Kentucky’s fertile soil warms quickly, allowing rhubarb planting to begin in late winter. Finding the best time to plant rhubarb in Kentucky is key for a strong harvest. You want to get those crowns in the ground when the soil is workable but still cool.
Rhubarb is a hardy perennial that thrives in Kentucky’s climate. It needs a cold dormancy period, which our winters provide naturally. Plant too late, and the roots may struggle before summer heat arrives.
This guide covers everything you need to know about timing your rhubarb planting. We’ll look at soil temperatures, frost dates, and variety choices specific to Kentucky gardens.
Best Time To Plant Rhubarb In Kentucky
The absolute best time to plant rhubarb in Kentucky is from late February through early April. This window gives the crowns time to establish roots before the heat of late spring.
In western Kentucky, you can start as early as mid-February. In eastern parts, wait until mid-March. The key is to plant when the soil is thawed and workable, but not muddy.
Soil temperature should be between 40°F and 50°F. Use a soil thermometer to check. If the ground is still frozen or waterlogged, wait a week or two.
Why Spring Planting Works Best
Rhubarb needs a chilling period of at least 500 hours below 40°F. Kentucky winters easily provide this. Spring planting lets the plant use that natural cold cycle.
Fall planting is possible but riskier. Young plants may not have enough time to establish before winter freezes. Spring gives them a full growing season to build strong roots.
If you miss the spring window, you can still plant in early fall. But aim for at least six weeks before the first hard frost. That means September planting in most of Kentucky.
Regional Variations Across Kentucky
Kentucky spans USDA hardiness zones 6a to 7a. This affects your planting calendar slightly.
- Western Kentucky (Paducah, Owensboro): Late February to mid-March
- Central Kentucky (Louisville, Lexington): Early March to late March
- Eastern Kentucky (Ashland, Pikeville): Mid-March to early April
- Northern Kentucky (Covington, Newport): Mid-March to early April
Check your local frost dates. The last spring frost in Kentucky ranges from April 1 to April 20. Planting after the last frost is safe, but rhubarb actually prefers cooler soil.
Preparing Your Soil For Rhubarb
Good soil prep makes a big difference. Rhubarb is a heavy feeder and needs rich, well-draining ground.
Start by choosing a sunny spot. Rhubarb needs at least six hours of direct sun daily. Partial shade reduces yield and makes stems thinner.
Test your soil pH. Rhubarb likes slightly acidic soil, between 6.0 and 6.8. Kentucky soil is often acidic, so you may need to add lime.
Steps To Prepare The Planting Bed
- Clear the area of weeds and grass. Rhubarb does not compete well with weeds.
- Dig the soil to a depth of 12-18 inches. Rhubarb roots grow deep.
- Mix in 2-3 inches of aged compost or well-rotted manure.
- Add a balanced fertilizer like 10-10-10 at a rate of 1 pound per 100 square feet.
- Rake the bed smooth and water it well a day before planting.
Raised beds work great for rhubarb. They warm up faster in spring and drain better. This is helpful in Kentucky’s clay-heavy soils.
Choosing The Right Rhubarb Variety
Not all rhubarb varieties perform the same in Kentucky. Some are better suited to our hot summers.
- Victoria: Classic green-stemmed variety. Reliable and disease-resistant.
- Canada Red: Red stems with good flavor. Tolerates heat well.
- Valentine: Bright red stalks. Early harvest variety.
- Riverside Giant: Large green stalks. Very productive in Kentucky.
- Crimson Red: Deep red color. Sweet flavor, good for pies.
Avoid varieties bred for northern climates. They may struggle with Kentucky’s summer heat. Stick with proven performers for our region.
How To Plant Rhubarb Crowns
Rhubarb is usually grown from crowns, not seeds. Crowns are dormant root pieces with a bud at the top. They are available at garden centers in early spring.
You can also buy bare-root plants online. Order them in late winter so they arrive at the right planting time.
Step-By-Step Planting Instructions
- Dig a hole about 12 inches wide and 6 inches deep.
- Place the crown in the hole with the bud facing upward.
- The top of the crown should be 1-2 inches below the soil surface.
- Cover with soil and press down gently to remove air pockets.
- Water thoroughly after planting.
- Space plants 3-4 feet apart. Rhubarb spreads wide.
Do not plant too deep. If the crown is buried too far, it may rot. If too shallow, it may dry out.
Water regularly during the first few weeks. Keep the soil moist but not soggy. Once established, rhubarb is fairly drought-tolerant.
Mulching For Success
Apply a 2-3 inch layer of organic mulch around each plant. Use straw, shredded leaves, or wood chips.
Mulch helps retain moisture and keeps soil cool. It also suppresses weeds that compete with young rhubarb.
In Kentucky’s hot summers, mulch is essential. It prevents the soil from baking and stressing the roots.
Caring For Rhubarb After Planting
Rhubarb needs minimal care once established. But the first year is critical for building a strong root system.
Do not harvest any stalks in the first year. Let all the leaves grow to feed the roots. This ensures a productive plant for years to come.
