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When to Plant Calendula in Humboldt County, NV

Humboldt County, Nevada Zone 6b June

June in the garden — Humboldt County, Nevada

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 30
Avg. first frost September 15
Soil temp (4") 53°F
Watering Critical
Pest pressure High
Daylight 14.9 hrs
Coming up in July — start thinking about
  • Starting indoors: calendula
  • 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.

Humboldt County, Nevada is in USDA Zone 6b. The average last spring frost is May 30 and the first fall frost is September 15, giving you a growing season of approximately 108 days.

At an elevation of 5,527 feet, Humboldt County receives approximately 8.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 94°F, providing good warmth for Calendula during the growing season. Sandy soil warms quickly in spring — great for early planting — but Calendula will need more frequent watering and organic matter to retain nutrients. 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
Humboldt County, NV (Zone 6b) Short season
108 days
Last Spring Frost May 30
108 growing days
First Fall Frost September 15
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Humboldt County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.6

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 10 Transplant: May 22 🌸 Bloom: Jul 10 – Oct 16
Recommended (50%) ✗ May not fit
Start indoors: Apr 18 Transplant: May 30 🌸 Bloom: Jul 18 – Oct 24
Safe Start (90%) ✗ May not fit
Start indoors: May 7 Transplant: Jun 18 🌸 Bloom: Aug 6 – Nov 12

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 Humboldt County

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

Soil pH

Your soil pH (7.2–8.6) is more alkaline than Calendula prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Humboldt County warms quickly in spring but drains fast. Calendula will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Calendula.

Organic Matter

Organic matter is low (0.9%). Add 2-3 inches of compost before planting Calendula.

How to Plant Calendula

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

Succession Planting Calendula

2
successive plantings in your 108-day season

Sow every 5.7 weeks. Last sowing by Jul 07 to harvest before frost.

Calendula Water Budget

Plant needs
0.5″/week
Rainfall provides
0.3″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 382 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 0.6" 0" ❄️ Dormant
Feb 0.5" 0" ❄️ Dormant
Mar 0.4" 0" ❄️ Dormant
Apr 0.3" 0" ❄️ Dormant
May 2.2" 0.2" 2" 🚿 Regular watering
Jun 2.2" 0.3" 1.9" 🚿 Regular watering
Jul 2.2" 1.3" 0.9" 💧 Light watering
Aug 2.2" 1.6" 0.6" 💧 Light watering
Sep 2.2" 1.1" 1.1" 🚿 Regular watering
Oct 0.8" 0" ❄️ Dormant
Nov 0.4" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Humboldt 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 ~1,230 GDD — county provides 2,214 GDD Excellent fit

Calendula Planting Timeline — Humboldt County, NV

Calendula Planting Calendar

Activity When Date Range
Start Indoors April 18 Apr 18 – May 2
Transplant Outdoors May 30 May 30 – Jun 13
Direct Sow May 2 May 2 – May 23
Bloom July 18 Jul 18 – Oct 24

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · 1-2 times/week

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

108 days in Humboldt County

Growing Tips for Calendula in Humboldt County

Direct sow Calendula outdoors after May 30 in Humboldt County when soil has warmed and frost danger has passed.

Sandy soil in Humboldt County dries quickly — mulch Calendula with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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

Humboldt County receives only 8" 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 Humboldt County, NV?

Humboldt County is in Zone 6b with an average last frost of May 30. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Humboldt County, NV?

Humboldt County, Nevada is in USDA Hardiness Zone 6b. The average last spring frost is May 30 and first fall frost is September 15.

🌱

Your Humboldt County Garden Planner — Free

A 22-page printable planner built for Humboldt County (Zone 6b). 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 Humboldt County, NV. 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.