When to Plant Kai Lan in Hillsborough County, NH
Top priorities for Hillsborough County, New Hampshire gardeners in May
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
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Move kai lan from tray to bed
Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.
To set up a strong June, finish these tasks
- Starting indoors: kai lan
- First harvests: kai lan
Kai lan (Chinese broccoli) is a brassica grown for its thick, glossy stems and small flower buds. It has a slightly bitter, broccoli-like flavor essential in Cantonese cooking.
Hillsborough County, New Hampshire is in USDA Zone 6a. The average last spring frost is May 2 and the first fall frost is October 11, giving you a growing season of approximately 162 days.
At an elevation of 145 feet, Hillsborough County receives approximately 44 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Kai Lan to ensure they mature before fall.
Hillsborough County Soil Profile
Soil Type
Silt Loam
Soil pH
4.9-6.6
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 Hillsborough County
How your county's soil matches Kai Lan's growing requirements.
Soil pH
Your soil pH (4.9–6.6) is more acidic than Kai Lan prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Hillsborough County is excellent for Kai Lan — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Kai Lan.
Organic Matter
Organic matter is moderate (3.9%). Annual compost additions will help Kai Lan.
How to Plant Kai Lan
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Kai Lan
Sow every 5.1 weeks. Last sowing by Aug 12 to harvest before frost.
For a dedicated fall crop, sow by Aug 02.
Plant Water Budget
Monthly Watering Guide for Kai Lan
Kai Lan needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Kai Lan Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3" | 0" | ❄️ Dormant |
| Feb | — | 2.7" | 0" | ❄️ Dormant |
| Mar | — | 3.8" | 0" | ❄️ Dormant |
| Apr | — | 4.4" | 0" | ❄️ Dormant |
| May | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Jun | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Jul | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Sep | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Oct | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Nov | — | 3.2" | 0" | ❄️ Dormant |
| Dec | — | 3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Hillsborough County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Kai Lan 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.
Kai Lan Planting Timeline — Hillsborough County, NH
Kai Lan Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 28 | Mar 28 – Apr 11 |
| Transplant Outdoors | May 2 | May 2 – May 16 |
| Direct Sow | April 18 | Apr 18 – May 9 |
| Harvest | June 20 | Jun 20 – Jul 18 |
| Fall Sowing | August 2 | Aug 2 – Aug 16 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
45–60 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 6a
📆 Growing Season
162 days in Hillsborough County
Growing Tips for Kai Lan in Hillsborough County
Direct sow Kai Lan outdoors after May 02 in Hillsborough County when soil has warmed and frost danger has passed.
Your generous 162.0-day season in Hillsborough County allows multiple plantings of Kai Lan. Sow every 22.0 days for continuous harvest.
Common pests for Kai Lan 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 in spring or fall. Harvest when flower buds first appear but before they open. Cut stems at the base to encourage side shoots. Prefers cool weather.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Kai Lan in Other Locations
Frequently Asked Questions
When should I plant Kai Lan in Hillsborough County, NH?
Hillsborough County is in Zone 6a with an average last frost of May 2. Plan your Kai Lan planting based on this frost date — see the calendar above for exact timing.
What planting zone is Hillsborough County, NH?
Hillsborough County, New Hampshire is in USDA Hardiness Zone 6a. The average last spring frost is May 2 and first fall frost is October 11.
Your Hillsborough County Garden Planner — Free
A 24-page printable planner built for Hillsborough County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.