When to Plant Collard Greens in Yuma County, AZ
Your May planting checklist for Yuma County, Arizona
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
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It's harvest week for collard greens
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
Coming up in June — start thinking about
- First harvests: collard greens
Collard greens are a heat-tolerant member of the cabbage family with large, sturdy leaves. They are a Southern staple and one of the most nutritious leafy greens.
Yuma County, Arizona is in USDA Zone 10a. The average last spring frost is February 10 and the first fall frost is December 1, giving you a growing season of approximately 294 days.
At an elevation of 4,781 feet, Yuma County receives approximately 9.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 92°F, providing good warmth for Collard Greens during the growing season. Sandy soil warms quickly in spring — great for early planting — but Collard Greens will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Collard Greens successfully. Mulch heavily to conserve soil moisture.
Yuma County Soil Profile
Soil Type
Sandy Loam
Soil pH
6.9-8.4
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 Yuma County
How your county's soil matches Collard Greens's growing requirements.
Soil pH
Your soil pH (6.9–8.4) is more alkaline than Collard Greens prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in Yuma County warms quickly in spring but drains fast. Collard Greens will need more frequent watering and regular compost additions to retain nutrients.
Organic Matter
Organic matter is low (0.8%). Add 2-3 inches of compost before planting Collard Greens.
How to Plant Collard Greens
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Collard Greens
Sow every 6.3 weeks. Last sowing by Sep 17 to harvest before frost.
For a dedicated fall crop, sow by Oct 06.
Plant Water Budget
Water stress score is 10/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Collard Greens
Collard Greens 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 | Collard Greens Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 0.6" | 0" | ❄️ Dormant |
| Feb | 3.5" | 0.5" | 3" | 🚿 Regular watering |
| Mar | 3.5" | 0.5" | 3" | 🚿 Regular watering |
| Apr | 3.5" | 0.3" | 3.2" | 🚿 Regular watering |
| May | 3.5" | 0.2" | 3.3" | 🚿 Regular watering |
| Jun | 3.5" | 0.3" | 3.2" | 🚿 Regular watering |
| Jul | 3.5" | 1.8" | 1.7" | 💧 Light watering |
| Aug | 3.5" | 1.9" | 1.6" | 💧 Light watering |
| Sep | 3.5" | 1.4" | 2.1" | 🚿 Regular watering |
| Oct | 3.5" | 0.8" | 2.7" | 🚿 Regular watering |
| Nov | 3.5" | 0.5" | 3" | 🚿 Regular watering |
| Dec | 3.5" | 0.6" | 2.9" | 🚿 Regular watering |
Water needs are for active growing months only (Feb–Dec in Yuma County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Collard Greens 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.
Collard Greens Planting Timeline — Yuma County, AZ
Collard Greens Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 13 | Jan 13 – Jan 27 |
| Transplant Outdoors | February 10 | Feb 10 – Feb 24 |
| Direct Sow | January 20 | Jan 20 – Feb 10 |
| Harvest | April 7 | Apr 7 – Jun 9 |
| Fall Sowing | October 6 | Oct 6 – Oct 20 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Direct Sow |
| February | Transplant Outdoors Direct Sow |
| March | — |
| April | Harvest |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · 2-3 times/week
📅 Days to Maturity
55–75 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 10a
📆 Growing Season
294 days in Yuma County
Growing Tips for Collard Greens in Yuma County
Direct sow Collard Greens outdoors after February 10 in Yuma County when soil has warmed and frost danger has passed.
Sandy soil in Yuma County dries quickly — mulch Collard Greens with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
Common pests for Collard Greens in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors or direct sow 4-6 weeks before last frost. Harvest lower leaves first, leaving the growing tip intact. Flavor improves after exposure to frost.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Collard Greens in Other Locations
Frequently Asked Questions
When should I plant Collard Greens in Yuma County, AZ?
Yuma County is in Zone 10a with an average last frost of February 10. Plan your Collard Greens planting based on this frost date — see the calendar above for exact timing.
What planting zone is Yuma County, AZ?
Yuma County, Arizona is in USDA Hardiness Zone 10a. The average last spring frost is February 10 and first fall frost is December 1.
Your Yuma County Garden Planner — Free
A 24-page printable planner built for Yuma County (Zone 10a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.