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When to Plant Rhubarb in USDA Zone 6a

Zone 6a Zone 6a May

Your May planting checklist for Zone 6a

May is a pivotal month for Zone 6a gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 27
Avg. first frost October 16
  1. Move rhubarb from tray to bed

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

Send me my free Zone 6a Planting Guide →

Rhubarb is a long-lived perennial vegetable grown for its tart, colorful stalks. Only the stalks are edible as the leaves contain toxic oxalic acid.

In Zone 6a, the average last spring frost is around April 10 and the first fall frost is around October 20, giving you a growing season of approximately 193 days.

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Zone 6a Moderate season
193 days
Last Spring Frost April 10
193 growing days
First Fall Frost October 20

Rhubarb Planting Timeline — Zone 6a

Where Is USDA Zone 6a?

The map below highlights the states that contain Zone 6a. Click any state to see the Rhubarb planting schedule for that location.

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

Rhubarb Planting Calendar — Zone 6a

Activity When Date Range
Transplant Outdoors May 1 May 1 – May 15

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

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

Free Zone 6a Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 6a 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

365–730 days

Soil pH

6 – 7

Zone Temperature Range

°F to °F average annual minimum

Growing Season

193 days (Zone average)

Planting Specifications

Planting Depth1 inches
Plant Spacing30 inches apart
Row Spacing42 inches between rows

Growing Tips for Rhubarb in Zone

Zone has a short growing season (~193 days). Start Rhubarb indoors early and use season-extension techniques like row covers and cold frames.

Plant crowns in early spring in rich, well-drained soil. Do not harvest stalks the first year. Pull (do not cut) stalks at harvest to avoid introducing rot.

Companion Planting

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Saving Rhubarb Seeds

Recommended for Your Garden

🌱
Seed Starting Trays $8-20

Start seeds indoors with reusable cell trays and humidity domes.

🧪
Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

🏷️
Garden Plant Markers $6-12

Keep your garden organized with durable, weather-resistant plant labels.

Related Plants

Frequently Asked Questions

When should I plant Rhubarb in Zone 6a?

In Zone 6a, plan your Rhubarb planting around the average last frost date of April 10. Transplant seedlings around May 1.

Can Rhubarb grow in Zone 6a?

Yes, Rhubarb can grow well in Zone 6a, hardy in USDA zones 3a through 8b. Zone 6a has a growing season of approximately 193 days, which is sufficient for Rhubarb (365-730 days to maturity).

What is the last frost date for Zone 6a?

The average last spring frost in Zone 6a is around April 10, and the first fall frost is around October 20. This gives a growing season of approximately 193 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Rhubarb?

Good companion plants for Rhubarb include Garlic, Onion, Cabbage. These companions can help with pest control, pollination, and nutrient sharing.

🌱

Your Free Printable Garden Planner

A 24-page printable planner tailored to your zone. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.

Instant PDF download. No spam, unsubscribe any time.

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: May 2026.

Sources & credits

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