Best Time To Plant Rhubarb In Missouri

Missouri’s variable weather patterns require monitoring soil temperature rather than relying on calendar dates. Knowing the best time to plant rhubarb in missouri can mean the difference between a thriving patch and a disappointing harvest. Rhubarb is a cold-hardy perennial that needs a winter chill, but it also hates soggy roots and late frosts that damage new growth.

Many gardeners assume they can plant rhubarb as soon as the snow melts. In reality, Missouri’s spring can swing from freezing nights to warm spells in a single week. That’s why timing matters more here than in milder climates.

The ideal window for planting rhubarb in Missouri is early spring, as soon as the soil can be worked. This usually falls between mid-March and early April, depending on your region within the state. Northern Missouri tends to be cooler, so you might wait until late March or early April. Southern Missouri can start a bit earlier, sometimes in early March.

But don’t rush. The key is soil temperature. Rhubarb crowns need soil that is at least 40°F (4°C) at a depth of 4 inches. If the ground is still frozen or waterlogged, wait. Planting too early in cold, wet soil can cause the crowns to rot.

Fall planting is also possible in Missouri, but it’s riskier. If you try fall planting, do it in late September or early October. The plants need at least 6 weeks before the first hard freeze to establish roots. Many Missouri gardeners prefer spring because it gives the plants a full growing season to settle in.

Understanding Missouri’s Climate Zones

Missouri spans USDA hardiness zones 5b to 7a. This means the northern part of the state gets colder winters than the south. Your exact location changes the best planting date.

Northern Missouri (zones 5b-6a): Plant in late March to mid-April.
Central Missouri (zones 6a-6b): Plant from mid-March to early April.
Southern Missouri (zones 6b-7a): Plant from early March to late March.

Check your local frost dates. The average last frost in Missouri ranges from April 10 in the south to April 25 in the north. Rhubarb can handle light frosts, but hard freezes below 28°F can damage new leaves.

Soil Preparation Before Planting

Good soil prep is just as important as timing. Rhubarb thrives in rich, well-draining soil with a pH between 6.0 and 6.8. Missouri’s clay soils can be heavy, so you may need to amend them.

Choose a sunny spot with at least 6 hours of direct sunlight daily.
Dig the soil 12-18 inches deep. Remove rocks and weeds.
Mix in 2-4 inches of compost or well-rotted manure.
Add a balanced fertilizer like 10-10-10 at a rate of 1 pound per 100 square feet.
Test the soil pH. If it’s too acidic, add lime. If too alkaline, add sulfur.

Do this a few weeks before planting so the soil settles. If you plant into freshly turned soil, the crowns might sink too deep.

Choosing Rhubarb Varieties For Missouri

Not all rhubarb varieties perform well in Missouri’s heat and humidity. Some are better suited for cooler climates. Here are reliable choices:

Victoria: An old standard. It’s reliable and produces thick stalks. Tolerates some heat.
Canada Red: Known for its deep red color and sweet flavor. Good for Missouri’s variable weather.
Valentine: A newer variety that resists bolting in heat. Produces early.
Riverside Giant: Large stalks and good disease resistance. Works well in clay soils.

Avoid varieties like ‘Crimson Cherry’ if you live in southern Missouri. They struggle with high humidity and may develop root rot.

How To Plant Rhubarb Crowns

Planting rhubarb is straightforward, but a few details matter. Follow these steps for the best results:

Dig holes about 2 feet apart. Rhubarb spreads, so give it room.
Make each hole deep enough so the crown sits 1-2 inches below the soil surface. In heavy clay, plant slightly shallower.
Place the crown with the buds facing up. Cover with soil and press gently.
Water thoroughly after planting. Keep the soil moist but not soggy for the first few weeks.
Add a 2-inch layer of mulch around the plant, but keep it away from the crown to prevent rot.

If you’re planting from seed, start indoors 8-10 weeks before the last frost. Transplant seedlings outdoors after hardening them off. Seed-grown rhubarb takes longer to establish, so many gardeners prefer crowns.

Caring For Rhubarb After Planting

Once planted, rhubarb needs consistent care. The first year is critical for root development. Don’t harvest any stalks during the first growing season. Let the plant build energy for future harvests.

Water weekly if rainfall is less than 1 inch. Deep watering encourages deep roots.
Fertilize in early spring with a balanced fertilizer. Avoid high-nitrogen formulas that promote leafy growth over stalks.
Remove flower stalks as soon as they appear. Flowering reduces stalk production.
Weed regularly. Rhubarb doesn’t compete well with aggressive weeds.
Divide the plant every 4-5 years to keep it productive. Do this in early spring or fall.

