Blog

When to plant Calendula in Frederick County, MD

Frederick County gardeners should plant Calendula between March 12 and April 2 in spring. With Frederick County's Zone 7a climate (last frost April 16), Calendula needs 50–70 days to mature — plant by August 14 for a full harvest. A second sowing from August 28 to September 11 extends the harvest into fall.

When to Plant Calendula in Frederick County, MD

Frederick County, Maryland Zone 7a June

This month in Frederick County, Maryland

Welcome to June in Zone 7a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 16
Avg. first frost October 23
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 14.8 hrs
  1. Pick calendula

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Get ahead of July
  • First harvests: calendula

Instant PDF download. No spam, unsubscribe any time.

Calendula (Calendula officinalis) is a cheerful, edible-flowered cool-season annual valued by herbalists, chefs, and gardeners alike. Its golden-orange petals are used in salves, teas, and as a saffron substitute. Hardy enough to tolerate light frosts, it blooms prolifically in spring and fall, taking a pause during the hottest weeks of summer.

Frederick County, Maryland is in USDA Zone 7a. The average last spring frost is April 16 and the first fall frost is October 23, giving you a growing season of approximately 190 days.

At an elevation of 756 feet, Frederick County receives approximately 49.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Calendula during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Frederick County, MD (Zone 7a) Moderate season
190 days
Last Spring Frost April 16
190 growing days
First Fall Frost October 23

Frederick County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.8

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (34 days to spare)
Start indoors: Mar 1 Transplant: Apr 12 🌸 Bloom: May 31 – Sep 13
Recommended (50%) ✓ Fits season (36 days to spare)
Start indoors: Mar 5 Transplant: Apr 16 🌸 Bloom: Jun 4 – Sep 17
Safe Start (90%) ✓ Fits season (23 days to spare)
Start indoors: Mar 29 Transplant: May 10 🌸 Bloom: Jun 28 – Oct 11

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 Frederick County

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

Soil pH

Your soil pH (5.3–6.8) overlaps with Calendula's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Drainage

Calendula prefers dry conditions but your soil drains poorly. Use raised beds or mounded rows to prevent root rot.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Calendula.

How to Plant Calendula

0.3"
Planting Depth
9"
Between Plants
12"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Calendula

4
successive plantings in your 190-day season

Sow every 5.7 weeks. Last sowing by Aug 14 to harvest before frost.

For a dedicated fall crop, sow by Aug 28.

Calendula Water Budget

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

Monthly Watering Guide for Calendula

Calendula 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 Calendula Needs Rainfall You Supplement Action
Jan 3.3" 0" ❄️ Dormant
Feb 3" 0" ❄️ Dormant
Mar 3.8" 0" ❄️ Dormant
Apr 2.2" 4.9" 0" ✅ Rainfall sufficient
May 2.2" 4" 0" ✅ Rainfall sufficient
Jun 2.2" 4.1" 0" ✅ Rainfall sufficient
Jul 2.2" 5.7" 0" ✅ Rainfall sufficient
Aug 2.2" 4" 0" ✅ Rainfall sufficient
Sep 2.2" 4.4" 0" ✅ Rainfall sufficient
Oct 2.2" 4" 0" ✅ Rainfall sufficient
Nov 4.1" 0" ❄️ Dormant
Dec 4.2" 0" ❄️ Dormant

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

Calendula 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.

Calendula needs ~1,005 GDD — county provides 3,182 GDD Excellent fit

Calendula Planting Timeline — Frederick County, MD

Calendula Planting Calendar

Activity When Date Range
Start Indoors March 5 Mar 5 – Mar 19
Transplant Outdoors April 16 Apr 16 – Apr 30
Direct Sow March 12 Mar 12 – Apr 2
Bloom June 4 Jun 4 – Sep 17
Fall Sowing August 28 Aug 28 – Sep 11

Plant 0.3" deep · 9" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

190 days in Frederick County

Growing Tips for Calendula in Frederick County

Direct sow Calendula outdoors after April 16 in Frederick County when soil has warmed and frost danger has passed.

Common pests for Calendula in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct-sow in early spring as soon as soil can be worked — seeds germinate in cool soil (50-65°F). In zones 7+, also sow in fall for winter/spring bloom. Deadhead consistently to extend bloom. Plants self-seed readily; save a few spent heads and allow them to drop. Harvest petals when flowers are fully open for best flavor and medicinal value.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Calendula in Frederick County, MD?

Frederick County is in Zone 7a with an average last frost of April 16. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Frederick County, MD?

Frederick County, Maryland is in USDA Hardiness Zone 7a. The average last spring frost is April 16 and first fall frost is October 23.

When should I plant Calendula in Frederick County, MD?

In Frederick County, MD, plant Calendula after the last frost (around April 16) and before the first frost (around October 23). Best results when soil holds above 50°F.

What growing zone is Frederick County, MD for Calendula?

Frederick County sits in USDA Zone 7a. Calendula grows reliably in zones 2a through 11b, so it's a good fit here.

Can Calendula grow in Frederick County's climate?

Yes — Calendula grows well in Frederick County's temperate climate. Frederick County averages a 190-day frost-free season, with last frost around April 16 and first frost around October 23.

🌱

Your Frederick County Garden Planner — Free

A 22-page printable planner built for Frederick County (Zone 7a). 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 Frederick County, MD. Local conditions may vary. Last updated: June 2026.

Sources & credits

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