Gunnera, a giant rhubarb with mammoth leaves

Gunnera, also galled giant rhubarb, is a plant with gigantic leaves.

Key Gunnera facts

Name – Gunnera manicata
Family – Gunneraceae
Type – perennial

Height – 8 feet (2.5 m)
Exposure – full sun

Soil: moist – Foliage: deciduous in cold areas – Flowering: end of spring → fall

Caring for it is easy and it is guaranteed to produce a great decorative impact!

Planting Gunnera

In spring. Choose a very moist place, preferably near a pond or body of water.

• Gunnera likes rather rich and moist soil.
• Gunnera needs sun, but tolerates growing in part sun.
• Gunnera doesn’t cope well with strong and/or cool winds.

Propagating Gunnera is performed through crown division in spring, chopping the rhizomes off.

Sowing Gunnera takes place in spring, in nursery pots kept moist until germination has occurred.

• Preparing the seedlings takes a long time (almost 90 days) so be patient.

Pruning and caring for Gunnera

Rather hardy, Gunnera does suffer from freezing if temperatures drop below 14°F (-10°C) (or even a bit warmer if it happens over an extended time period). It helps to winterize the plant properly.

Winter care for gunnera

Leaves die off when temperatures drop below 32°F (0°C). Roots will survive even colder temperatures, but they must be well protected.

• Remove all leaves in fall, snipping them as short as possible.
• Cover the stump with the leaves to protect it against frost and cold winter air.
• Form a tent or a teepee so the leaves stay in place even on windy days.

Watering gunnera

In pots, it’s crucial to water a lot. The soil must stay moist at all times. If ever the soil clump dries out, the plant will have a hard time recovering during the season.

In winter, only water once a month, a little bit, just enough to get the soil a bit moist again.

When planted in the ground, you’ll have to water whenever heat waves hit and during droughts. In time, though, the plant grows deeper roots and you won’t have to water as much.

Potted Gunnera

Growing Gunnera in pots is possible if the following is taken into consideration.

• Soil must be rich, and hence regularly fertilized.
• Find a sizeable pot if you plan to keep your Gunnera for several years.

Roots must be always moist but should not wallow in water or they will rot.

• Provide for a wide water collection dish under your pot, that must always contain water.
• Water regularly without flooding the roots

Learn more about Gunnera

Native to South America, from Brazil, this perennial plant family counts 45 different species, all of them spectacular.

Their leaves are gigantic, and their blooms are too: their flower-studded panicles can be over 5 feet (1.5 meters) tall!

There are no particular requirements to meet when growing them, except for protecting them from the cold in winter and placing them near waterlogged areas.

Although Gunnera is often called giant rhubarb, don’t presume anything: leaves and stems of gunnera are not edible, unlike those of common rhubarb.