When to plant Chard in Union County County,
In Union County County, plant Chard in spring between April 9 and April 30, once soil temps hold above 50°F. Union County County's last frost averages April 23, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between August 2 and August 16 — roughly 60 days before the first frost on October 11.
When to Plant Chard in Union County, IA
This month in Union County, Iowa
June is a pivotal month for Union County, Iowa gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Pick chard
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Coming up in July — start thinking about
- First harvests: 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.
Union County, Iowa is in USDA Zone 5b. The average last spring frost is April 23 and the first fall frost is October 11, giving you a growing season of approximately 171 days.
At an elevation of 1,311 feet, Union County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Chard to ensure they mature before fall.
Union County Soil Profile
Soil Type
Silt Loam
Soil pH
6.3-7.3
Drainage
Well Drained
Chard 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 Union County
How your county's soil matches Chard's growing requirements.
Soil pH
Your soil pH (6.3–7.3) overlaps with Chard's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Union County is excellent for Chard — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.8%) — 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 12 to harvest before frost.
For a dedicated fall crop, sow by Aug 02.
Chard 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 | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 1.8" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | 3.5" | 4.1" | 0" | ✅ Rainfall sufficient |
| May | 3.5" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 4.7" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 4.2" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 4" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 3.4" | 0.1" | 💧 Light watering |
| Oct | 3.5" | 3" | 0.5" | 💧 Light watering |
| Nov | — | 2.8" | 0" | ❄️ Dormant |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Union 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 — Union County, IA
Chard 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 18 | Jun 18 – Aug 6 |
| Fall Sowing | August 2 | Aug 2 – Aug 16 |
Plant 1" deep · 15" apart · Rows 24" 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 Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.8"/week · Natural rainfall sufficient
📅 Days to Maturity
50–60 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 5b
📆 Growing Season
171 days in Union County
Growing Tips for Chard in Union County
Direct sow Chard outdoors after April 23 in Union 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 Union County, IA?
Union County is in Zone 5b with an average last frost of April 23. Plan your Chard planting based on this frost date — see the calendar above for exact timing.
What planting zone is Union County, IA?
Union County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 23 and first fall frost is October 11.
When should I plant Chard in Union County, ?
In Union County, , plant Chard after the last frost (around April 23) and before the first frost (around October 11). Best results when soil holds above 50°F.
What growing zone is Union County, for Chard?
Union County sits in USDA Zone 5b. Chard grows reliably in zones 2a through 11b, so it's a good fit here.
Can Chard grow in Union County's climate?
Yes — Chard grows well in Union County's temperate climate. Union County averages a 171-day frost-free season, with last frost around April 23 and first frost around October 11.
Your Union County Garden Planner — Free
A 22-page printable planner built for Union 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.