When to Plant Kale in Grand Isle County, VT
What to do in April
Welcome to April in Zone 4b. These are the moves that will have the biggest impact on your growing season.
-
Plant kale from seed, right in the garden
Your soil is 40°F — warm enough for these to germinate without babying.
To set up a strong May, finish these tasks
- Transplants going out: kale
Kale is an exceptionally hardy, nutrient-dense green available in curly, lacinato, and Russian varieties. It tolerates heavy frost and often tastes sweeter after cold exposure.
Grand Isle County, Vermont is in USDA Zone 4b. The average last spring frost is May 6 and the first fall frost is October 10, giving you a growing season of approximately 157 days.
At an elevation of 1,011 feet, Grand Isle County receives approximately 38.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Kale to ensure they mature before fall.
Grand Isle County Soil Profile
Soil Type
Silt Loam
Soil pH
4.8-6.4
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 Grand Isle County
How your county's soil matches Kale's growing requirements.
Soil pH
Your soil pH (4.8–6.4) is more acidic than Kale prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Grand Isle County is excellent for Kale — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.7%). Annual compost additions will help Kale.
How to Plant Kale
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Kale
Sow every 5.7 weeks. Last sowing by Aug 01 to harvest before frost.
For a dedicated fall crop, sow by Jul 18.
Plant Water Budget
Monthly Watering Guide for Kale
Kale needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.
| Month | Kale Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 2.5" | 0" | ❄️ Dormant |
| Feb | — | 2.5" | 0" | ❄️ Dormant |
| Mar | — | 3.2" | 0" | ❄️ Dormant |
| Apr | — | 3.1" | 0" | ❄️ Dormant |
| May | 3.5" | 3.6" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 3.5" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 3.5" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 3.6" | 0" | ✅ Rainfall sufficient |
| Oct | 3.5" | 2.8" | 0.7" | 💧 Light watering |
| Nov | — | 3.2" | 0" | ❄️ Dormant |
| Dec | — | 2.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Grand Isle County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Kale 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.
Kale Planting Timeline — Grand Isle County, VT
Kale Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 25 | Mar 25 – Apr 8 |
| Transplant Outdoors | May 6 | May 6 – May 20 |
| Direct Sow | April 29 | Apr 29 – May 20 |
| Harvest | July 1 | Jul 1 – Aug 26 |
| Fall Sowing | July 18 | Jul 18 – Aug 1 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Fall Sowing Harvest |
| August | Fall Sowing Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · Natural rainfall sufficient
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 4b
📆 Growing Season
157 days in Grand Isle County
Growing Tips for Kale in Grand Isle County
Direct sow Kale outdoors after May 06 in Grand Isle County when soil has warmed and frost danger has passed.
Common pests for Kale 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 or transplant in early spring or late summer. Harvest outer leaves first to keep plants productive. Kale overwinters in many climates and can provide greens all year.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 1/2 mile from other brassicas (broccoli, cabbage, etc.) — they all cross.
Kale in Other Locations
Frequently Asked Questions
When should I plant Kale in Grand Isle County, VT?
Grand Isle County is in Zone 4b with an average last frost of May 6. Plan your Kale planting based on this frost date — see the calendar above for exact timing.
What planting zone is Grand Isle County, VT?
Grand Isle County, Vermont is in USDA Hardiness Zone 4b. The average last spring frost is May 6 and first fall frost is October 10.
Your Grand Isle County Garden Planner — Free
A 24-page printable planner built for Grand Isle County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.