Gunnera manicata (Giant Chile rhubarb) Growing Gunnera in the UK
If you want to grow a plant with the largest leaves possible, then it has to be Gunnera manicata – Giant Chile rhubarb (G. manicata), an absolute essential for the exotic garden that is, if you have enough room! There is a valley with swaths of them growing to perfection at Abbotsbury Gardens in Dorset, a sight to behold. It is easy to divide and split gunnera to cover a greater area.
Gunnera is a very dramatic, clump-forming herbaceous perennial with the biggest leaves that can be grown outside in the UK. This Goliath of a plant is indigenous to regions from Coloumbia to Brazil, growing from 1.8-3m high and 3-4m wide, with enormous rhubarb-like, rounded, prominently veined, sharply toothed, deep green leaves that are spiny underneath and anything up to 2-2.5m across, on prickly stalks up to 2.5m long.
In early summer tiny red flowers are formed on wide, erect spikes 1-1.8m tall. Hardy to-15° C and probably lower with a good mulch.
Is Gunnera Invasive in the UK, and why remove the flowers?
We have an extensive Gunnera grow guide for those interested, and other articles covering topics such as the best time to divide gunnera, whether gunnera is poisonous or toxic to dogs, whether you should be worried about Gunnera being invasive and when to remove the flower spikes, whether gunnera is part of the rhubarb family or how to over winter gunnera. We also cover whether gunnera can be grown in pots and finally the best places to buy gunnera in the UK.
When cut down by frost, place the old leaves over the crowns, to protect them from prolonged freezing periods. It can also be grown in a very large container though it will be smaller in stature. Gunnera is non toxic to dogs.
Common Name: Giant Chile rhubarb Although nothing to do with rhubarb!
Latin Name: Gunnera manicata
Tenderness Rating: Hardy
Ease of growing: Easy
Position: Full sun to dappled shade
Soil Condition: Moisture retentive fertile soils – It works well as a pond marginal
What is a Gunnera?
It is often referred to as a giant rhubarb, Chilean rhubarb, and sometimes dinosaur food. It has short and stout rhizomes as stems and broad umbrella-shaped leaves up to 6 feet wide. Its leaves are shaped like rhubarbs with 4-6 lobes and hairy bottoms
It blooms little green flowers in the summer, followed by tiny red fruits that are dispersed by birds to other patches of land close by.
Gunnera is a herbaceous plant that does not co-exist with other plants. It forms large thick patches that other plants cannot grow into, oftentimes overgrowing whatever plant in these surroundings.
What types of Gunnera are there?
Gunnera Manicata
Gunnera manicata
Gunnera manicata is a giant Brazilian rhubarb with large distinctive leaves that are round kidney shaped and is ideal for an architectural plant. Its leaves grow up to 6 feet in diameter while its rhizome stems can extend up to 10 feet. During summer, its leaves gunnera manicata produces conical-shaped pannicles that consist of tiny red-green florets. These extend up to 3-5 meters high.
Gunnera manicata are easily distinguished by their leaves that sit on top of prickly rhizome stems. The leaves are large, palmately lobed with prominent veins and sharply toothed. This creates a dramatic landscape and that is why it is a popular gardener’s choice for large gardens.
Gunnera Tinctoria
Gunnera Tinctoria also called Chilean rhubarb is a flowering species of the Gunnera plant native to Southern Chile. It is an ornamental plant in its origins but considered an invasive species in some parts of Europe and the US. Its prominently veined leaves are large, deeply lobed, and thorny sit on top of short prickly rhizome stems. At maturity, its leaves are 3 inches wide, and it reaches a height of 6 feet. It thrives well in moist organically rich soil and is a great architectural plant. It blooms in the summer to produce small dull-red flowers followed by tiny round orange fruits. It is an aquatic herbaceous plant and looks best when grown close to a pond or in a bog garden.
Gunnera Magellanica
Gunnera magellanica is a creeping species of the gunnera plant also called Devil’s strawberry. Unlike the large gunnera plants, gunnera magellanica creates a dense ground cover with its round to kidney-shaped glossy leaves. Its leaves are only about 3 inches wide, and they grow to a height of 8 inches tall and spreads quickly creeping over moist soil. The leaves wither during winter but begin springing out from March. By summer it begins to produce unnoticeable tiny green flowers followed by small round orange fruits.
