | Fall Sowing Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.8"/week · 1-2 times/week
📅 Days to Maturity
50–60 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 7a
📆 Growing Season
145 days in Washington County
Growing Tips for Chard in Washington County
Direct sow Chard outdoors after May 09 in Washington County when soil has warmed and frost danger has passed.
General growing tips
Direct sow or transplant after last frost. Harvest outer leaves regularly to encourage continuous production. Chard tolerates both heat and light frost.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Chard in Other Locations
Frequently Asked Questions
When should I plant Chard in Washington County, ID?
Washington County is in Zone 7a with an average last frost of May 9. Plan your Chard planting based on this frost date — see the calendar above for exact timing.
What planting zone is Washington County, ID?
Washington County, Idaho is in USDA Hardiness Zone 7a. The average last spring frost is May 9 and first fall frost is October 1.
Your Washington County Garden Planner — Free
A 24-page printable planner built for Washington 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.