This site is meant to illustrate the results of a trial at Cornell University, in Ithaca, NY (Hardiness zone 5) in which spring blooming bulbs were combined with established perennials to determine whether the two would be compatible planting companions.The trials were planted fall of 2004 at the Bluegrass Lane Research Facility; flowering and timing data were collected in 2005-2007.
Why are Bulb and Perennial combinations useful?:
Extending the bloom season. Since bulbs are the earliest major component in the garden, their use is of obvious importance in lengthening the season of the garden.
Hiding/covering senescing bulb foliage. After a spring bulb flowers, the leaves senesce (lose their green color), a process that lasts several weeks. While important for bulb filling and, ultimately, long-term perennializing of the bulb, the yellowing leaves are unsightly. Thus, the functional covering of bulb leaves can be an important facet of a good combination.
Contrasting or complementary leaf texture. Leaf texture is an important design element, and due consideration should be given to it.
Color. Most spring bulbs flower before the majority of herbaceous perennials. Thus, color can be used in a sequence from bulb to perennial. The result is a longer season of bloom within the same garden space. One may also use color from one plant to complement or contrast the colors of another. This is called “color echoing” and is an important way to tie plants together in the overall design. Color echoes may occur between leaves and flowers (Tulip ‘Queen of Night’ and Sedum ‘Matrona’) or between flowers (Narcissus 'Ice Follies' and Pulsatilla).