In Missouri’s hot summers, mulch helps keep the soil cool and moist. Use straw, wood chips, or shredded leaves. Reapply mulch each spring.

Common Problems And Solutions

Missouri gardeners face a few specific challenges with rhubarb. Here’s what to watch for:

Root rot: Caused by poor drainage. Plant in raised beds if your soil stays wet.
Leaf spot: Fungal disease in humid weather. Remove affected leaves and improve air circulation.
Bolting: Stalks go to seed too early. This happens in heat stress. Choose bolt-resistant varieties.
Pests: Slugs and snails can damage young leaves. Use diatomaceous earth or beer traps.

If you see yellowing leaves, check for overwatering or nutrient deficiencies. A soil test can help pinpoint the issue.

Harvesting Rhubarb In Missouri

You can start harvesting in the second year after planting. Pick stalks when they are 12-18 inches long and firm. Don’t take more than one-third of the stalks at a time.

Grasp the stalk near the base and pull gently. Twist slightly to detach it.
Cut off the leaves immediately. Rhubarb leaves are toxic due to oxalic acid.
Harvest from April through June. Stop harvesting by mid-summer to let the plant recover.
In hot weather, stalks may become tough and stringy. That’s normal.

Missouri’s heat can cause rhubarb to decline by July. If you want a longer harvest, provide afternoon shade or plant in a cooler spot.

Winter Care For Rhubarb

Rhubarb goes dormant in winter. In Missouri, it usually survives without extra protection. But in northern zones, a layer of mulch helps insulate the crown.

After the first hard freeze, cut back dead foliage to 2 inches above the crown.
Apply 4-6 inches of straw or leaves over the crown. Remove it in early spring.
Avoid using plastic sheeting. It traps moisture and causes rot.
In southern Missouri, winter protection is rarely needed unless a polar vortex hits.

Don’t fertilize in fall. That encourages new growth that will be killed by frost.

Extending The Rhubarb Season

Some Missouri gardeners use techniques to get an earlier start or a later harvest. Here are a few ideas:

Forcing: Cover the crown with a bucket or forcing pot in late winter. This produces tender, pale stalks 2-3 weeks earlier.
Cold frames: Plant in a cold frame to protect from late frosts. You can plant 2 weeks earlier.
Succession planting: Plant a few crowns in a shaded area for a later harvest. They will mature slower.

Forcing works best with established plants that are at least 3 years old. Don’t force the same plant two years in a row.

Frequently Asked Questions

Can I plant rhubarb in summer in Missouri?

Summer planting is not recommended. The heat stresses young plants, and they may not establish before winter. Stick to early spring or early fall.

How deep should I plant rhubarb crowns?

Plant crowns 1-2 inches below the soil surface. In heavy clay, plant just 1 inch deep to prevent water pooling around the crown.

What is the best month to plant rhubarb in Missouri?

March is generally the best month for most of Missouri. Southern areas can plant in late February if the soil is workable. Northern areas may need to wait until early April.

Should I soak rhubarb crowns before planting?

Soaking is not necessary. If the crowns look dry, mist them lightly before planting. Avoid soaking for more than an hour, as it can cause rot.

How long does rhubarb take to grow from seed in Missouri?

From seed, rhubarb takes about 2 years to produce harvestable stalks. Crowns give you a harvest in the second year after planting.

Final Tips For Missouri Rhubarb Growers

Rhubarb is a low-maintenance plant once established. The biggest mistake is planting too early or too late. Watch the soil temperature, not the calendar. Use a soil thermometer to be sure.

If you miss the spring window, you can still plant in early fall. But give the plants enough time to root before the ground freezes. In Missouri, that means planting by early October at the latest.

Remember that rhubarb is a perennial. It will come back year after year if you treat it right. Don’t overharvest in the first few years. Let the plant grow strong roots.

One more thing: rhubarb leaves are poisonous to pets and people. Compost them carefully or throw them away. Only the stalks are edible.

With the right timing and care, you’ll have plenty of rhubarb for pies, jams, and sauces. Missouri’s climate can be tricky, but rhubarb is forgiving if you give it a good start.

So check your soil temperature, pick a sunny spot, and plant those crowns at the right time. Your future rhubarb harvest starts with that first careful step.