When to Plant Mizuna in Harding County, SD
Harding County, South Dakota gardeners: here's your May plan
Here's what deserves your attention in Harding County, South Dakota this month. Everything below is tailored to Zone 4b and timed around your local frost dates.
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Move mizuna from tray to bed
Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.
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Put mizuna seeds straight in the ground
These tolerate cool soil, so you're not gambling by sowing now.
June will be here before you know it — start on
- Starting indoors: mizuna
- First harvests: mizuna
- Fall sowing: mizuna
Mizuna is a mild-flavored Japanese mustard green with feathery, deeply serrated leaves. It is fast-growing and makes an excellent addition to salads and stir-fries.
Harding County, South Dakota is in USDA Zone 4b. The average last spring frost is May 16 and the first fall frost is September 22, giving you a growing season of approximately 129 days.
At an elevation of 750 feet, Harding County receives approximately 29.3 inches of rainfall annually with predominantly loam soil. Summer highs average 78°F, so choose short-season varieties of Mizuna to ensure they mature before fall.
Harding County Soil Profile
Soil Type
Loam
Soil pH
6.3-7.7
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 Harding County
How your county's soil matches Mizuna's growing requirements.
Soil pH
Your soil pH (6.3–7.7) overlaps with Mizuna's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Harding County is excellent for Mizuna — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.7%). Annual compost additions will help Mizuna.
How to Plant Mizuna
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Mizuna
Sow every 3.4 weeks. Last sowing by Aug 08 to harvest before frost.
For a dedicated fall crop, sow by Jun 30.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Mizuna
Mizuna needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Mizuna Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | — | 3.3" | 0" | ❄️ Dormant |
| May | 4.3" | 3.3" | 1" | 💧 Light watering |
| Jun | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Jul | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Aug | 4.3" | 3" | 1.3" | 💧 Light watering |
| Sep | 4.3" | 2.3" | 2" | 💧 Light watering |
| Oct | — | 2.7" | 0" | ❄️ Dormant |
| Nov | — | 2.1" | 0" | ❄️ Dormant |
| Dec | — | 1.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Harding County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Mizuna 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.
Mizuna Planting Timeline — Harding County, SD
Mizuna Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 4 | Apr 4 – Apr 18 |
| Transplant Outdoors | May 16 | May 16 – May 30 |
| Direct Sow | May 9 | May 9 – May 30 |
| Harvest | June 20 | Jun 20 – Jul 18 |
| Fall Sowing | June 30 | Jun 30 – Jul 14 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Fall Sowing Harvest |
| July | Fall Sowing Harvest |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
30–45 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 4b
📆 Growing Season
129 days in Harding County
Growing Tips for Mizuna in Harding County
Direct sow Mizuna outdoors after May 16 in Harding County when soil has warmed and frost danger has passed.
Your generous 129.0-day season in Harding County allows multiple plantings of Mizuna. Sow every 15.0 days for continuous harvest.
Common pests for Mizuna in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow in spring or fall. Harvest outer leaves as needed for a cut-and-come-again approach. Mizuna is one of the most cold-tolerant Asian greens.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Mizuna in Other Locations
Frequently Asked Questions
When should I plant Mizuna in Harding County, SD?
Harding County is in Zone 4b with an average last frost of May 16. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.
What planting zone is Harding County, SD?
Harding County, South Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 16 and first fall frost is September 22.
Your Harding County Garden Planner — Free
A 24-page printable planner built for Harding County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.