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When to Plant Salvia in Hunterdon County, NJ

Hunterdon County, New Jersey Zone 7a June

June to-do list for Hunterdon County, New Jersey

Each item below is timed to Hunterdon County, New Jersey's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 12
Avg. first frost October 29
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 14.9 hrs
  1. Start salvia under lights

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

  2. Harvest salvia as they ripen

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

July will be here before you know it — start on
  • First harvests: salvia

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Salvia splendens is a tender perennial from Brazil grown as a warm-season annual throughout the US. Its vivid, upright flower spikes in brilliant red, purple, and coral are irresistible to hummingbirds, bees, and butterflies. One of the longest-blooming annuals in the landscape — plants bloom from early summer until hard frost with minimal deadheading required.

Hunterdon County, New Jersey is in USDA Zone 7a. The average last spring frost is April 12 and the first fall frost is October 29, giving you a growing season of approximately 200 days.

At an elevation of 534 feet, Hunterdon County receives approximately 46.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Salvia during the growing season.

Annual Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
Hunterdon County, NJ (Zone 7a) Long season
200 days
Last Spring Frost April 12
200 growing days
First Fall Frost October 29
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Hunterdon County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.3

Drainage

Well Drained

Salvia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (14 days to spare)
Start indoors: Feb 8 Transplant: Apr 5 🌸 Bloom: Jun 14 – Oct 4
Recommended (50%) ✓ Fits season (18 days to spare)
Start indoors: Feb 15 Transplant: Apr 12 🌸 Bloom: Jun 21 – Oct 11
Safe Start (90%) ✓ Fits season (13 days to spare)
Start indoors: Mar 6 Transplant: May 1 🌸 Bloom: Jul 10 – Oct 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 Hunterdon County

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

Soil pH

Your soil pH (5.2–6.3) overlaps with Salvia's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.7%). Annual compost additions will help Salvia.

How to Plant Salvia

12"
Between Plants
18"
Between Rows

Succession Planting Salvia

3
successive plantings in your 200-day season

Sow every 8 weeks. Last sowing by Jul 31 to harvest before frost.

Salvia Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 31 gal / 100 sq ft

Monthly Watering Guide for Salvia

Salvia needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Salvia Needs Rainfall You Supplement Action
Jan 3.7" 0" ❄️ Dormant
Feb 2.7" 0" ❄️ Dormant
Mar 4.1" 0" ❄️ Dormant
Apr 4.3" 3.8" 0.5" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 4.1" 0.2" 💧 Light watering
Jul 4.3" 5.1" 0" ✅ Rainfall sufficient
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 4.1" 0.2" 💧 Light watering
Oct 4.3" 4.1" 0.2" 💧 Light watering
Nov 3.7" 0" ❄️ Dormant
Dec 3.5" 0" ❄️ Dormant

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

Salvia 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.

Salvia needs ~1,400 GDD — county provides 3,500 GDD Excellent fit

Salvia Planting Timeline — Hunterdon County, NJ

Salvia Planting Calendar

Activity When Date Range
Start Indoors February 15 Feb 15 – Mar 1
Transplant Outdoors April 12 Apr 12 – Apr 26
Bloom June 21 Jun 21 – Oct 11

· 12" apart · Rows 18" apart

Month-by-Month Timeline

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

1"/week · Only during dry spells

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

200 days in Hunterdon County

Growing Tips for Salvia in Hunterdon County

Direct sow Salvia outdoors after April 12 in Hunterdon County when soil has warmed and frost danger has passed.

General growing tips

Start indoors 8-10 weeks before last frost; seeds need 65-70°F soil and light to germinate (surface-sow, do not cover). Transplant after last frost when soil has warmed. Salvia is frost-sensitive — even a light frost kills plants. Pinch spent spikes to encourage continued bloom. Tolerates heat and humidity well once established. In zones 9b-11b can be grown as a short-lived perennial.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Salvia in Hunterdon County, NJ?

Hunterdon County is in Zone 7a with an average last frost of April 12. Plan your Salvia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hunterdon County, NJ?

Hunterdon County, New Jersey is in USDA Hardiness Zone 7a. The average last spring frost is April 12 and first fall frost is October 29.

🌱

Your Hunterdon County Garden Planner — Free

A 22-page printable planner built for Hunterdon 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 Hunterdon County, NJ. 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.