When to Plant Sorrel in Petersburg Borough, AK
What to do in May
Here's what deserves your attention in Petersburg Borough, Alaska this month. Everything below is tailored to Zone 7b and timed around your local frost dates.
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Start sorrel indoors
These need a head start before your last frost (April 23). Sow into cells now so you're ready to transplant in a few weeks.
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Collect sorrel at their peak
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: sorrel
Sorrel is a perennial herb with tangy, lemon-flavored arrow-shaped leaves. It is one of the first greens to emerge in spring and is used in soups and 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 Sorrel to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Sorrel 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 Sorrel's growing requirements.
Soil pH
Your soil pH (4.9–6.3) overlaps with Sorrel's range (5.5–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Petersburg Borough is excellent for Sorrel — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Sorrel.
Organic Matter
Organic matter is excellent (6.8%) — Sorrel will thrive.
How to Plant Sorrel
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Sorrel
Sow every 4.6 weeks. Last sowing by Aug 21 to harvest before frost.
For a dedicated fall crop, sow by Aug 11.
Plant Water Budget
Monthly Watering Guide for Sorrel
Sorrel needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Sorrel Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 0.9" | 0" | ❄️ Dormant |
| Feb | — | 0.9" | 0" | ❄️ Dormant |
| Mar | — | 0.7" | 0" | ❄️ Dormant |
| Apr | 4.3" | 0.5" | 3.8" | 🚿 Regular watering |
| May | 4.3" | 0.7" | 3.6" | 🚿 Regular watering |
| Jun | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| Jul | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Aug | 4.3" | 2.5" | 1.8" | 💧 Light watering |
| Sep | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Oct | 4.3" | 2.6" | 1.7" | 💧 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.
Sorrel 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.
Sorrel Planting Timeline — Petersburg Borough, AK
Sorrel Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 19 | Mar 19 – Apr 2 |
| Transplant Outdoors | April 16 | Apr 16 – Apr 30 |
| 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 · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 5.5–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 7b
📆 Growing Season
180 days in Petersburg Borough
Growing Tips for Sorrel in Petersburg Borough
Direct sow Sorrel 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 Sorrel. Sow every 20.0 days for continuous harvest.
Petersburg Borough receives only 17" of rain annually. Sorrel needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Direct sow in early spring or fall. Remove flower stalks promptly to encourage leaf production. Divide clumps every 3-4 years. Young leaves have the best flavor.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Sorrel in Other Locations
Frequently Asked Questions
When should I plant Sorrel in Petersburg Borough, AK?
Petersburg Borough is in Zone 7b with an average last frost of April 23. Plan your Sorrel 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.