Gunnera, also galled giant rhubarb, is a plant with fascinating leaves that fits very well in a waterside setting.
General Gunnera facts
Name – Gunnera manicata
Family – Gunneraceae
Type – perennial
Height – 8 feet (2.5 m)
Exposure – full sun
Soil – moist
Foliage – deciduous or evergreen, depending on the climate
Flowering – May to September
Caring for it is easy and it is guaranteed to produce a great decorative impact!
- 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).
- Leaves die off when temperatures drop below 32°F (0°C).
- 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.
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
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.
Smart tip about Gunnera
In fall, use the leaves you have just cut off to protect the stump from the winter cold.