Van Zyverden Kelvin Floodlight Dahlias outdoor plants are very easy to grow when grown from our tubers (bulbs) and we guarantee them to grow and bloom. If you have been to a state fair, you have probably seen a pavilion filled with these exotic, amazing garden plants. Collected by many gardeners, they make for sturdy varietal landscaping plants and are excellent in perennial borders. Each set comes with 5 bulbs.