Overwintering Rhubarb

In temperate climates, rhubarb generally survives the winter on its own. In fact, the plant needs around 500 hours (around 7 weeks) at 40°F (4 °C) or below to trigger healthy new growth in spring. 

In the fall, allow the remaining leaves to die back naturally before cutting the stems near the base of the plant. The leaves can be added to your compost pile, but should not be left to break down around the plant.

While rhubarb is hardy down to -30°F (-34°C), extra protection can help in regions with particularly long or harsh winters, such as USDA Zone 4 or mountainous areas. Applying a thick layer of mulch after the leaves have been removed provides insulation against freezing temperatures. During my time in Idaho, I found that covering rhubarb with a pot throughout the winter helped temper the colder nights and protected tender shoots from late frosts, snow, and ground upheaval.

In warm desert climates, overwintering is more challenging. Unless winter temperatures regularly drop below 40°F, rhubarb crowns may struggle to survive. In the U.S., this includes the high desert regions of California and much of Arizona. Planting rhubarb in pots that can be moved to cooler locations, such as a garage or shed, can help the plant survive.

General Plant Care

Young rhubarb plants—those less than two years old—require careful watering during dry spells to establish deep, vigorous roots. Once established, care mainly involves removing flower stems to encourage more leaf growth, clearing away faded leaves, and dividing overcrowded clumps.

Rhubarb should be watered when the soil around it becomes dry or the leaves show signs of stress. These hardy plants like to be kept damp, but not wet. If the summer is particularly hot and dry, growth will slow down, and the plant may enter a dormant state for the rest of the season.

Spring mulching is highly beneficial. You should apply a 2½-inch deep ring of organic mulch around each plant each year, extending roughly a foot wide. This helps retain soil moisture, suppress weeds, and maintain a stable, fertile soil environment.

Rhubarb occasionally produces flowering stems in spring or summer. Removing them promptly prevents the plant from weakening and reduces the chance of bolting. Flowering is more likely after wet summers, excessive nitrogen feeding, or in older plants that haven’t been divided for several years.

Dividing Mature Plants

Dividing rhubarb is a satisfying way to rejuvenate plants and provide extra crowns to share. This is usually done after five years, though overcrowded or slow-growing plants may benefit from earlier division.

The best time to divide rhubarb is when the plant is dormant, typically between mid-autumn and early spring. Dig up the entire crown carefully, then split it into sections using a sharp knife or hori-hori.

Each division should include plenty of roots, a portion of the rhizome, and at least one bud. Outer sections are generally healthier than older inner sections, while weak or diseased pieces should be discarded. Replant the divisions the same day if possible, spacing them about three feet apart.

Harvesting Rhubarb

Rhubarb should not be harvested in its first year so that it can establish a strong root system. Light harvesting can be done in the second year, but full production really begins in the third year. From this point, up to one-third of the stalks can be removed at a time, typically from April or May, for around 10-14 weeks. Always leave enough leaves on the plant so it can photosynthesize and maintain healthy growth.

Select stems that are about a foot long with freshly unfurled leaves. To harvest, grip the base with your thumb on the skyward side and fingers beneath, then gently pull the stalk from the ground. Avoid cutting or snapping stems, which can damage the crown or introduce rot.

Harvested rhubarb keeps in the refrigerator for up to two weeks, or it can be frozen after being chopped into small pieces. Remember, only the stalks are edible—leaves contain oxalic acid and should be composted or discarded safely.

Forcing Rhubarb

Rhubarb stems naturally grow towards the light, a bit like sunflowers. Being a very vigorous plant, this adaptation can be maximized by growing the rhubarb in near darkness.

To force rhubarb, you will need a crown that has been in your garden for at least 1-2 years, and is healthy and well-established. As the heavy winter frosts begin to ease, cover the crown to exclude light, which encourages tender, sweet stems.

Forced rhubarb is generally sweeter and juicier than normal rhubarb.

There are three main steps:

1. Mulch the rhubarb with fresh, rich mulch. Form a generous donut right around the crown, making sure the crown itself is only lightly covered. 
2. To cover the crown to exclude light, you will need a large, opaque object. A wide 5-10 gallon-sized pot is excellent, or a kitchen dustbin. If it has drainage holes in the pot already, tape them over using heavy-duty waterproof tape. You can also buy dedicated rhubarb cloches.
3. Cover the mulched rhubarb with the bin, and water the plant heavily once a week. The warmth from the decomposing mulch will feed and wake the plant from dormancy. 

After 5–8 weeks, you should have fresh, tender stems about 1 ft long. Harvest gently, then uncover the plant once the risk of frost has passed. Lightly mulch again and allow it to rest for the remainder of the year—don’t harvest forced plants again until the next season.

Wrapping Up

Planting your rhubarb at the right time, caring for it through the seasons, and then dividing it when it gets mature will give you plants that can last over 15 years. One final tip from us is to stagger your plantings. Having plants of different ages means you will always have rhubarb ready to harvest, while some are resting after being divided or forced, or are freshly planted.

