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When to plant Calendula in Canyon County County,

Canyon County County's spring Calendula window runs March 30 through April 20. most warm-season crops establish quickly once soil holds above 60°F. A second sowing from August 15 to August 29 extends the harvest into fall.

When to Plant Calendula in Canyon County, ID

Canyon County, Idaho Zone 7a June

Top priorities for Canyon County, Idaho gardeners in June

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

Avg. last frost May 4
Avg. first frost October 10
Soil temp (4") 61°F
Watering Critical
Pest pressure High
Daylight 15.2 hrs
  1. Indoor seed-starting week for calendula

    You're about 17 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Pick calendula

    If you can't use it all right away, check the food-preservation section of your planner.

Before July arrives, get these ready
  • 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.

Canyon County, Idaho is in USDA Zone 7a. The average last spring frost is May 4 and the first fall frost is October 10, giving you a growing season of approximately 159 days.

At an elevation of 4,953 feet, Canyon County receives approximately 13.3 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Calendula during the growing season. With low rainfall, drip irrigation is essential for growing Calendula successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Canyon County, ID (Zone 7a) Moderate season
159 days
Last Spring Frost May 4
159 growing days
First Fall Frost October 10
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Canyon County Soil Profile

Soil Type

Loam

Soil pH

6.2-8.2

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (12 days to spare)
Start indoors: Mar 9 Transplant: Apr 20 🌸 Bloom: Jun 8 – Sep 21
Recommended (50%) ✓ Fits season (5 days to spare)
Start indoors: Mar 23 Transplant: May 4 🌸 Bloom: Jun 22 – Oct 5
Safe Start (90%) ✗ May not fit
Start indoors: Apr 25 Transplant: Jun 6 🌸 Bloom: Jul 25 – Nov 7

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 Canyon County

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

Soil pH

Your soil pH (6.2–8.2) is more alkaline than Calendula prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). 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

3
successive plantings in your 159-day season

Sow every 5.7 weeks. Last sowing by Aug 01 to harvest before frost.

For a dedicated fall crop, sow by Aug 15.

Calendula Water Budget

Plant needs
0.5″/week
Rainfall provides
0.4″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 252 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 0.8" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 1.6" 0" ❄️ Dormant
May 2.2" 1.4" 0.8" 💧 Light watering
Jun 2.2" 1.1" 1.1" 🚿 Regular watering
Jul 2.2" 1" 1.2" 🚿 Regular watering
Aug 2.2" 1.6" 0.6" 💧 Light watering
Sep 2.2" 1" 1.2" 🚿 Regular watering
Oct 2.2" 1.1" 1.1" 🚿 Regular watering
Nov 1" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Canyon 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 ~915 GDD — county provides 2,424 GDD Excellent fit

Calendula Planting Timeline — Canyon County, ID

Calendula Planting Calendar

Activity When Date Range
Start Indoors March 23 Mar 23 – Apr 6
Transplant Outdoors May 4 May 4 – May 18
Direct Sow March 30 Mar 30 – Apr 20
Bloom June 22 Jun 22 – Oct 5
Fall Sowing August 15 Aug 15 – Aug 29

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

159 days in Canyon County

Growing Tips for Calendula in Canyon County

Direct sow Calendula outdoors after May 04 in Canyon 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.

Canyon County receives only 13" of rain annually. Calendula needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Canyon County, ID?

Canyon County is in Zone 7a with an average last frost of May 4. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Canyon County, ID?

Canyon County, Idaho is in USDA Hardiness Zone 7a. The average last spring frost is May 4 and first fall frost is October 10.

When should I plant Calendula in Canyon County County, ?

In Canyon County County, , plant Calendula after the last frost (around May 4) and before the first frost (around October 10). Best results when soil holds above 50°F.

What growing zone is Canyon County County, for Calendula?

Canyon County 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 Canyon County County's climate?

Yes — Calendula grows well in Canyon County County's temperate climate. Canyon County County averages a 159-day frost-free season, with last frost around May 4 and first frost around October 10.

🌱

Your Canyon County Garden Planner — Free

A 22-page printable planner built for Canyon 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.

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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 Canyon County, ID. 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.