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When to Plant Kohlrabi in Sussex County, DE

Sussex County, Delaware Zone 7b May

Sussex County, Delaware gardeners: here's your May plan

Your garden in Sussex County, Delaware is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 3
Avg. first frost November 7
Soil temp (4") 68°F
Watering Low
Pest pressure Moderate
Daylight 14.1 hrs
  1. Indoor seed-starting week for kohlrabi

    A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.

  2. Bring in the kohlrabi

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

June prep starts now
  • First harvests: kohlrabi

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Kohlrabi is an unusual brassica that forms a swollen stem above ground with a mild, sweet turnip-like flavor. Both the bulb and tender leaves are edible.

Sussex County, Delaware is in USDA Zone 7b. The average last spring frost is April 3 and the first fall frost is November 7, giving you a growing season of approximately 218 days.

At an elevation of 1,090 feet, Sussex County receives approximately 46 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Kohlrabi during the growing season.

Sussex County, DE (Zone 7b) Long season
218 days
Last Spring Frost April 3
218 growing days
First Fall Frost November 7

Sussex County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (136 days to spare)
Start indoors: Feb 20 Transplant: Mar 27 🍅 Harvest: May 15 – Jun 19
Recommended (50%) ✓ Fits season (134 days to spare)
Start indoors: Feb 27 Transplant: Apr 3 🍅 Harvest: May 22 – Jun 26
Safe Start (90%) ✓ Fits season (126 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: Jun 10 – Jul 15

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 Sussex County

How your county's soil matches Kohlrabi's growing requirements.

Soil pH

Your soil pH (5.6–6.5) overlaps with Kohlrabi's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Sussex County is excellent for Kohlrabi — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Kohlrabi.

How to Plant Kohlrabi

0.5"
Planting Depth
4"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Kohlrabi

5
successive plantings in your 218-day season

Sow every 5.1 weeks. Last sowing by Sep 03 to harvest before frost.

For a dedicated fall crop, sow by Aug 29.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Kohlrabi

Kohlrabi needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Kohlrabi Needs Rainfall You Supplement Action
Jan 3.5" 0" ❄️ Dormant
Feb 3.5" 0" ❄️ Dormant
Mar 3.9" 0" ❄️ Dormant
Apr 3" 3.7" 0" ✅ Rainfall sufficient
May 3" 4.5" 0" ✅ Rainfall sufficient
Jun 3" 3.7" 0" ✅ Rainfall sufficient
Jul 3" 5.3" 0" ✅ Rainfall sufficient
Aug 3" 4.1" 0" ✅ Rainfall sufficient
Sep 3" 3.9" 0" ✅ Rainfall sufficient
Oct 3" 3.4" 0" ✅ Rainfall sufficient
Nov 3" 3.2" 0" ✅ Rainfall sufficient
Dec 3.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Sussex County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Kohlrabi 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.

Kohlrabi needs ~880 GDD — county provides 3,488 GDD Excellent fit

Kohlrabi Planting Timeline — Sussex County, DE

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors February 27 Feb 27 – Mar 13
Transplant Outdoors April 3 Apr 3 – Apr 17
Direct Sow March 20 Mar 20 – Apr 10
Harvest May 22 May 22 – Jun 26
Fall Sowing August 29 Aug 29 – Sep 12

Plant 0.5" deep · 4" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May Harvest
June Harvest
July
August Fall Sowing
September Fall Sowing
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

45–65 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

218 days in Sussex County

Growing Tips for Kohlrabi in Sussex County

Direct sow Kohlrabi outdoors after April 03 in Sussex County when soil has warmed and frost danger has passed.

Your generous 218.0-day season in Sussex County allows multiple plantings of Kohlrabi. Sow every 22.0 days for continuous harvest.

Common pests for Kohlrabi 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 bulbs are 2-3 inches in diameter for best texture and flavor. Larger bulbs may become woody and fibrous.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Kohlrabi in Sussex County, DE?

Sussex County is in Zone 7b with an average last frost of April 3. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sussex County, DE?

Sussex County, Delaware is in USDA Hardiness Zone 7b. The average last spring frost is April 3 and first fall frost is November 7.

🌱

Your Sussex County Garden Planner — Free

A 24-page printable planner built for Sussex County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Sussex County, DE. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.