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When to Plant Salvia in USDA Zone 4a

Zone 4a Zone 4a June

What to do in June

Your Zone 4a garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost May 13
Avg. first frost September 28
Looking ahead to July
  • Starting indoors: 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.

In Zone 4a, the average last spring frost is around May 6 and the first fall frost is around September 28, giving you a growing season of approximately 145 days.

Annual Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
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Zone 4a Short season
145 days
Last Spring Frost May 6
145 growing days
First Fall Frost September 28

Salvia Planting Timeline — Zone 4a

Where Is USDA Zone 4a?

The map below highlights the states that contain Zone 4a. Click any state to see the Salvia planting schedule for that location.

Prints a clean, ink-friendly version without maps or navigation.

Salvia Planting Calendar — Zone 4a

Activity When Date Range
Start Indoors February 25 Feb 25 – Mar 11
Transplant Outdoors May 20 May 20 – Jun 3
Bloom July 29 Jul 29 – Sep 30

· 12" apart · Rows 18" apart

Month-by-Month Timeline

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

Free Zone 4a Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 4a with start dates, transplant windows, and harvest times.

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Growing Conditions

Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

Days to Maturity

70–90 days

Soil pH

5.5 – 7

Zone Temperature Range

-30°F to -25°F average annual minimum

Growing Season

145 days (Zone 4a average)

Planting Specifications

Plant Spacing12 inches apart
Row Spacing18 inches between rows

Succession Planting Salvia in Zone 4a

2
successive plantings in Zone 4a's ~145-day season

Sow every 8 weeks for continuous harvest throughout the season.

Growing Tips for Salvia in Zone 4a

Zone 4a has a short growing season (~145 days). Start Salvia indoors early and use season-extension techniques like row covers and cold frames.

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

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Saving Salvia Seeds

Recommended for Your Garden

💡
LED Grow Lights $25-60

Full-spectrum LED lights for starting seeds indoors when daylight is limited.

🔥
Seedling Heat Mat $15-35

Warm soil for faster germination of heat-loving crops like tomatoes and peppers.

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Floating Row Covers $12-30

Protect plants from frost, wind, and pests while letting light and water through.

Related Plants

Frequently Asked Questions

When should I plant Salvia in Zone 4a?

In Zone 4a, plan your Salvia planting around the average last frost date of May 6. Start seeds indoors around February 25. Transplant seedlings around May 20.

Can Salvia grow in Zone 4a?

Yes, Salvia can grow well in Zone 4a, hardy in USDA zones 2a through 11b. Zone 4a has a growing season of approximately 145 days, which is sufficient for Salvia (70-90 days to maturity).

When can I harvest Salvia in Zone 4a?

In Zone 4a, expect to harvest Salvia from July 29 – September 30. Salvia takes 70-90 days from planting to harvest.

What is the last frost date for Zone 4a?

The average last spring frost in Zone 4a is around May 6, and the first fall frost is around September 28. This gives a growing season of approximately 145 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Salvia?

Good companion plants for Salvia include Marigolds, Petunias, Zinnias, Lobelia. These companions can help with pest control, pollination, and nutrient sharing.

🌱

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A 22-page printable planner tailored to Zone 4a. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Planting dates are estimates based on average frost dates — 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.