Happy growing, and happy eating!

More so than in temperate climates, it’s vital to watch the weather. Extreme heat spells or cold snaps require forethought to protect your plants, and site selection is even more important. These tips cover key points for hot and cold climates, and how you can grow rhubarb successfully.

Rhubarb in Hot, Arid Climates

Rhubarb can grow in hot, dry climates such as Arizona, the high deserts of California, and parts of inland Australia, but it requires some adjustments to survive the intense summer heat while still receiving enough winter chill.

1. Timing and Seasonality Plant crowns in late fall (October–November) to take advantage of cooler temperatures and help roots establish. Light harvesting can begin in late winter to early spring, before the intense summer heat arrives. Once temperatures climb above about 85°F (29°C), rhubarb will naturally go dormant. Forcing it to grow during midsummer can stress the plant and reduce its lifespan.

2. Light and Shade Management Rhubarb thrives with morning sun and afternoon shade. In extremely hot areas, protect leaves from sun scorch using shade cloth, pergolas, or by planting near structures that block the afternoon sun. In containers, plants can be moved to shaded patios or under trees during peak heat; putting pots on wheels makes this easier.

3. Mulching and Soil Care Apply 3–4 inches of organic mulch around the crown to insulate roots, retain moisture, and reduce soil temperature. Mulch can lower soil temperature by around 10°F, keeping roots cooler in scorching summer heat.

4. Container Planting Options Deep pots (at least 2 ft wide by 2 ft deep) are highly effective. Containers allow you to relocate plants for shade, and the soil mix can be tailored for drainage and fertility. Container soil will need yearly replenishment with compost as hotter temperatures often lead to quicker nutrient leaching.

5. Summer Dormancy and Winter Chill During summer dormancy, rhubarb leaves usually wilt or die back entirely. Water lightly to keep the soil damp but not wet. In regions where winters remain warm (e.g., parts of inland Australia), potted rhubarb can be moved to a cool space around 40°F / 4–10°C for 6–8 weeks to simulate dormancy and trigger spring growth.

6. Watering Considerations Water deeply and regularly to encourage robust root growth, making sure to water below the leaves so it soaks into the soil. The soil should be damp but not soggy. Tools like Ollas can provide steady moisture and cool soil conditions, though they must be removed or protected during frost.

7. Wind Care Hot, desert winds can desiccate leaves quickly. If you live in a flatter, more open area, watch the winds and provide protection against the prevailing winds. Shade cloth fixed vertically is an excellent wind screen.

With careful management of light, mulch, water, and timing, rhubarb can thrive in hot, arid climates. Because rhubarb needs winter chill to survive as a perennial, plants in these regions may last 2–3 years rather than the usual 5+, which is normal. Using large pots gives flexibility to move plants to cooler spots during winter or summer.

Rhubarb in Colder Climates

In colder regions, rhubarb is extremely hardy, but extra protection ensures crowns survive harsh winters and produce strong harvests.

1. Mulching and Winter Cover After leaves die back in fall, apply a thick 4–6 inch layer of mulch around the crown to insulate against freezing temperatures. Straw, leaf litter, or compost works well. In very harsh winters (USDA Zone 4 or mountainous areas), cover crowns with burlap, a cloche, or even a large pot to protect young shoots from late frosts and snow. Mulch also helps prevent frost heaving, where crowns lift from the soil during freeze-thaw cycles.

2. Site Selection Choose a sunny location with well-draining soil. Cold air can settle in low spots, so slightly elevated planting sites help protect crowns from frost. Small mounds are ideal in frost-prone areas.

3. Forcing Rhubarb in Cold Climates Forcing is ideal for early spring harvests. Use the same mulch-and-cover method as in temperate climates, ensuring crowns have been established for at least 1–2 years. Darkness encourages tender, sweet stems for early desserts (more on harvesting and forcing in Part 3).

4. Watering Water sparingly during winter dormancy. Excess moisture combined with freezing temperatures can lead to crown rot. Resume watering in spring as soil thaws and growth begins, or observe soil moisture—sometimes no extra water is needed if rainfall is sufficient.

5. Longevity With proper winter protection, rhubarb crowns can live for 10–15 years or more. Dividing overcrowded crowns in late winter or early spring rejuvenates plants and maintains productivity.

Growing rhubarb in more extreme climates requires planning, but with attention to temperature, predicted rainfall, and seasonal adjustments, you can enjoy delicious stems year after year. Even if harvests are smaller or plants behave more like annuals in hot regions, foresight ensures your rhubarb thrives for seasons to come.

In Part 3, we’ll go over general care tips for all climates, harvesting advice, and additional ways to grow rhubarb.

In the first part of this series, we’ll discuss popular varieties and go over how best to plant rhubarb.