Water during dry spells. Rhubarb needs about 1 inch of water per week. In Kentucky, summer droughts are common, so supplemental watering helps.
Fertilizing Rhubarb
Apply a balanced fertilizer in early spring each year. Use 10-10-10 at a rate of 1/2 pound per plant.
Side-dress with compost in midsummer. Spread a 1-inch layer around the base of each plant. This provides slow-release nutrients.
Avoid high-nitrogen fertilizers. They produce lots of leaves but weak stems. Stick with balanced or low-nitrogen options.
Dealing With Pests And Diseases
Rhubarb is generally pest-free in Kentucky. But a few issues can arise.
- Rhubarb curculio: A small beetle that damages stalks. Hand-pick and destroy them.
- Slugs and snails: They eat leaves. Use beer traps or diatomaceous earth.
- Crown rot: Caused by wet soil. Improve drainage and avoid overwatering.
- Leaf spot: Fungal disease. Remove infected leaves and improve air circulation.
Good garden hygiene prevents most problems. Remove dead leaves in fall and rotate planting areas every 5-7 years.
When To Harvest Rhubarb In Kentucky
Do not harvest in the first year. Wait until the second year for a light harvest. Full harvests start in the third year.
Harvest season runs from April through June in Kentucky. Stalks are ready when they are 12-18 inches long and firm.
To harvest, grasp the stalk near the base and pull it gently to the side. It should snap off cleanly. Do not cut stalks with a knife, as this can damage the crown.
How Much To Harvest
In the second year, take only 2-3 stalks per plant. Leave at least half the stalks to support growth.
In the third year and beyond, you can harvest up to two-thirds of the stalks. Stop harvesting by early July to let the plant recover.
Never remove all the leaves. The plant needs them to produce energy for next year’s growth.
Extending The Harvest Season
You can force rhubarb for an earlier harvest. Cover the crown with a bucket or forcing pot in late winter. This blocks light and produces tender, pink stalks.
Forced rhubarb is ready 4-6 weeks earlier than normal. It has a milder flavor and is considered a delicacy.
Do not force the same plant two years in a row. It stresses the crown. Alternate between plants if you want early rhubarb each year.
Common Mistakes When Planting Rhubarb
Many gardeners make these errors. Avoid them for a healthy rhubarb patch.
- Planting too deep or too shallow
- Planting in shade or poor soil
- Harvesting too much in the first year
- Overwatering or underwatering
- Using too much nitrogen fertilizer
- Planting too close together
Rhubarb is forgiving, but these mistakes can stunt growth. Follow the guidelines above for best results.
What To Do If You Planted Too Late
If you miss the spring window, do not panic. You can still plant in early fall. Just give the plants extra care.
Water deeply and mulch well. Protect young plants from hot sun with shade cloth if needed.
Fall-planted rhubarb may take an extra year to establish. But it will catch up eventually.
Rhubarb Companion Plants
Rhubarb grows well with certain plants. Good companions include:
- Strawberries
- Beans
- Garlic
- Onions
- Brassicas (cabbage, broccoli)
Avoid planting near potatoes or tomatoes. They compete for nutrients and may spread diseases.
Rhubarb also works well as a border plant. Its large leaves create a striking visual in the garden.
Frequently Asked Questions
Can I Plant Rhubarb In The Summer In Kentucky?
Summer planting is not recommended. The heat stresses young plants. Stick with spring or early fall planting.
How Long Does Rhubarb Live In Kentucky Gardens?
With proper care, rhubarb plants can produce for 10-15 years. Some Kentucky gardens have plants over 20 years old.
Do I Need To Divide Rhubarb Plants?
Yes, divide every 5-7 years in early spring. Dig up the crown and split it into sections with at least one bud each.
What Is The Best Rhubarb Variety For Kentucky?
Canada Red and Victoria are top choices. They handle Kentucky’s heat and produce reliable harvests.
Can I Grow Rhubarb From Seed In Kentucky?
Yes, but it takes longer. Seeds take 2-3 years to reach harvest size. Crowns are faster and more reliable.
Final Tips For Kentucky Rhubarb Growers
Plant at the right time, prepare your soil well, and be patient. Rhubarb rewards you with years of delicious stalks.
Remember that the best time to plant rhubarb in Kentucky is late winter to early spring. Mark your calendar for late February or early March.
With a little effort, you will have a productive rhubarb patch that provides pies, jams, and sauces for years. Enjoy the process and the harvest.
If you have clay soil, consider building raised beds. They warm up faster and drain better, giving your rhubarb a head start.
Water consistently during dry spells. Mulch heavily in summer. Remove flower stalks as soon as they appear to direct energy to the roots.
Rhubarb leaves are toxic to humans and pets. Do not compost them. Dispose of them in the trash or burn pile.
Share your rhubarb with neighbors. One plant produces more than most families can use. It is a generous crop.
Finally, enjoy the process. Rhubarb is one of the easiest perennials to grow in Kentucky. Get it started right, and it will reward you for decades.