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When to Plant Nasturtium in Custer County, NE

Custer County, Nebraska Zone 5b June

What to do in June

Your garden in Custer County, Nebraska is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost May 7
Avg. first frost October 2
Soil temp (4") 64°F
Watering Low
Pest pressure High
Daylight 15 hrs
  1. Sow nasturtium in trays indoors

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

Looking ahead to July
  • First harvests: nasturtium

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Nasturtium (Tropaeolum majus) is a fast-growing annual with distinctive round, lily-pad leaves and bold trumpet-shaped blooms in warm oranges, reds, and yellows. Both the flowers and leaves are edible with a peppery watercress flavor. Planted near vegetables, nasturtiums act as a sacrifice trap-crop, luring aphids away from more valuable plants. They thrive in poor, dry soil — rich conditions produce lush foliage but few flowers.

Custer County, Nebraska is in USDA Zone 5b. The average last spring frost is May 7 and the first fall frost is October 2, giving you a growing season of approximately 148 days.

At an elevation of 997 feet, Custer County receives approximately 31.2 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Nasturtium to ensure they mature before fall.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Custer County, NE (Zone 5b) Short season
148 days
Last Spring Frost May 7
148 growing days
First Fall Frost October 2

Custer County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.6

Drainage

Well Drained

Nasturtium Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 1 Transplant: May 6 🌸 Bloom: Jul 1 – Oct 14
Recommended (50%) ✗ May not fit
Start indoors: Apr 9 Transplant: May 14 🌸 Bloom: Jul 9 – Oct 22
Safe Start (90%) ✗ May not fit
Start indoors: Apr 19 Transplant: May 24 🌸 Bloom: Jul 19 – 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 Custer County

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

Soil pH

Your soil pH (6.2–7.6) is within Nasturtium's preferred range (6.0–8.0).

Soil Texture

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

Organic Matter

Organic matter is moderate (3.9%). Annual compost additions will help Nasturtium.

How to Plant Nasturtium

0.5"
Planting Depth
10"
Between Plants
12"
Between Rows

Succession Planting Nasturtium

3
successive plantings in your 148-day season

Sow every 6.3 weeks. Last sowing by Jul 29 to harvest before frost.

Nasturtium Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Nasturtium

Nasturtium 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 Nasturtium Needs Rainfall You Supplement Action
Jan 0.7" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 3.7" 0" ❄️ Dormant
May 2.2" 4.3" 0" ✅ Rainfall sufficient
Jun 2.2" 4.4" 0" ✅ Rainfall sufficient
Jul 2.2" 4.4" 0" ✅ Rainfall sufficient
Aug 2.2" 3.9" 0" ✅ Rainfall sufficient
Sep 2.2" 2.9" 0" ✅ Rainfall sufficient
Oct 2.2" 2.1" 0.1" 💧 Light watering
Nov 1" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

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

Nasturtium 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.

Nasturtium needs ~735 GDD — county provides 1,813 GDD Excellent fit

Nasturtium Planting Timeline — Custer County, NE

Nasturtium Planting Calendar

Activity When Date Range
Start Indoors April 9 Apr 9 – Apr 23
Transplant Outdoors May 14 May 14 – May 28
Direct Sow May 14 May 14 – Jun 4
Bloom July 9 Jul 9 – Oct 22

Plant 0.5" deep · 10" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
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

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

55–65 days

🧪 Soil pH

Needs 6–8 · Your soil: ideal

🗺️ USDA Zone

Zone 5b

📆 Growing Season

148 days in Custer County

Growing Tips for Nasturtium in Custer County

Direct sow Nasturtium outdoors after May 07 in Custer County when soil has warmed and frost danger has passed.

General growing tips

Direct-sow large seeds 1/2 inch deep after last frost; soak seeds overnight to speed germination (7-10 days). Nasturtiums dislike root disturbance so direct sowing is strongly preferred. Avoid fertilizing — poor soil brings the best bloom. Trailing types can cover banks and climb trellises; dwarf types suit containers. In hot climates (zones 9+) plant in fall for winter/spring bloom as plants struggle in peak summer heat.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Nasturtium in Custer County, NE?

Custer County is in Zone 5b with an average last frost of May 7. Plan your Nasturtium planting based on this frost date — see the calendar above for exact timing.

What planting zone is Custer County, NE?

Custer County, Nebraska is in USDA Hardiness Zone 5b. The average last spring frost is May 7 and first fall frost is October 2.

🌱

Your Custer County Garden Planner — Free

A 22-page printable planner built for Custer County (Zone 5b). 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 Custer County, NE. 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.