When to Plant Chard in Asotin County, WA
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.
Asotin County, Washington is in USDA Zone 6b. The average last spring frost is May 9 and the first fall frost is September 30, giving you a growing season of approximately 144 days.
At an elevation of 2,029 feet, Asotin County receives approximately 14 inches of rainfall annually with predominantly silt 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.
Asotin County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.5
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 Asotin County
How your county's soil matches Chard's growing requirements.
Soil pH
Your soil pH (5.5–6.5) overlaps with Chard's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Asotin County is excellent for Chard — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.7%) — Chard will thrive.
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 01 to harvest before frost.
For a dedicated fall crop, sow by Jul 22.
Plant Water Budget
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 | — | 2" | 0" | ❄️ Dormant |
| Feb | — | 1.7" | 0" | ❄️ Dormant |
| Mar | — | 1.5" | 0" | ❄️ Dormant |
| Apr | — | 0.9" | 0" | ❄️ Dormant |
| May | 3.5" | 0.8" | 2.7" | 🚿 Regular watering |
| Jun | 3.5" | 0.6" | 2.9" | 🚿 Regular watering |
| Jul | 3.5" | 0.2" | 3.3" | 🚿 Regular watering |
| Aug | 3.5" | 0.3" | 3.2" | 🚿 Regular watering |
| Sep | 3.5" | 0.5" | 3" | 🚿 Regular watering |
| Oct | — | 1.2" | 0" | ❄️ Dormant |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Asotin 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 — Asotin County, WA
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 22 | Jul 22 – Aug 5 |
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 6b
📆 Growing Season
144 days in Asotin County
Growing Tips for Chard in Asotin County
Direct sow Chard outdoors after May 09 in Asotin 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 Asotin County, WA?
Asotin County is in Zone 6b 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 Asotin County, WA?
Asotin County, Washington is in USDA Hardiness Zone 6b. The average last spring frost is May 9 and first fall frost is September 30.
Plan Your Garden with Confidence
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