Giant Prickly Rhubarb or (Gunnera Manicata) isn’t even related to rhubarb in the least. And it does not cook up well with strawberries in windowsill pies.
The leaves of the Gunnera manicata Giant Prickly Rhubarb are very similar in shape and visual composition to that of the delicious true Rhubarb.This is where the similarity comes to a casual end for the colloquially as well as science savvy water gardener.
It would be great if we could eat them. Their size eventually grows so huge that you can literally hide in it. The Giant Prickly Rhubarb nick name of Gunnera Manicata reminds one of the fictional plants meant to feed the world in the storyline from 10,000 Leagues Under The Sea.That is how impressively huge these inedible plants grow to in a very short time.
The Manicata cultivar of the Gunnera species is one of the largest water garden shoreline plants. They grow best right at the edge of the water, or in bog gardens.
This does not exclude planting them successfully in rain gardens, or even less moist soil. But, in or near a water garden, or bog garden the plant genus and cultivar is pretty much maintenance free.
Many larger water gardens incorporate this cultivar and species as a matter of course.
Planting the Giant Prickly Rhubarb in direct sunlight, or slight shade both work well for the plant, the garden, and the gardener.
Planting in the shade can add color and texture often lost against the glare of the sun in some water gardens.
Planting in the sunlight provides a large amount of shade over the waters edge for water fowl, aquatic life, and other plants.
The leaves of Gunnera manicata or Giant Prickly Rhubarb as well as its distinct unfamiliar flower are what make most water gardeners, and bog gardeners have to incorporate this amazing looking plant.
The spiked stem stalks (called petiole) that support the leaves are thick hearty tubes that rise to support giant rough jagged edged heavily spined leaf heads who’s bright green covering can span up to 6 ft (2m) in diameter, and a leap year (4 yrs) in can grow up to 10 ft (3m) and spread across a 16 ft (5m) area. This is about the time that plant can no longer wait to be divided. The petiole are also home to many beneficial bacteria.
Some growers and care takers say that if the plant becomes injured wrapping the tuber in medicinal charcoal helps the plants healing process. So, far this has not been scientifically tested to be accurate. Prevention means keeping slugs and snails away; and cutting off dried leaves in the summer time.
The best time of year to divide Gunnera manicata is in the spring, or after the summer in fall. However, fall is more a time for the seeds of the plant to be harvested and cultivated for the next year.
The seed needs to be stored in a cold shelter container in a compost based from loam.
Over the winter Gunnera manicata Giant Prickly Rhubarb can handle temperatures dipping to 5º F (-15º C) if they are lightly sheltered from wind chill, and cold frost. For the most part Gunnera manicata are frost hearty and can do well down to down to 0º F (-17º C).
The seeds come from multiple exotic green five foot flower spikes that are themselves covered in spikes that are covered in orange tiny flowers. This flower seed producing spike is most easily described as being the shape of a bottle bush used in domestic dish washing. But the flower spike is much more easy on the eye than that description gives it credit for.
The Giant Prickly Rhubarb more effectively know as Gunnera Manicata and Mamutblatt (mammoth sheet) is from the Andes low lands of South America, but this nearly largest of the herbaceous plants is suited best for zones 5-10 of North America within the United States.