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When to plant Calendula in Waldo County County,

Waldo County County's climate puts the Calendula spring window between April 17 and May 8. time plantings around the expected last-frost window for best survival.

When to Plant Calendula in Waldo County, ME

Waldo County, Maine Zone 5b June

Your June game plan for Waldo County, Maine

June is a pivotal month for Waldo County, Maine gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 8
Avg. first frost October 6
Soil temp (4") 68°F
Watering Low
Pest pressure High
Daylight 15.3 hrs
  1. Begin indoor sowing: calendula

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

  2. Pick calendula

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Coming up in July — start thinking about
  • First harvests: calendula

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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.

Waldo County, Maine is in USDA Zone 5b. The average last spring frost is May 8 and the first fall frost is October 6, giving you a growing season of approximately 151 days.

At an elevation of 966 feet, Waldo County receives approximately 46 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Calendula to ensure they mature before fall.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Waldo County, ME (Zone 5b) Moderate season
151 days
Last Spring Frost May 8
151 growing days
First Fall Frost October 6
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Waldo County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.7

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (12 days to spare)
Start indoors: Mar 22 Transplant: May 3 🌸 Bloom: Jun 21 – Sep 20
Recommended (50%) ✓ Fits season (11 days to spare)
Start indoors: Mar 27 Transplant: May 8 🌸 Bloom: Jun 26 – Sep 25
Safe Start (90%) ✓ Fits season (15 days to spare)
Start indoors: Apr 9 Transplant: May 21 🌸 Bloom: Jul 9 – Oct 8

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 Waldo County

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

Soil pH

Your soil pH (4.8–6.7) overlaps with Calendula's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.9%). Annual compost additions will help Calendula.

How to Plant Calendula

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

Succession Planting Calendula

3
successive plantings in your 151-day season

Sow every 5.7 weeks. Last sowing by Jul 28 to harvest before frost.

Calendula Water Budget

Plant needs
0.5″/week
Rainfall provides
1.3″/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 3.1" 0" ❄️ Dormant
Feb 2.7" 0" ❄️ Dormant
Mar 4.4" 0" ❄️ Dormant
Apr 4.1" 0" ❄️ Dormant
May 2.2" 4.8" 0" ✅ Rainfall sufficient
Jun 2.2" 4.1" 0" ✅ Rainfall sufficient
Jul 2.2" 4.3" 0" ✅ Rainfall sufficient
Aug 2.2" 3.7" 0" ✅ Rainfall sufficient
Sep 2.2" 3.6" 0" ✅ Rainfall sufficient
Oct 2.2" 3.6" 0" ✅ Rainfall sufficient
Nov 4" 0" ❄️ Dormant
Dec 3.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Waldo 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 ~780 GDD — county provides 1,963 GDD Excellent fit

Calendula Planting Timeline — Waldo County, ME

Calendula Planting Calendar

Activity When Date Range
Start Indoors March 27 Mar 27 – Apr 10
Transplant Outdoors May 8 May 8 – May 22
Direct Sow April 17 Apr 17 – May 8
Bloom June 26 Jun 26 – Sep 25

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June Bloom
July Bloom
August Bloom
September Bloom
October
November
December
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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 5b

📆 Growing Season

151 days in Waldo County

Growing Tips for Calendula in Waldo County

Direct sow Calendula outdoors after May 08 in Waldo 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 Waldo County, ME?

Waldo County is in Zone 5b with an average last frost of May 8. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Waldo County, ME?

Waldo County, Maine is in USDA Hardiness Zone 5b. The average last spring frost is May 8 and first fall frost is October 6.

When should I plant Calendula in Waldo County, ?

In Waldo County, , plant Calendula after the last frost (around May 8) and before the first frost (around October 6). Best results when soil holds above 50°F.

What growing zone is Waldo County, for Calendula?

Waldo County sits in USDA Zone 5b. Calendula grows reliably in zones 2a through 11b, so it's a good fit here.

Can Calendula grow in Waldo County's climate?

Yes — Calendula grows well in Waldo County's temperate climate. Waldo County averages a 151-day frost-free season, with last frost around May 8 and first frost around October 6.

🌱

Your Waldo County Garden Planner — Free

A 22-page printable planner built for Waldo County (Zone 5b). 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 Waldo County, ME. 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.