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When to plant Borage in Calvert County, MD

Calvert County sits in USDA Zone 7b. Plant Borage between March 16 (after last frost on March 30) and April 6. A second sowing from September 1 to September 15 extends the harvest into fall.

When to Plant Borage in Calvert County, MD

Calvert County, Maryland Zone 7b July

July in Calvert County, Maryland — your action list

A quick July briefing for Calvert County, Maryland gardeners — what's urgent, what's next, and what can wait.

Avg. last frost March 30
Avg. first frost November 10
Soil temp (4") 87°F
Watering Low
Pest pressure High
Daylight 14.4 hrs
  1. Collect borage at their peak

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

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Borage is a self-seeding annual herb with star-shaped blue flowers that attract pollinators. Its leaves have a cucumber-like flavor and the flowers are edible.

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 Borage 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

Borage Planting Risk Windows

Early Start (70% safe) ✓ Fits season (124 days to spare)
Start indoors: Feb 19 Transplant: Mar 19 🍅 Harvest: May 14 – Jul 2
Recommended (50%) ✓ Fits season (127 days to spare)
Start indoors: Feb 23 Transplant: Mar 23 🍅 Harvest: May 18 – Jul 6
Safe Start (90%) ✓ Fits season (138 days to spare)
Start indoors: Mar 13 Transplant: Apr 10 🍅 Harvest: Jun 5 – Jul 24

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 Borage's growing requirements.

Soil pH

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

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Borage.

How to Plant Borage

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

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

Succession Planting Borage

5
successive plantings in your 225-day season

Sow every 5.7 weeks. Last sowing by Sep 11 to harvest before frost.

For a dedicated fall crop, sow by Sep 01.

Borage Water Budget

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

Monthly Watering Guide for Borage

Borage needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Borage Needs Rainfall You Supplement Action
Jan 3.2" 0" ❄️ Dormant
Feb 3.4" 0" ❄️ Dormant
Mar 2.2" 3.6" 0" ✅ Rainfall sufficient
Apr 2.2" 3.8" 0" ✅ Rainfall sufficient
May 2.2" 4.1" 0" ✅ Rainfall sufficient
Jun 2.2" 4.5" 0" ✅ Rainfall sufficient
Jul 2.2" 5.1" 0" ✅ Rainfall sufficient
Aug 2.2" 3.9" 0" ✅ Rainfall sufficient
Sep 2.2" 4" 0" ✅ Rainfall sufficient
Oct 2.2" 4.2" 0" ✅ Rainfall sufficient
Nov 2.2" 3.2" 0" ✅ Rainfall sufficient
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.

Borage 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.

Borage needs ~962 GDD — county provides 3,937 GDD Excellent fit

Borage Planting Timeline — Calvert County, MD

Borage Planting Calendar

Activity When Date Range
Start Indoors February 23 Feb 23 – Mar 9
Transplant Outdoors March 23 Mar 23 – Apr 6
Direct Sow March 16 Mar 16 – Apr 6
Harvest May 18 May 18 – Jul 6
Fall Sowing September 1 Sep 1 – Sep 15

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

50–60 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

225 days in Calvert County

Growing Tips for Borage in Calvert County

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

General growing tips

Direct sow in spring as borage does not transplant well. Allow some plants to go to seed for next year. Young leaves are best; older leaves become bristly.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Borage in Calvert County, MD?

Calvert County is in Zone 7b with an average last frost of March 30. Plan your Borage 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.

When should I plant Borage in Calvert County, MD?

In Calvert County, MD, plant Borage after the last frost (around March 30) and before the first frost (around November 10). Best results when soil holds above 50°F.

What growing zone is Calvert County, MD for Borage?

Calvert County sits in USDA Zone 7b. Borage grows reliably in zones 3a through 11b, so it's a good fit here.

Can Borage grow in Calvert County's climate?

Yes — Borage grows well in Calvert County's temperate climate. Calvert County averages a 225-day frost-free season, with last frost around March 30 and first frost around November 10.

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Your Calvert County Garden Planner — Free

A 22-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.

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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 Calvert County, MD. Local conditions may vary. Last updated: July 2026.

Sources & credits

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