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When to Plant Crosne in Fairfax County, VA

Fairfax County, Virginia Zone 7b May

This month in Fairfax County, Virginia

We've pulled the most time-sensitive tasks for Fairfax County, Virginia this May and put them front and centre. Tackle them in order.

Avg. last frost April 6
Avg. first frost November 3
Soil temp (4") 67°F
Watering Low
Pest pressure Moderate
Daylight 14.1 hrs

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Crosne (Chinese artichoke) produces small, segmented white tubers with a crunchy texture and mild artichoke-nutty flavor. They are a rare delicacy in French cuisine.

Fairfax County, Virginia is in USDA Zone 7b. The average last spring frost is April 6 and the first fall frost is November 3, giving you a growing season of approximately 211 days.

At an elevation of 548 feet, Fairfax County receives approximately 53 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93°F, providing good warmth for Crosne during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Crosne root diseases.

Fairfax County, VA (Zone 7b) Long season
211 days
Last Spring Frost April 6
211 growing days
First Fall Frost November 3

Fairfax County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Mar 27 🍅 Harvest: Aug 28 – Oct 30
Recommended (50%) ✗ May not fit
Transplant: Apr 6 🍅 Harvest: Sep 7 – Nov 9
Safe Start (90%) ✗ May not fit
Transplant: Apr 25 🍅 Harvest: Sep 26 – Nov 28

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 Fairfax County

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

Soil pH

Your soil pH (5.4–6.5) is more acidic than Crosne prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

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

How to Plant Crosne

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

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

Plant Water Budget

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

Monthly Watering Guide for Crosne

Crosne needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Crosne Needs Rainfall You Supplement Action
Jan 4.1" 0" ❄️ Dormant
Feb 4.6" 0" ❄️ Dormant
Mar 5.5" 0" ❄️ Dormant
Apr 4.3" 4.1" 0.2" 💧 Light watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 5" 0" ✅ Rainfall sufficient
Jul 4.3" 5.9" 0" ✅ Rainfall sufficient
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 3.8" 0.5" 💧 Light watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 4.3" 4.4" 0" ✅ Rainfall sufficient
Dec 4.4" 0" ❄️ Dormant

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

Crosne 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.

Crosne needs ~3,456 GDD — county provides 4,167 GDD Good fit

Crosne Planting Timeline — Fairfax County, VA

Crosne Planting Calendar

Activity When Date Range
Direct Sow March 23 Mar 23 – Apr 13
Harvest August 24 Aug 24 – Oct 26
Fall Sowing August 25 Aug 25 – Sep 8

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

150–200 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7b

📆 Growing Season

211 days in Fairfax County

Growing Tips for Crosne in Fairfax County

Direct sow Crosne outdoors after April 06 in Fairfax County when soil has warmed and frost danger has passed.

Your 211.0-day growing season in Fairfax County is tight for Crosne (150.0-200.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Plant tubers 3 inches deep in spring. Mark the location well as plants die back. Harvest in late fall after frost. Leave some tubers in ground for next year. Very labor-intensive to harvest.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Crosne in Fairfax County, VA?

Fairfax County is in Zone 7b with an average last frost of April 6. Plan your Crosne planting based on this frost date — see the calendar above for exact timing.

What planting zone is Fairfax County, VA?

Fairfax County, Virginia is in USDA Hardiness Zone 7b. The average last spring frost is April 6 and first fall frost is November 3.

🌱

Your Fairfax County Garden Planner — Free

A 24-page printable planner built for Fairfax 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Fairfax County, VA. 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.