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When to Plant Vinca (Annual) in Hamilton County, NY

Hamilton County, New York Zone 4b June

What to do in June

We've pulled the most time-sensitive tasks for Hamilton County, New York this June and put them front and centre. Tackle them in order.

Avg. last frost May 20
Avg. first frost September 28
Soil temp (4") 63°F
Watering Low
Pest pressure Moderate
Daylight 15.2 hrs
  1. Plant out vinca (annual)

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

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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.

Hamilton County, New York is in USDA Zone 4b. The average last spring frost is May 20 and the first fall frost is September 28, giving you a growing season of approximately 131 days.

At an elevation of 959 feet, Hamilton County receives approximately 49.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Vinca (Annual) to ensure they mature before fall.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant
Hamilton County, NY (Zone 4b) Short season
131 days
Last Spring Frost May 20
131 growing days
First Fall Frost September 28

Hamilton County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.2

Drainage

Well Drained

Vinca (Annual) Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 25 Transplant: May 27 🌸 Bloom: Aug 5 – Oct 14
Recommended (50%) ✗ May not fit
Start indoors: Mar 4 Transplant: Jun 3 🌸 Bloom: Aug 12 – Oct 21
Safe Start (90%) ✗ May not fit
Start indoors: Mar 15 Transplant: Jun 14 🌸 Bloom: Aug 23 – 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 Hamilton County

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

Soil pH

Your soil pH (5.2–6.2) is more acidic than Vinca (Annual) prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Vinca (Annual) prefers dry conditions but your soil drains poorly. Use raised beds or mounded rows to prevent root rot.

Organic Matter

Organic matter is moderate (3.4%). 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 131-day season

Sow every 8 weeks. Last sowing by Jun 30 to harvest before frost.

Vinca (Annual) Water Budget

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

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 4" 0" ❄️ Dormant
Feb 2.9" 0" ❄️ Dormant
Mar 3.5" 0" ❄️ Dormant
Apr 4.8" 0" ❄️ Dormant
May 2.2" 4.1" 0" ✅ Rainfall sufficient
Jun 2.2" 5" 0" ✅ Rainfall sufficient
Jul 2.2" 5.1" 0" ✅ Rainfall sufficient
Aug 2.2" 4.3" 0" ✅ Rainfall sufficient
Sep 2.2" 4.6" 0" ✅ Rainfall sufficient
Oct 3.9" 0" ❄️ Dormant
Nov 3.7" 0" ❄️ Dormant
Dec 3.4" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Hamilton 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 ~860 GDD — county provides 1,408 GDD Excellent fit

Vinca (Annual) Planting Timeline — Hamilton County, NY

Vinca (Annual) Planting Calendar

Activity When Date Range
Start Indoors March 4 Mar 4 – Mar 18
Transplant Outdoors June 3 Jun 3 – Jun 17
Bloom August 12 Aug 12 – Oct 21

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May
June Transplant Outdoors
July
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

70–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 4b

📆 Growing Season

131 days in Hamilton County

Growing Tips for Vinca (Annual) in Hamilton County

Direct sow Vinca (Annual) outdoors after May 20 in Hamilton County when soil has warmed and frost danger has passed.

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 Hamilton County, NY?

Hamilton County is in Zone 4b with an average last frost of May 20. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hamilton County, NY?

Hamilton County, New York is in USDA Hardiness Zone 4b. The average last spring frost is May 20 and first fall frost is September 28.

🌱

Your Hamilton County Garden Planner — Free

A 22-page printable planner built for Hamilton County (Zone 4b). 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 Hamilton County, NY. Local conditions may vary. Last updated: June 2026.

Sources & credits

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