When Is The Best Time To Plant Rhubarb

Rhubarb crowns planted in early spring produce the most vigorous stalks for years to come. But if you’re wondering when is the best time to plant rhubarb, the answer depends on your climate and whether you start from crowns or seeds. This guide breaks down the timing so you get a harvest that lasts for decades.

Rhubarb is a hardy perennial that thrives in cool weather. It needs a winter chill to produce well. Planting at the right time ensures strong roots and plenty of stalks each spring.

The ideal window for planting rhubarb is early spring, as soon as the soil is workable. In most regions, that means March or April. The ground should be thawed and not waterlogged. This timing gives the plant a full growing season to establish before winter.

For gardeners in warmer climates, fall planting can work too. Zones 8 and above often have mild winters. Plant in September or October so roots develop before the heat returns. But spring is still the safest bet for most people.

Spring Planting Benefits

Spring planting aligns with rhubarb’s natural growth cycle. The plant wakes up from dormancy and puts energy into root and leaf development. Cool soil temperatures between 40°F and 50°F are perfect for root growth.

Soil is moist from winter rains
Less competition from weeds
Plants have all summer to establish
First harvest possible the following year

Fall Planting Considerations

Fall planting is riskier but possible in mild areas. The key is to plant at least 6 weeks before the first hard frost. This gives roots time to anchor before the ground freezes. Mulch heavily to protect the crown.

In zones 5 and colder, fall planting is not recomended. The plant may not survive the winter. Stick to early spring in these regions.

How To Choose The Right Planting Time For Your Zone

Your USDA hardiness zone determines the best planting window. Rhubarb needs a period of cold dormancy, about 500-700 hours below 40°F. Without this, the plant will produce thin, weak stalks.

Zones 3-5: Cold Climates

In these zones, plant as soon as the soil thaws in early spring. That’s usually March or early April. The ground might still be cold, but rhubarb can handle it. Avoid planting in fall because the winter is too harsh.

Wait until soil is dry enough to crumble in your hand
Dig a hole 12 inches deep and wide
Mix in compost or aged manure
Place the crown 2 inches below the soil surface
Water well and mulch with straw

Zones 6-7: Moderate Climates

Spring planting is still best here. Plant in March or April. You can also try a late summer planting in August, but only if you provide shade and consistent water. The plant needs time to establish before frost.

In these zones, rhubarb may go dormant in summer heat. That’s normal. Don’t worry if leaves die back. The roots are still alive.

Zones 8-10: Warm Climates

Growing rhubarb in warm climates is tricky. You need a variety like ‘Victoria’ or ‘Crimson Red’ that tolerates heat. Plant in fall, around October, so the plant experiences cooler weather. Provide afternoon shade and keep soil moist.

In these zones, rhubarb may not live as long. Treat it as a short-lived perennial or even an annual. Expect smaller harvests.

Planting From Crowns Vs Seeds: Timing Differences

Crowns are dormant root pieces with buds. They are the fastest way to start. Seeds take longer and are less predictable. The best time to plant differs for each.

Crowns

Plant crowns in early spring. They are available at garden centers in late winter. Order them online in January or February so they arrive in time. Soak the roots in water for an hour before planting.

Crowns should be planted with the buds facing up. Cover with 2 inches of soil. Space them 3 feet apart. They will produce stalks the first year, but don’t harvest until the second year.

Seeds

Start seeds indoors 8-10 weeks before the last frost. That means February or March for most zones. Sow seeds in pots filled with seed starting mix. Keep them moist and warm, around 70°F.

Transplant seedlings outdoors after the last frost, when they have 3-4 true leaves. Space them 2 feet apart. Seeds take longer to mature. You may not harvest until the third year.

Seeds are cheaper but slower
Crowns are faster but more expensive
Seeds give more variety options
Crowns are more reliable for beginners

Preparing The Soil For Rhubarb

Rhubarb needs rich, well-draining soil. Test your soil pH before planting. The ideal range is 6.0 to 6.8. Add lime if the soil is too acidic.

Dig the soil deeply, at least 12 inches. Remove rocks and weeds. Mix in a 2-inch layer of compost or well-rotted manure. Rhubarb is a heavy feeder, so organic matter is essential.

Soil Preparation Steps

Clear the area of grass and weeds
Loosen soil to 12 inches deep
Mix in 2-3 inches of compost
Add a balanced fertilizer like 10-10-10
Rake the bed smooth

If your soil is heavy clay, consider raised beds. Rhubarb hates wet feet. Good drainage prevents root rot.

