You may be one of those gardeners that likes to see something in bloom somewhere in their garden from spring until fall frost. This goal provides landscaping focal points and is a worthwhile endeavor if you want to keep pollinators well feed during the growing season.
One can mix and match from an array of bulbs, annuals, perennials, shrubs and trees to achieve a continuous sequence of bloom. If you are adamant about having a continuous floral display and are still short of your goal, check out this publication from Cornell University: http://ccelivingstoncounty.org/resources/sequence-of-blooms.
Sometime after the release of this publication, Purple Loosestrife (Lythrum salicaria) was put on the invasive plant lists of many states. If you should find it for sale, please don’t purchase it.
I must admit that my own garden has blooming gaps. You can enjoy the “quiet” times between bursts of color or incorporate plants with colorful foliage. Such foliage can be just as eye catching and fill in those gaps.
Daffodils and Jonquils are the first to bloom in my garden. The burgundy leaves of Palace Purple Coral Bells provide a splash of color before the remaining spring players, Lilac, Dwarf Crested Iris and Peonies strut their stuff. My Viburnum (Summer Snowflake) blooms at the end of spring.
Before the summer floral display begins, leaves of Husker’s Red Penstemon and Red Switch Grass (Panicum virgatum Shenandoah) are large enough to provide focal points to some of the perennial beds. Soon Black-eyed Susan, Bee Balm, Mountain Mint, Common Milkweed, various Lilies, Yucca, Pink Diamond Hydrangea and Carolina Rose will be in bloom. These are followed closely by such notable fall players as Chrysanthemum, Joe Pye Weed, Closed Gentain, Goldenrod and Brilliant Sedum.
Winter can have its colorful focal points by incorporating Red or Yellow Twigged Dogwoods, Gold Coast, Blue Star or Grey Owl Junipers or Gold Mop Cypress, among others.
Plant annuals and perennials in groups of three to five or more for a better showing of flowers or foliage. A single large shrub can provide a large enough display by itself. In addition to the plants already mentioned, other plants with colorful foliage include Dusty Miller, numerous Coleus varieties, Silver Mound Artemesia, Canna Lilies (Tropicana and Red King Humbert have reddish foliage or Pretoria has yellow striped leaves), various Hosta, Lambs Ears, Tri-colored Beech, variegated Weigelia, Bloodgood Japanese Maple, Purpleleaf Sand Cherry, Royal Purple Smokebush or Diabolo Ninebark, to mention a few. Keeping track of your blooming gaps this year will help you fill them in next year.