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When to plant Vinca (Annual) in Gooding County, ID

Gooding County's short 153-day growing season means one Vinca (Annual) planting between May 3 and May 17. No fall crop in Zone 7a.

When to Plant Vinca (Annual) in Gooding County, ID

Gooding County, Idaho Zone 7a June

June in the garden — Gooding County, Idaho

Here's what deserves your attention in Gooding County, Idaho this month. Everything below is tailored to Zone 7a and timed around your local frost dates.

Avg. last frost May 3
Avg. first frost October 3
Soil temp (4") 52°F
Watering Critical
Pest pressure High
Daylight 15.2 hrs
Coming up in July — start thinking about
  • Starting indoors: vinca (annual)
  • First harvests: vinca (annual)

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Annual vinca (Catharanthus roseus), also called Madagascar periwinkle, is one of the most heat- and drought-tolerant bedding plants available. Glossy foliage stays attractive all season while cheerful pinwheel blooms continue without deadheading. A top performer in hot, humid Southern summers where impatiens and begonias struggle. Self-cleaning; requires little maintenance once established.

Gooding County, Idaho is in USDA Zone 7a. The average last spring frost is May 3 and the first fall frost is October 3, giving you a growing season of approximately 153 days.

At an elevation of 5,631 feet, Gooding County receives approximately 16.6 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Vinca (Annual) during the growing season. With low rainfall, drip irrigation is essential for growing Vinca (Annual) successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant
Gooding County, ID (Zone 7a) Moderate season
153 days
Last Spring Frost May 3
153 growing days
First Fall Frost October 3

Gooding County Soil Profile

Soil Type

Loam

Soil pH

6.5-8.2

Drainage

Well Drained

Vinca (Annual) Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 18 Transplant: Apr 29 🌸 Bloom: Jul 8 – Oct 28
Recommended (50%) ✗ May not fit
Start indoors: Feb 22 Transplant: May 3 🌸 Bloom: Jul 12 – Nov 1
Safe Start (90%) ✗ May not fit
Start indoors: Mar 23 Transplant: Jun 1 🌸 Bloom: Aug 10 – Nov 30

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 Gooding County

How your county's soil matches Vinca (Annual)'s growing requirements.

Soil pH

Your soil pH (6.5–8.2) is more alkaline than Vinca (Annual) prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Gooding County is excellent for Vinca (Annual) — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Vinca (Annual).

How to Plant Vinca (Annual)

0.1"
Planting Depth
10"
Between Plants
12"
Between Rows

Succession Planting Vinca (Annual)

2
successive plantings in your 153-day season

Sow every 8 weeks. Last sowing by Jul 05 to harvest before frost.

Vinca (Annual) Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 72 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Vinca (Annual)

Vinca (Annual) 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 Vinca (Annual) Needs Rainfall You Supplement Action
Jan 1.2" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.4" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 2.2" 2.2" 0" ✅ Rainfall sufficient
Jun 2.2" 1.1" 1.1" 🚿 Regular watering
Jul 2.2" 1.6" 0.6" 💧 Light watering
Aug 2.2" 1.6" 0.6" 💧 Light watering
Sep 2.2" 1.2" 1" 💧 Light watering
Oct 2.2" 1.5" 0.7" 💧 Light watering
Nov 1.1" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

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

Vinca (Annual) 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.

Vinca (Annual) needs ~1,220 GDD — county provides 2,333 GDD Excellent fit

Vinca (Annual) Planting Timeline — Gooding County, ID

Vinca (Annual) Planting Calendar

Activity When Date Range
Start Indoors February 22 Feb 22 – Mar 8
Transplant Outdoors May 3 May 3 – May 17
Bloom July 12 Jul 12 – Nov 1

Plant 0.1" deep · 10" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

153 days in Gooding County

Growing Tips for Vinca (Annual) in Gooding County

Direct sow Vinca (Annual) outdoors after May 03 in Gooding County when soil has warmed and frost danger has passed.

Gooding County receives only 17" of rain annually. Vinca (Annual) needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 10–12 weeks before last frost — germination requires warm soil (75–80°F) and darkness. Do not cover seeds deeply; they need just a light dusting. Direct sowing is rarely practiced due to slow seedling establishment. Transplant after soil warms and frost danger has passed. Excellent drought tolerance once established; avoid overwatering. Performs best in well-drained beds or containers in full sun.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Vinca (Annual) in Gooding County, ID?

Gooding County is in Zone 7a with an average last frost of May 3. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Gooding County, ID?

Gooding County, Idaho is in USDA Hardiness Zone 7a. The average last spring frost is May 3 and first fall frost is October 3.

When should I plant Vinca (Annual) in Gooding County, ID?

In Gooding County, ID, plant Vinca (Annual) after the last frost (around May 3) and before the first frost (around October 3). Best results when soil holds above 50°F.

What growing zone is Gooding County, ID for Vinca (Annual)?

Gooding County sits in USDA Zone 7a. Vinca (Annual) grows reliably in zones 3a through 11b, so it's a good fit here.

Can Vinca (Annual) grow in Gooding County's climate?

Yes — Vinca (Annual) grows well in Gooding County's temperate climate. Gooding County averages a 153-day frost-free season, with last frost around May 3 and first frost around October 3.

🌱

Your Gooding County Garden Planner — Free

A 22-page printable planner built for Gooding County (Zone 7a). 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 Gooding County, ID. 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.