When to Plant Purslane in Kalawao County, HI
Your April game plan for Kalawao County, Hawaii
If you only do a handful of things in the garden this April, make it these. They're sequenced around your zone's frost timing.
Purslane is a succulent edible plant rich in omega-3 fatty acids, often considered a weed but increasingly valued as a nutritious green. It has a lemony, peppery flavor.
Kalawao County, Hawaii is in USDA Zone 11a. The average last spring frost is January 1 and the first fall frost is December 31, giving you a growing season of approximately 364 days.
At an elevation of 402 feet, Kalawao County receives approximately 28.4 inches of rainfall annually with predominantly silty clay soil. Summer highs average 85°F, providing good warmth for Purslane during the growing season. Clay soil retains moisture well for Purslane, but amend with compost to improve drainage and prevent root rot.
Kalawao County Soil Profile
Soil Type
Silty Clay
Soil pH
5.7-6.7
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 Kalawao County
How your county's soil matches Purslane's growing requirements.
Soil pH
Your soil pH (5.7–6.7) is within Purslane's preferred range (5.5–7.5).
Soil Texture
Your silty clay soil in Kalawao County is workable for Purslane. Add compost annually to improve structure.
Organic Matter
Organic matter is moderate (3.9%). Annual compost additions will help Purslane.
How to Plant Purslane
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Purslane
Purslane 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 | Purslane Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | 2.2" | 4.1" | 0" | ✅ Rainfall sufficient |
| Feb | 2.2" | 3.1" | 0" | ✅ Rainfall sufficient |
| Mar | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 2.6" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 1.6" | 0.6" | 💧 Light watering |
| Jun | 2.2" | 0.9" | 1.3" | 🚿 Regular watering |
| Jul | 2.2" | 0.7" | 1.5" | 🚿 Regular watering |
| Aug | 2.2" | 0.9" | 1.3" | 🚿 Regular watering |
| Sep | 2.2" | 1.4" | 0.8" | 💧 Light watering |
| Oct | 2.2" | 2.8" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| Dec | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
Water needs are for active growing months only (Jan–Dec in Kalawao County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Purslane 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.
Purslane Planting Timeline — Kalawao County, HI
Purslane Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 4 | Dec 4 – Dec 18 |
| Transplant Outdoors | January 1 | Jan 1 – Jan 15 |
| Direct Sow | December 11 | Dec 11 – Jan 1 |
| Harvest | February 12 | Feb 12 – Mar 19 |
| Fall Sowing | November 5 | Nov 5 – Nov 19 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Transplant Outdoors Direct Sow |
| February | Harvest |
| March | Harvest |
| April | — |
| May | — |
| June | — |
| July | — |
| August | — |
| September | — |
| October | — |
| November | Fall Sowing |
| December | Start Indoors Direct Sow |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Only during dry spells
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 5.5–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 11a
📆 Growing Season
364 days in Kalawao County
Growing Tips for Purslane in Kalawao County
With Kalawao County's clay soil (37% clay), work in 3-4 inches of compost before planting Purslane. Avoid tilling when soil is wet to prevent compaction.
Your generous 365.0-day season in Kalawao County allows multiple plantings of Purslane. Sow every 20.0 days for continuous harvest.
General growing tips
Direct sow after last frost or allow to self-seed. Purslane thrives in hot, dry conditions. Harvest stem tips regularly. Contains more omega-3 fatty acids than any other leafy green.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Purslane in Other Locations
Frequently Asked Questions
When should I plant Purslane in Kalawao County, HI?
Kalawao County is in Zone 11a with an average last frost of January 1. Plan your Purslane planting based on this frost date — see the calendar above for exact timing.
What planting zone is Kalawao County, HI?
Kalawao County, Hawaii is in USDA Hardiness Zone 11a. The average last spring frost is January 1 and first fall frost is December 31.
Your Kalawao County Garden Planner — Free
A 24-page printable planner built for Kalawao County (Zone 11a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.