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When to Plant Ageratum in Sioux County, NE

Sioux County, Nebraska Zone 5a June

Your June gardening checklist

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Sioux County, Nebraska.

Avg. last frost May 16
Avg. first frost September 22
Soil temp (4") 64°F
Watering High
Pest pressure High
Daylight 15.1 hrs
Coming up in July — start thinking about
  • Starting indoors: ageratum
  • 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.

Sioux County, Nebraska is in USDA Zone 5a. The average last spring frost is May 16 and the first fall frost is September 22, giving you a growing season of approximately 129 days.

At an elevation of 775 feet, Sioux County receives approximately 24.4 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Ageratum to ensure they mature before fall.

Annual Blooms in Multi-season Pollinator-friendly Good for cutting
Sioux County, NE (Zone 5a) Short season
129 days
Last Spring Frost May 16
129 growing days
First Fall Frost September 22

Sioux County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.2

Drainage

Well Drained

Ageratum Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 23 Transplant: May 18 🌸 Bloom: Jul 13 – Oct 5
Recommended (50%) ✗ May not fit
Start indoors: Mar 28 Transplant: May 23 🌸 Bloom: Jul 18 – Oct 10
Safe Start (90%) ✗ May not fit
Start indoors: Apr 21 Transplant: Jun 16 🌸 Bloom: Aug 11 – Nov 3

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 Sioux County

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

Soil pH

Your soil pH (6.3–7.2) overlaps with Ageratum's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — Ageratum will thrive.

How to Plant Ageratum

8"
Between Plants
10"
Between Rows

Succession Planting Ageratum

2
successive plantings in your 129-day season

Sow every 6.9 weeks. Last sowing by Jul 09 to harvest before frost.

Ageratum Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 283 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 1.7" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 2.5" 0" ❄️ Dormant
May 4.3" 2.7" 1.6" 💧 Light watering
Jun 4.3" 1.6" 2.7" 🚿 Regular watering
Jul 4.3" 2" 2.3" 🚿 Regular watering
Aug 4.3" 2.8" 1.5" 💧 Light watering
Sep 4.3" 2.2" 2.1" 💧 Light watering
Oct 2.1" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Sioux 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 ~878 GDD — county provides 1,677 GDD Excellent fit

Ageratum Planting Timeline — Sioux County, NE

Ageratum Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 – Apr 11
Transplant Outdoors May 23 May 23 – Jun 6
Direct Sow May 23 May 23 – Jun 13
Bloom July 18 Jul 18 – Oct 10

· 8" apart · Rows 10" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

60–75 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

129 days in Sioux County

Growing Tips for Ageratum in Sioux County

Direct sow Ageratum outdoors after May 16 in Sioux 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.

Sioux County receives only 24" 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 Sioux County, NE?

Sioux County is in Zone 5a with an average last frost of May 16. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sioux County, NE?

Sioux County, Nebraska is in USDA Hardiness Zone 5a. The average last spring frost is May 16 and first fall frost is September 22.

🌱

Your Sioux County Garden Planner — Free

A 22-page printable planner built for Sioux County (Zone 5a). 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 Sioux County, NE. Local conditions may vary. Last updated: June 2026.

Sources & credits

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