When to Plant Mustard Greens in Petersburg Borough, AK
This month in Petersburg Borough, Alaska
Your Petersburg Borough, Alaska garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
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Sow mustard greens in trays indoors
Label every cell. You will absolutely forget which is which otherwise.
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Harvest mustard greens as they ripen
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
Looking ahead to June
- First harvests: mustard greens
Mustard greens are fast-growing brassicas with a spicy, peppery kick. They come in green, red, and purple varieties and are excellent cooked or in salads.
Petersburg Borough, Alaska is in USDA Zone 7b. The average last spring frost is April 23 and the first fall frost is October 20, giving you a growing season of approximately 180 days.
At an elevation of 974 feet, Petersburg Borough receives approximately 17.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 57°F, so choose short-season varieties of Mustard Greens to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Mustard Greens successfully. Mulch heavily to conserve soil moisture.
Petersburg Borough Soil Profile
Soil Type
Silt Loam
Soil pH
4.9-6.3
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 Petersburg Borough
How your county's soil matches Mustard Greens's growing requirements.
Soil pH
Your soil pH (4.9–6.3) is more acidic than Mustard Greens prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Petersburg Borough is excellent for Mustard Greens — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Mustard Greens.
Organic Matter
Organic matter is excellent (6.8%) — Mustard Greens will thrive.
How to Plant Mustard Greens
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Mustard Greens
Sow every 3.4 weeks. Last sowing by Aug 31 to harvest before frost.
For a dedicated fall crop, sow by Aug 11.
Plant Water Budget
Monthly Watering Guide for Mustard Greens
Mustard Greens needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.
| Month | Mustard Greens Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 0.9" | 0" | ❄️ Dormant |
| Feb | — | 0.9" | 0" | ❄️ Dormant |
| Mar | — | 0.7" | 0" | ❄️ Dormant |
| Apr | 3" | 0.5" | 2.5" | 🚿 Regular watering |
| May | 3" | 0.7" | 2.3" | 🚿 Regular watering |
| Jun | 3" | 1.2" | 1.8" | 🚿 Regular watering |
| Jul | 3" | 2" | 1" | 💧 Light watering |
| Aug | 3" | 2.5" | 0.5" | 💧 Light watering |
| Sep | 3" | 2.9" | 0.1" | 💧 Light watering |
| Oct | 3" | 2.6" | 0.4" | 💧 Light watering |
| Nov | — | 1.4" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Petersburg Borough). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Mustard 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.
Mustard Greens Planting Timeline — Petersburg Borough, AK
Mustard Greens 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 | May 28 | May 28 – Jul 30 |
| Fall Sowing | August 11 | Aug 11 – Aug 25 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Harvest |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.7"/week · Only during dry spells
📅 Days to Maturity
30–50 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 7b
📆 Growing Season
180 days in Petersburg Borough
Growing Tips for Mustard Greens in Petersburg Borough
Direct sow Mustard Greens outdoors after April 23 in Petersburg Borough when soil has warmed and frost danger has passed.
Your generous 180.0-day season in Petersburg Borough allows multiple plantings of Mustard Greens. Sow every 15.0 days for continuous harvest.
Common pests for Mustard Greens 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 early spring or fall. Harvest young leaves for milder flavor. Plants bolt quickly in heat so grow as a cool-season crop or provide shade.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Mustard Greens in Other Locations
Frequently Asked Questions
When should I plant Mustard Greens in Petersburg Borough, AK?
Petersburg Borough is in Zone 7b with an average last frost of April 23. Plan your Mustard Greens planting based on this frost date — see the calendar above for exact timing.
What planting zone is Petersburg Borough, AK?
Petersburg Borough, Alaska is in USDA Hardiness Zone 7b. The average last spring frost is April 23 and first fall frost is October 20.
Your Petersburg Borough Garden Planner — Free
A 24-page printable planner built for Petersburg Borough (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.