• A large leaf from a giant plantWonderlust Industries/Photodisc/Getty Images
  
  Giant garden plants attract a lot of attention, make a great focal point and are just plain fun to grow. Giant plants give an exotic feel to gardens, according to Washington State University Clark County Extension. Many varieties of these plants reach a height of over 8 feet in a single growing season. The recipe for growing giant plants is to choose the right planting site, then make sure each plant receives adequate water and fertilizer.
  
  

Gunnera

• Gunneragiant gunnera plant image by Benjamin Jefferson from Fotolia.com
  
  Commonly called prickly or giant rhubarb, gunnera is one of the largest big-leaved plants available, according to Washington State University Clark County Extension. The average size of this giant plant is over 8 feet tall and 8 feet wide. Choose a sheltered location with moist soil that is high in organic matter. The ideal location would be in a bog or near a natural source of water such as a pond. Gunnera is a heavy feeder that requires fertilization monthly during its active growth period.
  
  

Valeriana Officinalis

• Valerian is smaller to many giant garden plants, reaching a height of 4 to 5 feet in bloom, according to Kentucky State University. Valerian will grow in full sun, but prefers to grow in partial shade. Amend the soil heavily before planting and side dress with phosphorus and compost yearly. In the home garden, valerian is valued for the highly fragrant pink or white flowers.
  
  

Rheum Palmatum

• Rhubarb plantrhubarbe 2 image by Nathalie P from Fotolia.com
  
  Like other members of the rhubarb family, ornamental rhubarb or wild rhubarb--the common names of Rheum palmatum--have toxic leaves, although the leaf stalks are edible, according to Cornell University Department of Animal Science. This plant reaches a height of 6 to 8 feet in the garden. The broad leaves and red leaf stalks give this plant a bold, architectural appearance. The pink to red flowers, which are prized as cut flowers, appear in mid-summer.
  
  

Giant Vegetables

• Giant pumpkinsGiant Pumpkin image by rikkidegraz from Fotolia.com
  
  Giant pumpkins are some of the most well-known giant vegetables, but they are not the only ones. Every year, young and old alike compete at both county and state fairs to see who grew the largest vegetables. Giant vegetables come from seed specially hybridized to create plants that produce larger than normal produce. Gardeners attempting to grow giant vegetables remove all but one or two fruits from the plant. This allows the plant to use all of its energy and resources to create a few larger fruits. Often, giant vegetables are started early indoors, then transplanted outdoors at the correct time so the fruit sets sooner and has a longer growing season.