Common Planting Mistakes To Avoid

Many gardeners plant rhubarb at the wrong depth. The crown should be 2 inches below the surface. Planting too deep causes rot. Planting too shallow exposes the roots to frost.

Another mistake is planting in shade. Rhubarb needs full sun for best growth. Partial shade is ok in warm climates, but 6 hours of sun is ideal.

Don’t plant too close to trees or shrubs
Don’t overwater after planting
Don’t harvest the first year
Don’t plant in compacted soil

Also, avoid planting rhubarb near other aggressive perennials like mint. They will compete for nutrients. Give rhubarb its own space.

Care After Planting

Water your newly planted rhubarb deeply once a week. Keep the soil moist but not soggy. Mulch with straw or wood chips to retain moisture and suppress weeds.

In the first year, let the plant grow without harvesting. The leaves will feed the roots. Remove any flower stalks that appear. Flowering weakens the plant.

Fertilizing Schedule

Fertilize in early spring with a balanced fertilizer. Apply again after harvest in mid-summer. Use a low-nitrogen formula to avoid excessive leaf growth. Too much nitrogen makes stalks thin.

Side-dress with compost in fall. This adds organic matter for the next season. Avoid fresh manure, which can burn roots.

Harvesting Rhubarb The Right Way

You can start harvesting in the second year. Take only 1/3 of the stalks at a time. Pull them by twisting and tugging gently. Cut off the leaves, which are toxic, and compost them.

Harvest in spring and early summer. Stop harvesting by July to let the plant store energy for winter. In warm climates, you may get a second harvest in fall.

Stalks should be 12-18 inches long
Harvest when stalks are firm and crisp
Don’t harvest after a hard freeze
Discard any stalks that are soft or mushy

Dividing And Transplanting Rhubarb

Rhubarb plants get crowded after 5-7 years. Divide them in early spring or fall. Dig up the entire root ball. Use a sharp shovel to split it into sections, each with 2-3 buds.

Replant the divisions at the same depth. Space them 3 feet apart. Water well. Dividing rejuvenates the plant and gives you more crowns to share.

When To Divide

Divide when stalks become thin and spindly. This is a sign the plant is overcrowded. Early spring is the best time, just as growth begins. Fall division is also possible in mild climates.

After dividing, the plant may take a year to recover. Don’t harvest from divisions until the second year.

Pest And Disease Management

Rhubarb is generally pest-free. But watch for rhubarb curculio, a small beetle that damages stalks. Handpick them off. Also, look for crown rot, which is caused by wet soil. Improve drainage to prevent it.

Slugs and snails can attack young leaves. Use diatomaceous earth or beer traps. Remove debris where they hide.

Keep the garden clean
Water at the base, not on leaves
Rotate planting locations every 5 years
Remove diseased plants immediately

Frequently Asked Questions

Can I plant rhubarb in summer?

Summer planting is risky because heat stresses the plant. If you must, plant in late summer with shade and consistent water. But spring or fall is better.

How late can I plant rhubarb in spring?

You can plant rhubarb up until early May in most zones. After that, the heat may hinder root growth. Plant as early as possible for best results.

What happens if I plant rhubarb too late?

Late planting gives the plant less time to establish before winter. It may not survive the cold or produce well the next year. Stick to the recommended window.

Is it better to plant rhubarb in fall or spring?

Spring is better for most climates. Fall works only in zones 8 and above. Spring gives the plant a full season to grow strong roots.

Can I plant rhubarb in a pot?

Yes, but choose a large pot, at least 18 inches wide. Use quality potting soil. Water frequently. Potted rhubarb needs winter protection in cold zones.

Final Tips For Success

Plant rhubarb in a spot where it can stay for years. It does not like to be moved. Choose a location with full sun and good drainage. Add compost every year to keep the soil fertile.

Be patient. Rhubarb takes time to establish. The first harvest is small, but by the third year, you will have plenty. With proper care, a single plant can produce for 15 years or more.

Remember that rhubarb leaves are poisonous. Do not eat them. Only the stalks are safe. Cook them with sugar to balance the tartness.

Now you know when is the best time to plant rhubarb. Early spring is the golden window. Get your crowns in the ground as soon as the soil is workable. Your future self will thank you when you are pulling thick, ruby-red stalks every spring.

Happy gardening, and enjoy your rhubarb for years to come.