Blog

When to plant Ageratum in Inyo County, CA

Aim to plant Ageratum in Inyo County on or after January 1; the window stays open through January 22. Inyo County's 330-day frost-free season gives you plenty of room for a spring and fall cycle.

When to Plant Ageratum in Inyo County, CA

Inyo County, California Zone 8b June

Your June gardening checklist

A quick June briefing for Inyo County, California gardeners — what's urgent, what's next, and what can wait.

Avg. last frost January 15
Avg. first frost December 10
Soil temp (4") 68°F
Watering Critical
Pest pressure High
Daylight 14.5 hrs
  1. Bring in the ageratum

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

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

Instant PDF download. No spam, unsubscribe any time.

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.

Inyo County, California is in USDA Zone 8b. The average last spring frost is January 15 and the first fall frost is December 10, giving you a growing season of approximately 329 days.

At an elevation of 4,562 feet, Inyo County receives approximately 16.4 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Ageratum during the growing season. 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
Inyo County, CA (Zone 8b) Year-round
329 days
Last Spring Frost January 15
329 growing days
First Fall Frost December 10

Inyo County Soil Profile

Soil Type

Loam

Soil pH

6-7.8

Drainage

Well Drained

Ageratum Planting Risk Windows

Early Start (70% safe) ✓ Fits season (136 days to spare)
Start indoors: Nov 26 Transplant: Dec 24 🌸 Bloom: Feb 18 – Jul 22
Recommended (50%) ✓ Fits season (133 days to spare)
Start indoors: Dec 4 Transplant: Jan 1 🌸 Bloom: Feb 26 – Jul 30
Safe Start (90%) ✓ Fits season (119 days to spare)
Start indoors: Dec 29 Transplant: Jan 26 🌸 Bloom: Mar 23 – Aug 24

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 Inyo County

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

Soil pH

Your soil pH (6.0–7.8) overlaps with Ageratum's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Ageratum.

How to Plant Ageratum

8"
Between Plants
10"
Between Rows

Succession Planting Ageratum

6
successive plantings in your 329-day season

Sow every 6.9 weeks. Last sowing by Sep 26 to harvest before frost.

Ageratum Water Budget

Plant needs
1.0″/week
Rainfall provides
0.2″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 2,789 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 4.3" 3.3" 1" 💧 Light watering
Feb 4.3" 3.4" 0.9" 💧 Light watering
Mar 4.3" 2.5" 1.8" 💧 Light watering
Apr 4.3" 1.3" 3" 🚿 Regular watering
May 4.3" 0.5" 3.8" 🚿 Regular watering
Jun 4.3" 0.1" 4.2" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.2" 4.1" 🚿 Regular watering
Oct 4.3" 0.6" 3.7" 🚿 Regular watering
Nov 4.3" 1.7" 2.6" 🚿 Regular watering
Dec 4.3" 2.8" 1.5" 💧 Light watering

Water needs are for active growing months only (Jan–Dec in Inyo 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 ~1,080 GDD — county provides 5,280 GDD Excellent fit

Ageratum Planting Timeline — Inyo County, CA

Ageratum Planting Calendar

Activity When Date Range
Start Indoors December 4 Dec 4 – Dec 18
Transplant Outdoors January 1 Jan 1 – Jan 15
Direct Sow January 1 Jan 1 – Jan 22
Bloom February 26 Feb 26 – Jul 30

· 8" apart · Rows 10" apart

Month-by-Month Timeline

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

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: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

329 days in Inyo County

Growing Tips for Ageratum in Inyo County

Direct sow Ageratum outdoors after January 15 in Inyo County when soil has warmed and frost danger has passed.

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

Inyo County receives only 16" 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 Inyo County, CA?

Inyo County is in Zone 8b with an average last frost of January 15. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Inyo County, CA?

Inyo County, California is in USDA Hardiness Zone 8b. The average last spring frost is January 15 and first fall frost is December 10.

When should I plant Ageratum in Inyo County, CA?

In Inyo County, CA, plant Ageratum after the last frost (around January 15) and before the first frost (around December 10). Best results when soil holds above 50°F.

What growing zone is Inyo County, CA for Ageratum?

Inyo County sits in USDA Zone 8b. Ageratum grows reliably in zones 3a through 11b, so it's a good fit here.

Can Ageratum grow in Inyo County's climate?

Yes — Ageratum grows well in Inyo County's temperate climate. Inyo County averages a 330-day frost-free season, with last frost around January 15 and first frost around December 10.

🌱

Your Inyo County Garden Planner — Free

A 22-page printable planner built for Inyo County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Inyo County, CA. 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.