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When to Plant Rosemary in Newport County, RI

Newport County, Rhode Island Zone 7a May

Your May planting checklist for Newport County, Rhode Island

Welcome to May in Zone 7a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 30
Avg. first frost October 13
Soil temp (4") 68°F
Watering Low
Pest pressure Moderate
Daylight 14.3 hrs
  1. Move rosemary into the garden

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

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Rosemary is an aromatic evergreen shrub with needle-like leaves and a piney, citrus flavor. It is a Mediterranean herb that thrives in warm, dry conditions.

Newport County, Rhode Island is in USDA Zone 7a. The average last spring frost is April 30 and the first fall frost is October 13, giving you a growing season of approximately 166 days.

At an elevation of 441 feet, Newport County receives approximately 41.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 94°F, providing good warmth for Rosemary during the growing season.

Newport County, RI (Zone 7a) Moderate season
166 days
Last Spring Frost April 30
166 growing days
First Fall Frost October 13

Newport County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 1 🍅 Harvest: Jul 24 – Dec 11
Recommended (50%) ✗ May not fit
Transplant: May 7 🍅 Harvest: Jul 30 – Dec 17
Safe Start (90%) ✓ Fits season (303 days to spare)
Transplant: May 22 🍅 Harvest: Aug 14 – Jan 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 Newport County

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

Soil pH

Your soil pH (4.8–6.7) is more acidic than Rosemary prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Rosemary.

How to Plant Rosemary

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Rosemary

2
successive plantings in your 166-day season

Sow every 9.1 weeks. Last sowing by Apr 16 to harvest before frost.

Plant Water Budget

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

Monthly Watering Guide for Rosemary

Rosemary needs approximately 0.3 inches of water per week (1.3" per month). Here's how your county's rainfall compares month by month.

Month Rosemary Needs Rainfall You Supplement Action
Jan 2.8" 0" ❄️ Dormant
Feb 2.6" 0" ❄️ Dormant
Mar 3.8" 0" ❄️ Dormant
Apr 1.3" 3.3" 0" ✅ Rainfall sufficient
May 1.3" 4.1" 0" ✅ Rainfall sufficient
Jun 1.3" 4.5" 0" ✅ Rainfall sufficient
Jul 1.3" 4.1" 0" ✅ Rainfall sufficient
Aug 1.3" 3.9" 0" ✅ Rainfall sufficient
Sep 1.3" 3.3" 0" ✅ Rainfall sufficient
Oct 1.3" 3.2" 0" ✅ Rainfall sufficient
Nov 3.1" 0" ❄️ Dormant
Dec 3.2" 0" ❄️ Dormant

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

Rosemary 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.

Rosemary needs ~2,665 GDD — county provides 3,403 GDD Good fit

Rosemary Planting Timeline — Newport County, RI

Rosemary Planting Calendar

Activity When Date Range
Transplant Outdoors May 7 May 7 – May 21
Harvest July 30 Jul 30 – Dec 17

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June
July Harvest
August Harvest
September Harvest
October Harvest
November Harvest
December Harvest

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.3"/week · Natural rainfall sufficient

📅 Days to Maturity

80–180 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7a

📆 Growing Season

166 days in Newport County

Growing Tips for Rosemary in Newport County

Direct sow Rosemary outdoors after April 30 in Newport County when soil has warmed and frost danger has passed.

Your 166.0-day growing season in Newport County is tight for Rosemary (80.0-180.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Grow in well-drained soil and avoid overwatering. In cold climates, grow in containers and bring indoors for winter. Propagate from stem cuttings for faster results than seed.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Rosemary in Newport County, RI?

Newport County is in Zone 7a with an average last frost of April 30. Plan your Rosemary planting based on this frost date — see the calendar above for exact timing.

What planting zone is Newport County, RI?

Newport County, Rhode Island is in USDA Hardiness Zone 7a. The average last spring frost is April 30 and first fall frost is October 13.

🌱

Your Newport County Garden Planner — Free

A 24-page printable planner built for Newport 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.

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 Newport County, RI. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.