When to Plant Watercress in Haines Borough, AK
Top priorities for Haines Borough, Alaska gardeners in May
Welcome to May in Zone 5b. These are the moves that will have the biggest impact on your growing season.
-
Set out watercress seedlings
Frost risk is low now in Haines Borough, Alaska. If you've been covering beds overnight, you can stop.
Before June arrives, get these ready
- Starting indoors: watercress
- First harvests: watercress
Watercress is a semi-aquatic plant with a peppery, tangy flavor rich in vitamins and minerals. It grows naturally along streams and can be cultivated in containers with standing water.
Haines Borough, Alaska is in USDA Zone 5b. The average last spring frost is May 7 and the first fall frost is September 29, giving you a growing season of approximately 145 days.
At an elevation of 1,921 feet, Haines Borough receives approximately 57.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 68°F, so choose short-season varieties of Watercress to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Watercress root diseases.
Haines Borough Soil Profile
Soil Type
Silt Loam
Soil pH
4.9-6.4
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 Haines Borough
How your county's soil matches Watercress's growing requirements.
Soil pH
Your soil pH (4.9–6.4) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Haines Borough is excellent for Watercress — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Watercress.
Organic Matter
Organic matter is excellent (6.6%) — Watercress will thrive.
How to Plant Watercress
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Watercress
Sow every 4.6 weeks. Last sowing by Jul 31 to harvest before frost.
For a dedicated fall crop, sow by Jul 21.
Plant Water Budget
Monthly Watering Guide for Watercress
Watercress needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.
| Month | Watercress Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 2.8" | 0" | ❄️ Dormant |
| Feb | — | 2.6" | 0" | ❄️ Dormant |
| Mar | — | 2" | 0" | ❄️ Dormant |
| Apr | — | 2" | 0" | ❄️ Dormant |
| May | 6.5" | 2.7" | 3.8" | 🚿 Regular watering |
| Jun | 6.5" | 4" | 2.5" | 💧 Light watering |
| Jul | 6.5" | 8.1" | 0" | ✅ Rainfall sufficient |
| Aug | 6.5" | 8.5" | 0" | ✅ Rainfall sufficient |
| Sep | 6.5" | 10.6" | 0" | ✅ Rainfall sufficient |
| Oct | — | 6.5" | 0" | ❄️ Dormant |
| Nov | — | 4.1" | 0" | ❄️ Dormant |
| Dec | — | 3.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Haines Borough). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Watercress 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.
Watercress Planting Timeline — Haines Borough, AK
Watercress Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 2 | Apr 2 – Apr 16 |
| Transplant Outdoors | May 7 | May 7 – May 21 |
| Direct Sow | April 23 | Apr 23 – May 14 |
| Harvest | June 18 | Jun 18 – Jul 23 |
| Fall Sowing | July 21 | Jul 21 – Aug 4 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Fall Sowing Harvest |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1.5"/week · Natural rainfall sufficient
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 6.5–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 5b
📆 Growing Season
145 days in Haines Borough
Growing Tips for Watercress in Haines Borough
Direct sow Watercress outdoors after May 07 in Haines Borough when soil has warmed and frost danger has passed.
Common pests for Watercress in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Grow in containers with trays of water kept fresh. Provide partial shade and cool conditions. Harvest stems by cutting above water level. Replace water frequently to prevent stagnation.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Watercress in Other Locations
Frequently Asked Questions
When should I plant Watercress in Haines Borough, AK?
Haines Borough is in Zone 5b with an average last frost of May 7. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.
What planting zone is Haines Borough, AK?
Haines Borough, Alaska is in USDA Hardiness Zone 5b. The average last spring frost is May 7 and first fall frost is September 29.
Your Haines Borough Garden Planner — Free
A 24-page printable planner built for Haines Borough (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.