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When to Plant Crosne in Calvert County, MD

Calvert County, Maryland Zone 7b May

What to do 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.

Avg. last frost March 30
Avg. first frost November 10
Soil temp (4") 68°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.

Calvert County, Maryland is in USDA Zone 7b. The average last spring frost is March 30 and the first fall frost is November 10, giving you a growing season of approximately 225 days.

At an elevation of 539 feet, Calvert County receives approximately 46.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Crosne during the growing season.

Calvert County, MD (Zone 7b) Long season
225 days
Last Spring Frost March 30
225 growing days
First Fall Frost November 10

Calvert County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (5 days to spare)
Transplant: Mar 26 🍅 Harvest: Aug 27 – Oct 29
Recommended (50%) ✓ Fits season (8 days to spare)
Transplant: Mar 30 🍅 Harvest: Aug 31 – Nov 2
Safe Start (90%) ✓ Fits season (19 days to spare)
Transplant: Apr 17 🍅 Harvest: Sep 18 – Nov 20

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 Calvert County

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

Soil pH

Your soil pH (5.5–6.9) overlaps with Crosne's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). 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
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 279 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 3.2" 0" ❄️ Dormant
Feb 3.4" 0" ❄️ Dormant
Mar 4.3" 3.6" 0.7" 💧 Light watering
Apr 4.3" 3.8" 0.5" 💧 Light watering
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 5.1" 0" ✅ Rainfall sufficient
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 4" 0.3" 💧 Light watering
Oct 4.3" 4.2" 0.1" 💧 Light watering
Nov 4.3" 3.2" 1.1" 💧 Light watering
Dec 3.1" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Calvert 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 ~3,062 GDD — county provides 3,937 GDD Good fit

Crosne Planting Timeline — Calvert County, MD

Crosne Planting Calendar

Activity When Date Range
Direct Sow March 16 Mar 16 – Apr 6
Harvest August 17 Aug 17 – Oct 19
Fall Sowing September 1 Sep 1 – Sep 15

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 Harvest
September Fall Sowing Harvest
October Harvest
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

150–200 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

225 days in Calvert County

Growing Tips for Crosne in Calvert County

Direct sow Crosne outdoors after March 30 in Calvert County when soil has warmed and frost danger has passed.

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 Calvert County, MD?

Calvert County is in Zone 7b with an average last frost of March 30. Plan your Crosne planting based on this frost date — see the calendar above for exact timing.

What planting zone is Calvert County, MD?

Calvert County, Maryland is in USDA Hardiness Zone 7b. The average last spring frost is March 30 and first fall frost is November 10.

🌱

Your Calvert County Garden Planner — Free

A 24-page printable planner built for Calvert 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 Calvert County, MD. 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.