Chilean Rhubarb Plant: Hardy Perennial for Cold-Climate Gardens

Transform your garden with the Chilean rhubarb plant, a drought-tolerant superstar that flourishes where most perennials falter. I first spotted this plant in a Zone 3 garden, its deep green, sword-like leaves standing tall even after a late frost.

Unlike traditional rhubarb, it doesn’t bolt in summer heat or demand rich soil—just good drainage and patience.

The real magic happens in its second year, when sturdy stalks emerge that can reach 3 feet tall—perfect for ornamental borders or even edible experiments (though not as sweet as garden rhubarb).

Plant it in full sun, water once a week after establishment, and watch it spread slowly but surely. My plants now divide every 3-4 years, giving me free plants to share.

What makes this perennial special is its zero-fuss nature. No pests bother it, deer ignore it, and it handles -40°F winters with ease. The only challenge? Waiting for those first edible stalks—year one is all about roots, but by year two, you’ll have a harvest.

I’ve used mine in jams (with caution—it’s tart!) and as a striking focal point in my rock garden.

Best for cold-climate gardeners who want low-maintenance beauty with a side of resilience. Start with one plant, and you’ll soon have a self-sustaining patch that outlasts most perennials. Here’s how to get yours growing strong from day one.

What you need

Step-by-step instructions for planting and cultivating Chilean rhubarb

This cold-hardy perennial thrives in harsh climates with minimal fuss once established.

Chilean rhubarb (Gunnera manicata) demands space—each plant spreads aggressively, so choose a location with at least 6 feet of diameter in all directions. The ideal spot receives partial shade, especially in hotter climates, where afternoon sun can scorch its broad leaves. I always test the soil pH first; this plant prefers 6.0-7.0 and struggles in alkaline conditions.

Amend heavy clay soil with 2-3 inches of compost mixed into the top 12 inches of soil. Chilean rhubarb’s massive roots need loose, well-draining soil to prevent rot. If your soil drains poorly, incorporate sand or perlite to improve aeration. Avoid disturbed ground—this plant thrives in undisturbed, fertile soil where its roots can spread undeterred.

Purchase bare-root crowns or divide mature clumps in early spring before new growth begins. Dig a hole twice as wide as the root ball but only as deep as the top of the roots—planting too deep suffocates the crown. Space multiple plants 8-10 feet apart to prevent competition.

Place the crown in the hole, ensuring the buds (eyes) face upward—they’ll emerge as new shoots. Backfill with native soil, tamping gently to eliminate air pockets. Water deeply immediately after planting to settle the soil and encourage root contact. Avoid fertilizing at planting; the disturbed soil provides enough nutrients initially.

Keep the soil consistently moist for the first 6-8 weeks—Chilean rhubarb’s roots are shallow and sensitive to drought. Water deeply 2-3 times per week until rainfall replaces this effort. You’ll know it’s enough when the top 2 inches of soil feel damp but not soggy.

Apply a 3-inch layer of organic mulch (like shredded bark or straw) around the base, keeping it 6 inches away from the crown to prevent rot. Mulch conserves moisture, regulates soil temperature, and suppresses weeds—critical for this fast-growing perennial. Replenish mulch annually as it decomposes.

Chilean rhubarb grows rapidly in its first season, producing large, lobed leaves that can reach 5 feet in diameter. Remove any yellowed or damaged leaves promptly to redirect energy to new growth. Never prune more than one-third of the foliage at once—this plant stores energy in its roots and can’t recover from heavy pruning.

Watch for flower stalks in spring; pinch them off immediately. While ornamental, they drain energy from the plant and reduce leaf production. If left unchecked, a single plant can produce dozens of flower stalks, weakening the crown. Harvest leaves sparingly in the first year to avoid stressing the root system.

Chilean rhubarb is extremely cold-hardy (USDA Zones 3-9), but young plants benefit from extra protection in their first winter. Apply a 4-inch layer of mulch in late fall, covering the crown completely. This insulates roots from freeze-thaw cycles, which can heave the plant out of the ground.

In early spring, remove old mulch and inspect the crown for damaged or dead fronds. Trim these back with sterilized pruners, then add a balanced fertilizer (10-10-10) at half-strength when new shoots emerge. Avoid heavy fertilizing—this plant grows best in moderately fertile soil and overfeeding leads to excessive leaf growth at the expense of root vigor.

