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When to plant Nasturtium in Buena Vista County County,

For Buena Vista County County, gardeners: plant Nasturtium May 2 through May 23 once soil reads 50°F.

When to Plant Nasturtium in Buena Vista County, IA

Buena Vista County, Iowa Zone 5a June

This month in Buena Vista County, Iowa

Welcome to June in Zone 5a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 25
Avg. first frost October 10
Soil temp (4") 67°F
Watering Low
Pest pressure High
Daylight 15.1 hrs
  1. Start harvesting nasturtium

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Coming up in July — start thinking about
  • 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.

Buena Vista County, Iowa is in USDA Zone 5a. The average last spring frost is April 25 and the first fall frost is October 10, giving you a growing season of approximately 168 days.

At an elevation of 604 feet, Buena Vista County receives approximately 33.6 inches of rainfall annually with predominantly silt 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
Buena Vista County, IA (Zone 5a) Moderate season
168 days
Last Spring Frost April 25
168 growing days
First Fall Frost October 10
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Buena Vista County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7

Drainage

Well Drained

Nasturtium Planting Risk Windows

Early Start (70% safe) ✓ Fits season (5 days to spare)
Start indoors: Mar 23 Transplant: Apr 27 🌸 Bloom: Jun 22 – Sep 28
Recommended (50%) ✓ Fits season (7 days to spare)
Start indoors: Mar 28 Transplant: May 2 🌸 Bloom: Jun 27 – Oct 3
Safe Start (90%) ✓ Fits season (7 days to spare)
Start indoors: Apr 13 Transplant: May 18 🌸 Bloom: Jul 13 – Oct 19

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 Buena Vista County

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

Soil pH

Your soil pH (5.8–7.0) overlaps with Nasturtium's range (6.0–8.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.6%) — Nasturtium will thrive.

How to Plant Nasturtium

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

Succession Planting Nasturtium

3
successive plantings in your 168-day season

Sow every 6.3 weeks. Last sowing by Aug 06 to harvest before frost.

Nasturtium Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/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 1.2" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.2" 3.2" 0" ✅ Rainfall sufficient
May 2.2" 3.8" 0" ✅ Rainfall sufficient
Jun 2.2" 4.8" 0" ✅ Rainfall sufficient
Jul 2.2" 4" 0" ✅ Rainfall sufficient
Aug 2.2" 3.2" 0" ✅ Rainfall sufficient
Sep 2.2" 3.1" 0" ✅ Rainfall sufficient
Oct 2.2" 2.7" 0" ✅ Rainfall sufficient
Nov 2" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Buena Vista 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 2,058 GDD Excellent fit

Nasturtium Planting Timeline — Buena Vista County, IA

Nasturtium Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 – Apr 11
Transplant Outdoors May 2 May 2 – May 16
Direct Sow May 2 May 2 – May 23
Bloom June 27 Jun 27 – Oct 3

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 5a

📆 Growing Season

168 days in Buena Vista County

Growing Tips for Nasturtium in Buena Vista County

Direct sow Nasturtium outdoors after April 25 in Buena Vista 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 Buena Vista County, IA?

Buena Vista County is in Zone 5a with an average last frost of April 25. Plan your Nasturtium planting based on this frost date — see the calendar above for exact timing.

What planting zone is Buena Vista County, IA?

Buena Vista County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 25 and first fall frost is October 10.

When should I plant Nasturtium in Buena Vista County County, ?

In Buena Vista County County, , plant Nasturtium after the last frost (around April 25) and before the first frost (around October 10). Best results when soil holds above 50°F.

What growing zone is Buena Vista County County, for Nasturtium?

Buena Vista County County sits in USDA Zone 5a. Nasturtium grows reliably in zones 2a through 11b, so it's a good fit here.

Can Nasturtium grow in Buena Vista County County's climate?

Yes — Nasturtium grows well in Buena Vista County County's temperate climate. Buena Vista County County averages a 168-day frost-free season, with last frost around April 25 and first frost around October 10.

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Your Buena Vista County Garden Planner — Free

A 22-page printable planner built for Buena Vista 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 Buena Vista County, IA. 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.