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When to Plant Ageratum in Douglas County, NV

Douglas County, Nevada Zone 6b July

Top priorities for Douglas County, Nevada gardeners in July

July rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Douglas County, Nevada.

Avg. last frost May 12
Avg. first frost October 10
Soil temp (4") 63°F
Watering High
Pest pressure High
Daylight 14.5 hrs
  1. Start harvesting ageratum

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

Looking ahead to August
  • First harvests: ageratum

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Ageratum (Ageratum houstonianum), the floss flower, produces clusters of fluffy, powder-puff blooms in the rare sky-blue and lavender tones difficult to find among warm-season annuals. Compact mounding habit makes it ideal as a front-of-border edging plant. Blooms from early summer through fall with minimal deadheading; heat and humidity tolerant once established.

Douglas County, Nevada is in USDA Zone 6b. The average last spring frost is May 12 and the first fall frost is October 10, giving you a growing season of approximately 151 days.

At an elevation of 5,945 feet, Douglas County receives approximately 9.5 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 98°F, so Ageratum may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Ageratum will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Ageratum successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Multi-season Pollinator-friendly Good for cutting
Douglas County, NV (Zone 6b) Moderate season
151 days
Last Spring Frost May 12
151 growing days
First Fall Frost October 10

Douglas County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.3-8.7

Drainage

Well Drained

Ageratum Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 13 Transplant: May 1 🌸 Bloom: Jun 26 – Oct 9
Recommended (50%) ✗ May not fit
Start indoors: Mar 24 Transplant: May 12 🌸 Bloom: Jul 7 – Oct 20
Safe Start (90%) ✗ May not fit
Start indoors: Apr 18 Transplant: Jun 6 🌸 Bloom: Aug 1 – Nov 14

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 Douglas County

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

Soil pH

Your soil pH (7.3–8.7) is more alkaline than Ageratum prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Ageratum.

Organic Matter

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

How to Plant Ageratum

8"
Between Plants
10"
Between Rows

Succession Planting Ageratum

2
successive plantings in your 151-day season

Sow every 6.9 weeks. Last sowing by Jul 27 to harvest before frost.

Ageratum Water Budget

Plant needs
1.0″/week
Rainfall provides
0.3″/week
You supply
1.2″/week
Watering frequency 2-3 times/week
Season total 1,670 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Ageratum

Ageratum needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Ageratum Needs Rainfall You Supplement Action
Jan 0.7" 0" ❄️ Dormant
Feb 0.6" 0" ❄️ Dormant
Mar 0.5" 0" ❄️ Dormant
Apr 0.3" 0" ❄️ Dormant
May 4.3" 0.2" 4.1" 🚿 Regular watering
Jun 4.3" 0.4" 3.9" 🚿 Regular watering
Jul 4.3" 1.4" 2.9" 🚿 Regular watering
Aug 4.3" 2.1" 2.2" 🚿 Regular watering
Sep 4.3" 1.3" 3" 🚿 Regular watering
Oct 4.3" 0.9" 3.4" 🚿 Regular watering
Nov 0.5" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

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

Ageratum 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.

Ageratum needs ~1,586 GDD — county provides 3,548 GDD Excellent fit

Ageratum Planting Timeline — Douglas County, NV

Ageratum Planting Calendar

Activity When Date Range
Start Indoors March 24 Mar 24 – Apr 7
Transplant Outdoors May 12 May 12 – May 26
Direct Sow May 12 May 12 – Jun 2
Bloom July 7 Jul 7 – Oct 20

· 8" apart · Rows 10" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

60–75 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

151 days in Douglas County

Growing Tips for Ageratum in Douglas County

Direct sow Ageratum outdoors after May 12 in Douglas County when soil has warmed and frost danger has passed.

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

With summer highs reaching 98°F in Douglas County, provide afternoon shade for Ageratum and water deeply in the morning.

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

Douglas County receives only 10" of rain annually. Ageratum needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 6–8 weeks before last frost — do not cover seed; it needs light to germinate. Can be direct-sown after last frost once soil warms to 60°F. Transplant or thin to proper spacing after frost danger passes. Deadheading isn't strictly required but tidying spent clusters improves appearance. Provide consistent moisture; drought causes premature setting. Avoid deep shade — blooms best in full sun to light afternoon shade.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Ageratum in Douglas County, NV?

Douglas County is in Zone 6b with an average last frost of May 12. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Douglas County, NV?

Douglas County, Nevada is in USDA Hardiness Zone 6b. The average last spring frost is May 12 and first fall frost is October 10.

🌱

Your Douglas County Garden Planner — Free

A 22-page printable planner built for Douglas 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 Douglas County, NV. Local conditions may vary. Last updated: July 2026.

Sources & credits

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