Giant Rhubarb foliage
Giant Rhubarb foliage
(Photo courtesy of NetPS Plant Finder)
Height: 10 feet
Spread: 10 feet
Hardiness Zone: 7
Other Names: Brazilian Gunnera
A gorgeous specimen plant for a large garden area; massive leaves on stalks rise up to 10 feet and unfurl up to 6 feet wide; it loves moist to wet enviroments so it is great alongside a pond; can be invasive in moist warmer climates;
Giant Rhubarb’s attractive enormous serrated lobed palmate leaves remain green in color throughout the year. Neither the flowers nor the fruit are ornamentally significant.
Giant Rhubarb is an herbaceous evergreen perennial with an upright spreading habit of growth. Its wonderfully bold, coarse texture can be very effective in a balanced garden composition.
This plant will require occasional maintenance and upkeep, and is best cleaned up in early spring before it resumes active growth for the season. Gardeners should be aware of the following characteristic(s) that may warrant special consideration;
Giant Rhubarb is recommended for the following landscape applications;
- Mass Planting
- General Garden Use
Planting & Growing
Giant Rhubarb will grow to be about 10 feet tall at maturity, with a spread of 10 feet. It has a low canopy with a typical clearance of 2 feet from the ground. It grows at a medium rate, and under ideal conditions can be expected to live for approximately 8 years.
This plant does best in full sun to partial shade. It prefers to grow in moist to wet soil, and will even tolerate some standing water. It is not particular as to soil pH, but grows best in rich soils. It is highly tolerant of urban pollution and will even thrive in inner city environments. Consider applying a thick mulch around the root zone in winter to protect it in exposed locations or colder microclimates. This species is not originally from North America.
Learn About Gunnera Care: Tips For Growing Gunnera Plants
If you’re looking to make a statement in your yard and have some low-lying ground to plant, the Gunnera is a great choice for visual impact. Let’s learn more about how to grow Gunnera plants.
Gunnera Plant Information
Sometimes called Dinosaur Food (Gunnera manicata), the Gunnera’s deeply-lobed leaves can get up to 4 feet across and the plant can stand up to 8 feet tall. Gunnera tinctoria, also known as prickly rhubarb, is similar and just as big. Both of these prehistoric-looking greenery plants will fill in large empty spaces in the corners and edges of your yard, and will thrive in boggy ground where other plants’ roots might drown.
Growing and Caring for Gunnera
The most difficult part about caring for Gunnera is its moisture requirements. If you have a piece of ground that is constantly saturated from deck run-off or some low ground at the bottom of a hill, you’ve found the ideal place for growing Gunnera plants. Gunnera loves moist and boggy ground and must be kept well-watered at all times. Set a sprinkler next to the plant and let it go for an hour or so, as the leaves love moisture as much as the roots do.
Choose your planting spot in low ground that gets full sunlight for at least most of the day. Dig in lots of compost and other organic material when preparing the ground for planting. Give the plant a heavy feeding when you first plant it to give it a good start.
It takes a lot of energy to create this much growth, and this makes Gunnera a heavy feeder. In addition to the fertilizer you dig in with the first planting, feed them twice more during the season with a good, all purpose fertilizer. Side dress the plants and water the fertilizer into the soil next to the crown.
Many perennial plants can be propagated by dividing, but the Gunnera is so large that this method is hard to use. The best way to increase your Gunnera plot is by cutting out a portion of the crown much like you’d remove a wedge of pie. Do this in April or May before the main growth has begun. Plant this new juvenile plant at least 10 feet away to give both plants room to grow.
Gunnera may be tough, but it can be damaged by winter frost. Cut the leaves down around November and pile them on top of the center crown left in the ground. This will insulate the more tender parts of the plant from the cold. Remove the dead leaves early in the spring to allow new growth to spring up.