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When to Plant Marigolds in Clark County, NV

Clark County, Nevada Zone 9b July

What to do in July

Your Clark County, Nevada garden is entering a new phase. Here's what's on the schedule for July and why each task matters now.

Avg. last frost February 28
Avg. first frost November 23
Soil temp (4") 87°F
Watering High
Pest pressure High
Daylight 14.2 hrs
  1. It's harvest week for marigolds

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

Coming up in August — start thinking about
  • First harvests: marigolds

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Marigolds (Tagetes patula) are warm-season annuals beloved for their cheerful orange, yellow, and red blooms — and for their well-documented ability to repel pest nematodes in vegetable beds. Easy from seed, drought-tolerant once established, and bloom from early summer until the first hard frost.

Clark County, Nevada is in USDA Zone 9b. The average last spring frost is February 28 and the first fall frost is November 23, giving you a growing season of approximately 268 days.

At an elevation of 2,811 feet, Clark County receives approximately 9.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 111°F, so Marigolds may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Marigolds will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Marigolds successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Clark County, NV (Zone 9b) Long season
268 days
Last Spring Frost February 28
268 growing days
First Fall Frost November 23

Clark County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.3-8.4

Drainage

Well Drained

Marigolds Planting Risk Windows

Early Start (70% safe) ✓ Fits season (63 days to spare)
Start indoors: Jan 7 Transplant: Jan 21 🌸 Bloom: Mar 18 – Sep 9
Recommended (50%) ✓ Fits season (58 days to spare)
Start indoors: Jan 24 Transplant: Feb 7 🌸 Bloom: Apr 4 – Sep 26
Safe Start (90%) ✓ Fits season (44 days to spare)
Start indoors: Mar 1 Transplant: Mar 15 🌸 Bloom: May 10 – Nov 1

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 Clark County

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

Soil pH

Your soil pH (7.3–8.4) is more alkaline than Marigolds prefers (6.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Marigolds.

Organic Matter

Organic matter is low (0.8%). Add 2-3 inches of compost before planting Marigolds.

How to Plant Marigolds

0.3"
Planting Depth
10"
Between Plants
12"
Between Rows

Succession Planting Marigolds

6
successive plantings in your 268-day season

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

Marigolds Water Budget

Plant needs
0.5″/week
Rainfall provides
0.2″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,450 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Marigolds

Marigolds 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 Marigolds Needs Rainfall You Supplement Action
Jan 0.7" 0" ❄️ Dormant
Feb 2.2" 0.6" 1.6" 🚿 Regular watering
Mar 2.2" 0.6" 1.6" 🚿 Regular watering
Apr 2.2" 0.3" 1.9" 🚿 Regular watering
May 2.2" 0.2" 2" 🚿 Regular watering
Jun 2.2" 0.3" 1.9" 🚿 Regular watering
Jul 2.2" 1.5" 0.7" 💧 Light watering
Aug 2.2" 1.9" 0.3" 💧 Light watering
Sep 2.2" 1.2" 1" 💧 Light watering
Oct 2.2" 0.9" 1.3" 🚿 Regular watering
Nov 2.2" 0.5" 1.7" 🚿 Regular watering
Dec 0.7" 0" ❄️ Dormant

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

Marigolds 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.

Marigolds needs ~1,995 GDD — county provides 8,944 GDD Excellent fit

Marigolds Planting Timeline — Clark County, NV

Marigolds Planting Calendar

Activity When Date Range
Start Indoors January 24 Jan 24 – Feb 7
Transplant Outdoors February 7 Feb 7 – Feb 21
Direct Sow February 7 Feb 7 – Feb 28
Bloom April 4 Apr 4 – Sep 26

Plant 0.3" deep · 10" apart · Rows 12" apart

Month-by-Month Timeline

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

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 6–7.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

268 days in Clark County

Growing Tips for Marigolds in Clark County

Direct sow Marigolds outdoors after February 28 in Clark County when soil has warmed and frost danger has passed.

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

With summer highs reaching 111°F in Clark County, provide afternoon shade for Marigolds and water deeply in the morning.

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

General growing tips

Direct-sow after last frost or start indoors 4-6 weeks earlier. Deadhead spent blooms to keep new flowers coming. French marigolds (T. patula) are the most reliable nematode repellents — plant a band around vegetable beds. Tolerate poor soil but bloom best with monthly compost.

Companion Planting

Good Companions

Avoid Planting Near

  • Beans
  • Cabbage

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Marigolds Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let flower heads dry on plant. Pull dried petals to reveal seeds.
Storage Store in envelopes; viable 3 years at 35°F, under 50% humidity.

Very easy to save. Seeds are the long, thin, dark pieces inside the dried flower head.

Frequently Asked Questions

When should I plant Marigolds in Clark County, NV?

Clark County is in Zone 9b with an average last frost of February 28. Plan your Marigolds planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clark County, NV?

Clark County, Nevada is in USDA Hardiness Zone 9b. The average last spring frost is February 28 and first fall frost is November 23.

🌱

Your Clark County Garden Planner — Free

A 22-page printable planner built for Clark County (Zone 9b). 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 Clark County, NV. Local conditions may vary. Last updated: July 2026.

Sources & credits

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