Tips & tricks for perfectly cultivating Chilean rhubarb

These essential strategies will help you maximize your Chilean rhubarb's potential while avoiding common pitfalls that can stunt its growth or even kill it.

Soil Preparation is Non-Negotiable: The 2-3 inches of compost mixed into the top 12 inches of soil isn't just recommended—it's crucial. I've seen Chilean rhubarb fail spectacularly in unamended clay soil where roots couldn't establish properly. For even better drainage, consider adding a handful of perlite to the bottom of the planting hole before adding your crown. This creates a natural barrier that prevents waterlogging, which can rot those massive roots.

Planting Depth Determines Success: Remember when I mentioned planting only as deep as the top of the roots? This isn't a suggestion—it's a survival technique. The crown needs to breathe, and planting too deep suffocates it. I once watched a beginner bury a crown 4 inches deep, and by summer, that plant was struggling to emerge. Mark the planting depth on your shovel handle if you need to visualize it—this plant's roots are sensitive to being smothered.

Watering Wisdom for Shallow Roots: Those first 6-8 weeks of consistent moisture are critical because Chilean rhubarb's roots are shallow and spread wide. I recommend using a moisture meter to check the top 2 inches of soil—it should read damp but not soggy. If you're watering deeply 2-3 times per week and still seeing wilting, your soil may be compacting. Try using a soaker hose to deliver water directly to the root zone without disturbing the soil surface.

Mulch Matters More Than You Think: The 3-inch layer of organic mulch isn't just decorative—it's a protective barrier. I've seen Chilean rhubarb plants in full sun with inadequate mulch develop brown, crispy leaf edges by midsummer. Keep that mulch 6 inches away from the crown to prevent rot, and remember to replenish it annually. In hot climates, consider adding a second layer in peak summer months to protect those massive leaves from heat stress.

Frequently asked questions

Is Chilean rhubarb edible, and how does it taste compared to regular rhubarb?

Yes, Chilean rhubarb (Rheum australe) is edible and often considered more flavorful than its European cousin! It has a tangier, slightly sweeter taste with less tartness, making it a favorite for pies, jams, and stews. Just like regular rhubarb, it’s best cooked—never eaten raw due to oxalic acid.

How cold-hardy is Chilean rhubarb, and can it survive winter in my zone?

This plant is extremely cold-tolerant, thriving in USDA zones 3–8 (as low as -30°F/-34°C!). It’s a perennial that goes dormant in winter, so mulch around the base in late fall to protect roots. No special winter care is needed beyond that—it’ll bounce back in spring!

How do I tell if my Chilean rhubarb is healthy or struggling?

Healthy plants have large, vibrant green leaves and sturdy stems. Watch for these red flags:

• Yellowing leaves: Often a sign of overwatering or nutrient deficiency (try compost or balanced fertilizer).
• Wilting or mushy stems: Indicates root rot—improve drainage immediately.
• Pests like aphids: Spray with soapy water or introduce ladybugs for natural control.

How long does it take for Chilean rhubarb to produce edible stalks?

Patience is key! Established plants (2+ years old) yield the best harvests, but you might see small stalks in the first year. For faster results:

• Plant crowns in early spring for a head start.
• Fertilize lightly in early spring with compost or 10-10-10.
• Avoid harvesting until the plant is at least 2 feet tall.

Can I grow Chilean rhubarb in containers, or does it need a garden bed?

While it prefers deep, well-draining soil in garden beds, containers can work if they’re at least 18–24 inches deep and wide. Use a mix of potting soil and compost, and place the pot in full sun. Just know: container-grown plants may produce fewer stalks and need more frequent watering.

What’s the best way to propagate Chilean rhubarb?

The easiest method is dividing mature clumps every 3–4 years:

1. Dig up the plant in early spring or fall.
2. Separate crowns with at least 3–4 healthy leaves per division.
3. Replant divisions 18–24 inches apart.

Wrapping up and next steps

The Chilean rhubarb plant is a cold-hardy, low-maintenance gem for gardeners in chilly climates—offering striking foliage, edible stalks, and resilience that few perennials can match.

Whether you’re drawn to its ornamental beauty or its culinary potential, this plant is a fantastic addition to any garden, thriving with minimal fuss once established.

Ready to grow your own? Start by gathering your supplies, choosing the right spot, and following the planting steps. Soon, you’ll be harvesting vibrant stalks or admiring its bold leaves year after year! 🌱