How to Grow Dinosaur Gunnera

Start gunnera indoors from seed. Plant one of the disc-like seeds off the cone of a mature gunnera plant. Fill a pot with half peat and half potting soil and push the seed in at least 1 1/2 inches. Cover over with soil and compress lightly.

Saturate the growing medium with water until it runs freely from the drainage holes of the pot. Place the pot where temperatures are 65 to 70 F. The location may be dim to barely lit as the seed doesn't need light to germinate.

Keep the pot evenly moist until you see sprouting. Move the pot to slightly brighter conditions but avoid full sun. Transplant outdoors when the plant is at least 6 to 8 inches high and outdoor temperatures are warm, around 60 F or more.

Chose a location with partial sun for best growth. A fully sunny location is also appropriate. Dig in 5 inches of rich compost to provide nutrients and help conserve moisture. Gunnera can be planted near a water feature or pond and even where soils are boggy.

Plant the gunnera seedling at the same depth it was growing in its pot. Spread a 2- to 3-inch layer of mulch around the plant but leave 1/2 inch around the stem free of mulch to prevent rotting.

Spread slug bait around the plant once every two weeks to prevent slug damage on the huge ornamental leaves. Keep gunnera well watered and its soil moist to a depth of 12 inches. The plant can grow 4 feet in just a few months.

Cut the leaves back in the fall just before the onset of freezing temperatures. Remove them to the crown and lay them around the base of the plant as protection. Mulch around the root base of the gunnera with up to a foot of organic mulch, but pull it away from the plant in early spring.