Gunnera Perpensa
Gunnera perpensa is the only member of the gunnera family that has been recorded to originate from Africa. It grows close to water, at creeks banks, ponds and small lakes because its roots need to be embedded in the moist soil that is found on the banks of water bodies. Its hairy leaves are a shade of dark blue and green, large and kidney shaped. It blooms tiny pink and reddish-brown flowers on a long spike that extends above its leaves between September and February. It is one of the few gunnera plants that have known medical uses.
Where to buy Gunnera for sale in the UK
If you are looking for UK suppliers for Gunnera plants for sale, have a look at our list below of suppliers in the UK that currently have stock of Gunnera plants available to buy right now. Get these guys in the ground ASAP and get them well watered!
Growing and Caring For Gunnera
Gunnera plant growing conditions are not complicated but rather very simple. It is a perennial hardy plant so it can do well on its own. The most important point to note when growing any gunnera plant is to take note of their soil and water requirements.
The best planting spot for gunnera plants is a low ground with rich organic soil that is close to the water and gets full sunlight. Gunnera plants love moisture so planting it close to a water body where it will be constantly saturated is a great idea.
Gunnera is a heavy feeder so remember to have a steady supply of compost, organic matter, and sometimes fertiliser.
Gunnera is a large perennial plant native to South America but now popularly grown in other places around the world including New Zealand and the UK. It is named after the renowned Norwegian botanist Johan Ernst Gunnerus even though it was brought to Europe by JJ Linden, a Belgian horticulturist.
Growing Gunnera In Pots
Although Gunnera plants are gigantic plants that need a lot of space, they can still be grown in pots from the gunnera seeds. The germination period could be as short as 14 days or as long as 90 days but the most important thing to remember is that patience is key.
Planting pot: Since most species of the gunnera plant usually grow very large, you need to select a big enough pot for their roots to be able to spread freely because this will affect their overall size.
Soil and moisture: Just like the gunnera that is grown outdoors requires organically rich soil with lots of moisture, an indoor potted gunnera plant needs the same. You can get soil that is mixed in a ratio of 50:50 with compost.
Water: Gunnera loves water and moisture. Where the roots of other plants will ordinarily rot, gunnera root will not. For potted plants, you can place a dish filled with water below your pot to always keep the environment moist. While the plant can survive with lots of water, leaving the roots submerged in water will eventually hurt the plant.
How To Control Gunnera
Most species of the gunnera plant are invasive, so they can easily overshadow your garden. They grow in dense patches and can shade out other plants growing in the area. You can control the spread of a gunnera plant by pulling out seedlings and plants in small patched. You will need to ensure that all fragments of the rhizome, flower heads, and seeds are disposed of properly.
What is the difference between Gunnera manciata and Gunnera tintoria?
Gunnera tinctoria leaves are more rounded and deeply lobed than that of Gunnera manicata and its leaf stalks are shorter as well. The flowering spike of Gunnera tinctoria is shorter and its spikes smaller and less open than those of Gunnera manicata.
Can gunnera be grown from seed?
There are several propagation methods for gunnera and growing it from the seeds is one of the easiest methods.
How do you care for gunnera in winter?
During winter, protect small plants from winter by using dead leaves to cover them.
What growing conditions are needed for gunnera in the UK?
The best growing conditions for gunnera is in moist, organically rich soil in a sheltered spot in full sun.
How big does gunnera get?
The rhizome stem can extend as high as 2.5m while it grows as wide as 4m. They are very broad and can be up to 2m in diameter.,
How much water does gunnera need?
Ideally, gunnera needs loads of water to stay healthy as they grow in boggy conditions
Is gunnera invasive in the UK?
Yes, some species of gunnera are very invasive in the UK. Read more about the control of invasive gunnera here.
When do you uncover gunnera?
At the end of winter, early inspiring to allow new leaves to germinate.
When do you cut back gunnera?
Gunnera is a very invasive plant so it easily spreads and creates dense patches. You know it is time to cut back the gunnera plant when it begins to extend out of its planted zone to habitat and pastureland.