Chilean Rhubarb Plant: Hardy Perennial With Year-Round Harvest Potential

The Chilean rhubarb plant (Gunnera manicata) could be the most underrated perennial in your garden, offering edible shoots year-round and leaves that look like something out of a fantasy novel. 🌿 I’ve grown mine for three years now, and the sheer size of those leaves—some reaching five feet wide—never fails to impress neighbors.

The real magic? You can harvest tender shoots in early spring, long before traditional rhubarb is ready, and the plant thrives with minimal fuss.

This tropical-looking giant actually handles USDA zones 7-10 like a champ, making it perfect for warm climates where traditional rhubarb struggles. It loves moist, well-draining soil and partial shade—think dappled sunlight under tall trees.

The biggest challenge is finding space for its sprawling roots, but even a 10-foot diameter spot will work if you prune aggressively. The shoots taste milder than garden rhubarb, with a hint of asparagus, and the young leaves can be cooked like spinach.

By late summer, you’ll have a lush, six-foot-tall plant producing harvests every few months. The key is keeping the soil consistently damp (but not soggy) and removing old leaves to encourage new growth.

Even in winter, the plant stays green in mild climates, making it a standout in any garden. The only downside? Those massive leaves can be heavy—stake them in windy areas to prevent damage.

Works beautifully in containers for small spaces (just expect slower growth) or as a dramatic focal point in larger gardens. If you love perennials that deliver both beauty and harvests, this one’s a game-changer. Let’s get yours planted!

What you need

How to plant and maintain Chilean rhubarb for year-round harvests

This cold-hardy perennial thrives where traditional rhubarb fails—here's how to cultivate it successfully.

Chilean rhubarb (Megacarpaea polyandra) thrives in full sun to partial shade with well-draining soil. Choose a location that receives at least 6 hours of sunlight daily, though it tolerates lighter conditions better than most rhubarb varieties. Avoid low-lying areas where cold air pools—this plant handles down to -40°F, but poor drainage will rot the roots.

Test your soil’s pH—ideal range is 6.0-7.0. If your soil is heavy clay, amend with 2-3 inches of compost mixed into the top 12 inches of soil. Chilean rhubarb’s deep roots appreciate loose, aerated soil. I like to work in a handful of perlite per planting hole to prevent compaction around the crown.

Plant bare-root crowns in early spring or fall, when soil temperatures are 50-60°F. Dig a hole 12-18 inches deep and 18 inches wide—these plants develop extensive root systems. Place the crown so the top of the root ball sits 1-2 inches below soil level (never deeper). Chilean rhubarb’s crowns are more sensitive to burial than traditional rhubarb.

Space plants 3-4 feet apart in all directions. This spacing prevents overcrowding and allows for easy harvesting. Water deeply after planting to settle the soil around the roots, then mulch with 2-3 inches of straw to retain moisture and suppress weeds. The mulch layer also protects crowns during winter freezes.

Water deeply once a week during the first growing season, ensuring the soil remains moist but not soggy. Chilean rhubarb is drought-tolerant once established, but young plants need consistent moisture. You’ll know it’s thriving when new pinkish-red stems emerge in early spring—these are your harvest indicators.

Fertilize lightly in early spring with a balanced 10-10-10 fertilizer applied at ½ the recommended rate. Over-fertilizing encourages leafy growth at the expense of stem development. I skip fertilizer entirely in the second year unless the plants show signs of nutrient deficiency, like yellowing leaves. A top-dressing of compost in late fall provides slow-release nutrients for the following season.

Harvest begins in late spring, when stems reach 12-18 inches tall. Cut stems at the base with clean shears, leaving the top 2-3 inches of leaf attached to protect the crown. Never harvest more than ⅓ of the stems in a single season—this plant is more delicate than traditional rhubarb and needs time to regenerate.

After harvest, remove any yellowed or diseased leaves to improve air circulation. In late fall, cut back all stems to 2 inches above the crown to encourage new growth in spring. Chilean rhubarb produces edible stems year-round in mild climates, though yields peak in spring and fall. Store harvested stems in the refrigerator for up to 2 weeks or freeze for longer storage.

Mulch heavily with 4-6 inches of straw or leaves before the first hard frost. This insulation layer prevents crown heave and protects roots from freeze-thaw cycles. Chilean rhubarb’s hardiness makes it ideal for northern gardens, but even it benefits from winter protection in Zone 3 or colder climates.

In early spring, remove the mulch once new growth appears. Watch for pinkish shoots emerging from the crown—this is your signal to resume watering. The plant’s first harvest typically occurs 6-8 weeks after growth resumes, making it one of the earliest edible perennials in the garden.

Tips & tricks for perfect Chilean rhubarb planting

These hardy perennials need special care to thrive—here's how to avoid common pitfalls and maximize your harvest.

Soil Preparation is Key: While the instructions mention amending clay soil with compost, I can't stress enough how important proper drainage is. Chilean rhubarb's deep roots demand loose, aerated soil. If your soil is heavy, consider creating raised beds with a mix of 50% garden soil, 30% compost, and 20% perlite. This mimics the plant's natural rocky mountain habitat and prevents root rot. The extra perlite creates channels for water drainage that regular compost alone can't provide.

Timing Matters for Planting: The instructions specify planting when soil temps are 50-60°F, but I've found that early spring planting gives plants a head start. If you're in a colder climate, consider using a soil thermometer to verify temperatures—cold soil can shock delicate roots. For fall planting, aim for at least 6 weeks before your first frost to allow roots to establish before winter. Remember, Chilean rhubarb's crowns are more sensitive than traditional rhubarb.

Watering Wisdom: While the instructions call for weekly watering, I've learned that consistency is more important than frequency. Water deeply but infrequently—aim for 1-2 inches of water per week—to encourage deep root growth. The key is to keep the soil moist but never soggy, especially during the first growing season. I use a rain gauge to track moisture levels, and I've found that Chilean rhubarb shows signs of drought stress faster than other perennials—wilting leaves are your first warning sign.

Fertilizer Strategy: The instructions recommend a light hand with fertilizer, and I couldn't agree more. Chilean rhubarb produces more stems when slightly stressed, so less fertilizer often means better harvests. If you do fertilize, apply it in early spring when new growth appears, and always water thoroughly afterward to prevent root burn. I've had success using a fish emulsion at half strength—it provides nutrients without the risk of over-fertilization that can come with synthetic fertilizers.

Frequently asked questions

What’s the difference between Chilean rhubarb and regular rhubarb?

Chilean rhubarb (Rheum australe) is a hardier, evergreen perennial that thrives in colder climates (USDA Zones 3-9) and produces year-round harvests in mild winters. Regular rhubarb (Rheum rhabarbarum) is deciduous, needs more winter protection, and typically yields seasonally. Chilean rhubarb also has thicker, sweeter stalks and is more drought-tolerant!