Many gardeners in warmer regions think rhubarb is impossible to grow, but with the right approach, you can learn how to grow rhubarb in the south. This southern climate gardening guide will show you the specific techniques needed for success.
Rhubarb is a perennial vegetable cherished for its tart, flavorful stalks. It traditionally thrives in cool climates with freezing winters. Southern heat and humidity present real challenges, primarily because rhubarb requires a significant chill period to break dormancy and produce well.
But don’t be discouraged. By selecting special varieties and modifying your gardening practices, you can enjoy a homegrown rhubarb harvest. The key is managing its need for chill and protecting it from intense summer heat.
How to Grow Rhubarb in the South – Southern Climate Gardening Guide
This guide breaks down the process into manageable steps. We’ll cover everything from choosing your plants to year-round care. Let’s get started.
Understanding Rhubarb’s Needs vs. Southern Reality
Rhubarb’s natural cycle conflicts with southern seasons. It needs temperatures below 40°F for about 500-700 hours in winter. This chill tells the plant to go dormant and reset for spring growth.
Summers in the south are long, hot, and humid. Rhubarb plants can suffer from crown rot, bolt (go to seed), and simply stop growing. The goal is to mimic its preferred conditions as much as possible.
Choosing the Right Rhubarb Variety
Your single most important decision is variety selection. Standard red types like ‘Canada Red’ often struggle. You need a “low-chill” variety.
- ‘Victoria’: A green-stalked variety known for being more heat-tolerant than most. It’s a reliable option.
- ‘Glaskin’s Perpetual’ or ‘Timperley Early’: These are often recommended for warmer zones as they require less winter chill.
- ‘Chipman’s Canada Red’: Some southern gardeners report better luck with this type compared to other reds.
Always source crowns (the root piece) from a reputable nursery in the fall. Ask them for their most heat-tolerant stock. Starting from seed is not recommended, as it adds years to your wait for a harvest.
The Perfect Planting Site and Soil
Location is critical. You must provide relief from the afternoon sun.
- Sunlight: Aim for a spot that gets full morning sun but is shaded during the hottest part of the afternoon (from about 2 PM onward). Dappled sunlight all day under a tall tree can also work.
- Soil: Rhubarb demands excellent drainage to prevent crown rot. Amend your native soil deeply with lots of compost or well-rotted manure. The ideal soil is rich, loamy, and slightly acidic to neutral (pH 6.0-7.0).
- Raised Beds: This is often the best solution. They provide superior drainage and allow you to control the soil mix. Build your bed at least 12 inches deep.
Step-by-Step Planting Instructions
Timing is different in the south. Plant in early fall (October-November). This gives the crown time to establish roots in cooler weather before the next summer’s heat.
- Prepare a planting hole or bed that is wide and deep, mixing in generous amounts of compost.
- Place the crown so the buds (or “eyes”) are 1-2 inches below the soil surface. If the crown has long roots, spread them out.
- Space multiple plants at least 3 feet apart. They need good air circulation.
- Water the crown in thoroughly after planting to settle the soil.
- Apply a thick layer of mulch (straw, shredded leaves, or pine bark) to keep roots cool and retain moisture.
Ongoing Care Through the Seasons
Your care calendar will look different than a northern gardener’s.
Watering and Feeding
Consistent moisture is vital, but wet foliage causes disease. Water deeply at the base of the plant, aiming for about 1 inch per week. A soaker hose is ideal.
Feed your rhubarb in early spring as growth begins and again in early fall. Use a balanced organic fertilizer or a top-dressing of compost. Avoid high-nitrogen fertilizers, which promote weak, leafy growth.
Mulching and Summer Protection
Mulch is your best friend. Maintain a 3-4 inch layer year-round. In summer, it keeps the soil cool and moist. In winter, it insulates the crown from temperature swings.
If a heatwave is forecast, consider providing temporary shade with a shade cloth. This can prevent the leaves from wilting and scorching.
The Critical Winter “Chill” Strategy
To compensate for mild southern winters, you need to trick the plant. After the first hard frost blackens the leaves, cut the foliage back to the ground.
Then, do not mulch heavily immediately. Allow the plant to experience as many chill hours as possible. You can apply a heavier mulch layer in late December or January if a hard freeze is expected. Some gardeners even place ice packs around the base periodically in winter.
Harvesting Your Southern Rhubarb
Patience is essential. Do not harvest any stalks in the first year. This allows the plant to build a strong root system. In the second year, you can harvest lightly for 2-4 weeks in spring.
By the third year, you can harvest for 8-10 weeks, but stop by mid-June. Always harvest by twisting and pulling stalks from the base; don’t cut them. Never remove more than one-third to one-half of the plant’s stalks at one time. And remember, the leaves are poisonous—always remove and compost them.
Common Problems and Solutions
- Crown Rot: Caused by soggy soil. Ensure perfect drainage and avoid watering the crown directly.
- Bolting (Flowering): When a flower stalk appears, cut it off immediately at the base. Bolting is triggered by heat and stress, and it diverts energy from stalk production.
- Spider Mites: These pests love hot, dry conditions. Blast leaves with water regularly or use insecticidal soap if infestations occur.
- Weak, Thin Stalks: Usually a sign of too much heat, too little chill, or nutrient-deficient soil. Review your feeding and site conditions.
Long-Term Maintenance and Division
Every 5-6 years, your rhubarb clump may become overcrowded. The best time to divide is in the fall when the plant is dormant. Dig up the entire crown and use a sharp spade to cut it into sections, each with at least 2-3 buds. Replant the healthiest pieces, and give away or compost the old, woody center.
FAQ: Growing Rhubarb in Warm Climates
Can I grow rhubarb in pots in the South?
Yes! Container growing is an excellent strategy. Use a large pot (at least 20 gallons) with drainage holes. You can move it to a shadier, cooler spot in peak summer and even into a fridge or unheated garage for a few weeks in winter to supplement chill hours.
What is the best zone for growing rhubarb in the South?
With extreme care, gardeners in USDA zones 7 and 8 can have success. Zone 9 is very challenging and often requires treating rhubarb as an annual or using specialized pot-and-chill techniques. It’s rarely successful in Zone 10.
Why are my rhubarb stalks green and not red?
Color is mostly variety-dependent. Many heat-adapted varieties like ‘Victoria’ have green stalks with a pink blush. Stalk color does not effect flavor. Lack of red pigment is not a sign of a problem.
Should I fertilize my rhubarb in the summer?
No. Avoid fertilizing during the hot summer months. This can encourage new growth that is vulnerable to heat stress. Stick to spring and early fall feeding schedules.
Growing rhubarb in the south requires extra attention, but the reward of fresh, homegrown stalks is worth the effort. By selecting a tolerant variety, providing afternoon shade, ensuring perfect drainage, and managing its chill requirement, you can defy the odds. Start with healthy crowns this fall, and you could be harvesting your own tangy rhubarb in the springs to come.