Popular Varieties

There are dozens of rhubarb cultivars, each created for different reasons. Some grow more quickly, others are sweeter, and some are suited to more challenging environments. If you live in a temperate environment, such as the UK, you will find that most, if not all, varieties will grow with good success. 

Choosing varieties more suited to your growing needs and conditions will give you healthier plants that produce more rhubarb stalks for you each year.

Varieties for Warm Climates

• MacDonald Rhubarb — Developed in the 1920s, this variety is less tart than most and shows excellent resistance to heat, wilt, and root rot. Performs best up to Zone 8 but can continue beyond that with attentive care.
• Canada Red Rhubarb — A compact variety with shorter, tender stems and a naturally sweet flavor. Prefers cooler conditions up to Zone 8 but can be grown as an annual in warmer zones with partial shade and consistent watering.
• Crimson Red (Cherry Red) — Known for its striking deep red stalks and good heat tolerance. While not ideal for desert zones, it performs well in areas with warm summers and mild winters.

Varieties for Temperate Climates

• Timperley Early — One of the first varieties ready for harvest, often by early spring. Perfect for gardeners eager to enjoy rhubarb pies and crumbles while other crops are still waking up.
• Sutton — With vivid red stalks and a well-balanced tartness, Sutton is both ornamental and productive. Performs best in steady, temperate conditions without extreme heat or cold, and is a good option for smaller gardens.
• Champagne — A classic English variety with slender, pinkish stems and a delicate flavor. Particularly good for forcing (growing in darkness to produce early, tender stalks) and favored by traditional kitchen gardeners.

Varieties for Cold Climates

• German Wine — A hardy selection with strong, thick stalks that hold up well in late frosts. Has a deep, rosy hue and a pleasant balance of sweetness and acidity, making it a favorite for preserves and baking.
• Valentine — Noted for its vivid crimson color and resilience, Valentine tolerates very cold winters and returns reliably each year. Less stringy than some other varieties, making it excellent for cooking.

All-Around Variety

• Victoria — A dependable heirloom and one of the oldest named varieties, Victoria produces long, greenish-red stalks with a mild flavor. Forgiving of different soils and weather patterns, it tolerates moderate cold and, with some extra shade, can survive hot summers. It’s also less prone to bolting than most other varieties.

How to Plant Rhubarb

Rhubarb can be planted as dormant crowns (typically sold November–March) or as potted plants later in the spring. Dormant crowns are ideal for establishing a strong root system, while potted plants give a head start on growth.

Fall is the ideal time to plan your rhubarb garden, giving you time to prepare the planting site and source quality crowns. This allows you to prepare the planting site and find the best places to get your rhubarb crowns from. Many garden centers will sell them; however, you can always ask a neighbor if they have any crowns ready to divide.

Planting Steps:

1. Prepare the Soil: Choose a location with rich, fertile soil that receives plenty of sun. Loosen the soil to a depth of 12–18 inches and amend with compost or well-rotted material such as leaf mold.
2. Dig the Hole: Make a hole slightly wider than the root system (about 1.5 times the crown’s width) and deep enough so the base of the buds sits just above the soil surface.
3. Planting: Place the crown or potted plant in the hole, spreading roots gently without bending or crowding them. For crowns, ensure the buds point upward. Backfill the hole with soil and compost mix, firming gently.
4. Mulching: Apply a light donut-shaped mulch ring around the crown (1 inch deep, up to 1 ft wide) to retain moisture, suppress weeds, and stabilize soil temperature. The mulch should be pulled about an inch back from the crown to prevent rot.
5. Watering: Water deeply immediately after planting to help roots settle. For the first few weeks, maintain consistent moisture without waterlogging the soil.
6. Spacing: Space plants 75–90 cm (30–35 in) apart to allow room for the plants to mature. Overcrowding can reduce airflow, increasing disease risk. Varieties vary in size, so check how large your plants will get before you plant; you may have to increase the spacing.
7. Container Planting: If using pots, choose a container at least 2 ft wide and 2 ft deep per plant. This allows for controlled soil conditions, easier relocation to shade, and better heat management in hot climates.

In the next section, we’ll cover how to select the perfect site for rhubarb.

Choosing a Planting Location

Rhubarb thrives in sunny locations, although it will tolerate some shade quite well. The soil should be rich and fertile and hold water well without becoming waterlogged. If your soil is clay-heavy or has poor drainage, amend it with mulch and compost to improve porosity and create consistent air pockets.

Rhubarb stems are easily damaged by late frosts, unless you choose a late-cropping variety that emerges later into the spring. Sites that get the first sun of the day are ideal, as morning sun helps burn off frost and overly heavy dew quickly. Slightly elevated spots are also preferable, since cold air can settle in low areas and increase the risk of frost damage. Planting rhubarb in small mounds can help.

Very cold or very hot environments will have slightly different planting needs, which we will cover in part 2.