Perennial Bloom Calendar: Designing for Four Seasons of Flowers!

With a little planning, your garden can have blooms almost all year long. Unlike summer annuals that bloom consistently over many months, perennials generally have a window of time when their flower flushes appear. By following this guide, you can design a perennial garden that will provide four seasons of interest.

Visit a local gardening center in spring and you will find a myriad of perennial plants all in full flower. If you were to purchase a selection of these and plant them at home, chances are you would have lots of flowers for a few weeks or so, but then when summer rolled around your yard would have lost a lot of its bloom. That’s because for the most part, the showiest, most eye-catching plants in the nursery are for sale during their peak bloom time. If you shop a few times throughout the seasons, you’ll see different plants blooming at different times. With a little planning, you can design a garden with four seasons of flowers. This guide aims to help. We have selected a number of common perennial flowering plants and mapped out their general flowering times.

Even though each plant has its own common bloom time, there are many factors that affect when perennial flowers will appear

Seasonal issues: Every season is different. If, for instance, we have a very cold spring, this will probably push back the bloom times of many early season flowers. Alternatively, if we have a very warm spring, many plants will bloom early. A hot, dry summer with drought conditions may also cause a change in bloom times.

Age of Plant: More mature plants tend to put out more blooms over a longer period.

Culture: Following the recommendations for amount of sun, water, and fertilizer is very important to keep perennials blooming their best. If a sun-loving plant is put in too much shade, it will not perform well. If a plant does not get the amount of water or nutrients it needs it also will not perform.

Extending Bloom Times: Sometimes plants will put out another flush of flowers if they are sheared back after the first blooms fade. Plant tags will usually tell you if this is a good idea. Deadheading spent flowers can prolong blooming almost indefinitely. Perennials also may need to be thinned or divided every few years to keep them in top form.

Varietal Differences: Sometimes there are many species of the same plant that will have different qualities and bloom times. Check the tags or ask if you are unsure about when a particular plant is supposed to bloom.

Bloom Times for Perennials

Darkest-colored cells indicate main bloom time. Lighter-colored cells indicate start, finish, or sporadic bloom times.
*Indicates shade tolerance
**Indicates evergreen plant