When to plant Chard in Mark, IL
Plant Chard in Mark after April 21; the prime window is April 7–April 28. A second sowing from August 4 to August 18 extends the harvest into fall.
When to Plant Chard in Mark, IL
This month in Putnam County, Illinois
Your Putnam County, Illinois 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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Basket week: chard
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
Looking ahead to August
- First harvests: chard
- Fall sowing: 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.
Mark, Illinois is in USDA Zone 5b. The average last spring frost is April 21 and the first fall frost is October 13, giving you a growing season of approximately 175 days.
At an elevation of 582 feet, Putnam County receives approximately 41.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Chard during the growing season.
Mark Soil Profile
Soil Type
Silt Loam
Soil pH
6-6.7
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 Mark
How your county's soil matches Chard's growing requirements.
Soil pH
Your soil pH (6.0–6.7) is within Chard's preferred range (6.0–7.0).
Soil Texture
The silt loam soil in Putnam County is excellent for Chard — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Chard.
Organic Matter
Organic matter is excellent (4.3%) — 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 14 to harvest before frost.
For a dedicated fall crop, sow by Aug 04.
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 | — | 2" | 0" | ❄️ Dormant |
| Mar | — | 3.1" | 0" | ❄️ Dormant |
| Apr | 3.5" | 3.6" | 0" | ✅ Rainfall sufficient |
| May | 3.5" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 5.2" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 5" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 4.3" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 3.3" | 0.2" | 💧 Light watering |
| Oct | 3.5" | 3.3" | 0.2" | 💧 Light watering |
| Nov | — | 3.2" | 0" | ❄️ Dormant |
| Dec | — | 2.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Putnam 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 — Mark, IL
Chard Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 17 | Mar 17 – Mar 31 |
| Transplant Outdoors | April 21 | Apr 21 – May 5 |
| Direct Sow | April 7 | Apr 7 – Apr 28 |
| Harvest | June 16 | Jun 16 – Aug 4 |
| Fall Sowing | August 4 | Aug 4 – Aug 18 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | 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 · Only during dry spells
📅 Days to Maturity
50–60 days
🧪 Soil pH
Needs 6–7 · Your soil: ideal
🗺️ USDA Zone
Zone 5b
📆 Growing Season
175 days in Putnam County
Growing Tips for Chard in Mark
Direct sow Chard outdoors after April 21 in Putnam 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
When should I plant Chard in Mark, IL?
In Mark, IL, plant Chard after the last frost (around April 21) and before the first frost (around October 13). Best results when soil holds above 50°F.
What growing zone is Mark, IL for Chard?
Mark sits in USDA Zone 5b. Chard grows reliably in zones 2a through 11b, so it's a good fit here.
Can Chard grow in Mark's climate?
Yes — Chard grows well in Mark's temperate climate. Mark averages a 175-day frost-free season, with last frost around April 21 and first frost around October 13.
Your Putnam County Garden Planner — Free
A 22-page printable planner built for Putnam 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.