When to plant Nasturtium in Petersburg Borough County,
For Nasturtium in Petersburg Borough County, the safe spring window opens around April 23 and closes around May 14. Last expected frost is April 23, first fall frost October 20, giving a 180-day growing season.
When to Plant Nasturtium in Petersburg Borough, AK
June in Petersburg Borough, Alaska — your action list
A quick June briefing for Petersburg Borough, Alaska gardeners — what's urgent, what's next, and what can wait.
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Collect nasturtium at their peak
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
July will be here before you know it — start on
- First harvests: nasturtium
Nasturtium (Tropaeolum majus) is a fast-growing annual with distinctive round, lily-pad leaves and bold trumpet-shaped blooms in warm oranges, reds, and yellows. Both the flowers and leaves are edible with a peppery watercress flavor. Planted near vegetables, nasturtiums act as a sacrifice trap-crop, luring aphids away from more valuable plants. They thrive in poor, dry soil — rich conditions produce lush foliage but few flowers.
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 Nasturtium to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Nasturtium successfully. Mulch heavily to conserve soil moisture.
Petersburg Borough Soil Profile
Soil Type
Silt Loam
Soil pH
4.9-6.3
Drainage
Well Drained
Nasturtium 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 Nasturtium's growing requirements.
Soil pH
Your soil pH (4.9–6.3) is more acidic than Nasturtium prefers (6.0–8.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Petersburg Borough is excellent for Nasturtium — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Nasturtium prefers dry conditions but your soil drains poorly. Use raised beds or mounded rows to prevent root rot.
Organic Matter
Organic matter is excellent (6.8%) — Nasturtium will thrive.
How to Plant Nasturtium
Succession Planting Nasturtium
Sow every 6.3 weeks. Last sowing by Aug 16 to harvest before frost.
Nasturtium Water Budget
Monthly Watering Guide for Nasturtium
Nasturtium needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Nasturtium Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 0.9" | 0" | ❄️ Dormant |
| Feb | — | 0.9" | 0" | ❄️ Dormant |
| Mar | — | 0.7" | 0" | ❄️ Dormant |
| Apr | 2.2" | 0.5" | 1.7" | 🚿 Regular watering |
| May | 2.2" | 0.7" | 1.5" | 🚿 Regular watering |
| Jun | 2.2" | 1.2" | 1" | 💧 Light watering |
| Jul | 2.2" | 2" | 0.2" | 💧 Light watering |
| Aug | 2.2" | 2.5" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.6" | 0" | ✅ Rainfall sufficient |
| 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.
Nasturtium 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.
Nasturtium Planting Timeline — Petersburg Borough, AK
Nasturtium Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 26 | Mar 26 – Apr 9 |
| Transplant Outdoors | April 23 | Apr 23 – May 7 |
| Direct Sow | April 23 | Apr 23 – May 14 |
| Bloom | June 18 | Jun 18 – Nov 5 |
Plant 0.5" deep · 10" 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 Direct Sow |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | Bloom |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
55–65 days
🧪 Soil pH
Needs 6–8 · Your soil: too_acidic
🗺️ USDA Zone
Zone 7b
📆 Growing Season
180 days in Petersburg Borough
Growing Tips for Nasturtium in Petersburg Borough
Direct sow Nasturtium outdoors after April 23 in Petersburg Borough when soil has warmed and frost danger has passed.
Petersburg Borough receives only 17" of rain annually. Nasturtium needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Direct-sow large seeds 1/2 inch deep after last frost; soak seeds overnight to speed germination (7-10 days). Nasturtiums dislike root disturbance so direct sowing is strongly preferred. Avoid fertilizing — poor soil brings the best bloom. Trailing types can cover banks and climb trellises; dwarf types suit containers. In hot climates (zones 9+) plant in fall for winter/spring bloom as plants struggle in peak summer heat.
Companion Planting
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Nasturtium in Other Locations
Frequently Asked Questions
When should I plant Nasturtium in Petersburg Borough, AK?
Petersburg Borough is in Zone 7b with an average last frost of April 23. Plan your Nasturtium 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.
When should I plant Nasturtium in Petersburg Borough County, ?
In Petersburg Borough County, , plant Nasturtium after the last frost (around April 23) and before the first frost (around October 20). Best results when soil holds above 50°F.
What growing zone is Petersburg Borough County, for Nasturtium?
Petersburg Borough County sits in USDA Zone 7b. Nasturtium grows reliably in zones 2a through 11b, so it's a good fit here.
Can Nasturtium grow in Petersburg Borough County's climate?
Yes — Nasturtium grows well in Petersburg Borough County's temperate climate. Petersburg Borough County averages a 180-day frost-free season, with last frost around April 23 and first frost around October 20.
Your Petersburg Borough Garden Planner — Free
A 22-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.