Continuous Bloom of Perennials

The fashionable revival of perennials started a few years, so everyone had to have them. At a lecture I recently gave everyone grew them. Sophisticated gardeners all, they were competitive, snobbish and tried to outdo each other. They too had an unshared dirty little secret. It was this: When a bare spot appeared, they immediately filled it up with new plants, usually in the dark of night so nobody would know.

There exists this quest for continuous bloom in the perennial garden. It’s like the Holy Grail or Jason’s pursuit of the Golden Fleece or the surfer’s wait for that perfect wave. I have been pursuing perfect continuous flowering in my garden for a quarter century. And each year I am almost there.

But then reality happens. Bugs come. Animals chomp. Drought and neglect take a toll. (Vacations are the worst culprit.) Diseases kill. And each perrenial flowers only for about one to three weeks. (See the perennial flowering calendar at the end of this tale.) Some newer clones sputter along with new flower buds all season, but aren’t ever as full as that first glorious flush. And so those frustrating bare spots appear.

So let’s start with a basic design for continuous bloom. First, in early spring the bulbs appear, closely followed by a background of flowering shrubs and trees. May is always easy, many perennials flower. June is even easier and is the most glorious month, especially if some roses are in the background or over a trellis. July is pretty good, and even better if clematis is on another trellis. August is difficult. Everything has messy foliage and few if any flowers, unless you planned very carefully or planted annuals in June. Fall brings a palette of late perennials, big annuals, a second flush of roses followed by the colors of fall foliage.

But wait you say. This is a perennial garden. Ah but that is the dirty secret. If you want a really good season long sequence of bloom in your perennial bed, you have to augment it with other plants, especially annuals to fill in those inevitable bare spots. But don’t fret. It doesn’t mean you are a perennial failure. It’s just reality.

Why do we bother with a perennial garden? Because each week it’s different. Each year is a surprise. With the bulbs come perennial alyssum, iberis and violets. Peonies, iris and columbine follow. All through summer it’s a colorful minuet, flowers unfolding, leaping like a corps de ballet across the colorful stage we call our garden. It’s exciting. Who can resist?

There are many styles of gardens:
Carpet Beds are full of stuff. Often complex designs. Sometimes they’re French like in Versailles Palace. Sometimes lush and Victorian like in the parks and estates of England (which are the inspiration behind today’s fashion in perennial beds). Carpet beds require lots of flowers and lots of replacements. In England, they are often completely re-dug every few years…perennials and all.

Disneyland has taken this to a new exuberant, extravagant dimension. They change the beds completely 4 times a year or more if the flowers aren’t perfect.

Cottage Gardens are informal, sort of like casual, messy carpet beds. The patronizing word is "charming".

Great Gardens of Great Houses designed before 1930 have different perennial beds and garden styles for each season . They are like "rooms" often separated by walls or hedges. A spring garden. A rock garden. A June garden. A white garden. A rhododendron/azalea woodland garden. A summer garden, full of annuals and lilies. A fall garden with chrysanthemums and asters. And don’t forget a water garden with a weeping willow. Dumbarton Oaks in Washington D.C. and Longwood Gardens in Pennsylvania are typical and open to the public.

Monet’s Garden style is sort of an explosion of flowers in lush beds, in vibrant impressionist colors. Annuals, perennials, roses, vines and naturally the pond with water lilies. It’s a small garden but it has 6 gardeners plus greenhouses. They constantly replant and fill in the bare spots. When I was there they were planting 48 yellow flowers in an area about 2 square feet. Also dividing and replanting their entire iris bed. Oh would that I had just one of those French guys to help me.

Fashion being what it is, we still chase that myth of the perfect perennial border. Yet, in a small garden without an army of gardeners, it is a challenge. So what to do?

Make a plan. Carefully. Design it on paper. Then through the season, keep track of what performed well and what didn’t, so you can improve the plan the next year. The plan is half the fun. Try to cluster three or so plants of each variety together to make a better show. Repeat the clusters to make the eye move when looking at the garden. Consider different clones of the same plant, daylilies for instance, that bloom sequentially.

Read the catalogues with a jaundiced eye. Look for the words "vigorous" and make sure the plants are hardy in your region. One avid perennial gardener I know lives by the 1/3 rule. Each spring, 1/3 are dead, 1/3 he didn’t like and 1/3 remain to bloom again. (He spends a king’s ransom on plants each spring.)

Receive gift plants with grace for they are often the most vigorous. Otherwise people wouldn’t have so many to give away. Garden Club sales are a great source for best plants for your area. Of course, nothing is without a caveat. Make sure they are not too invasive like the mint family or barren strawberry.

Resign yourself to buying some "must haves" each year. Delphinium for instance. Mine never survive the winter, but oh, they are so glorious. And pure blue. There must be blue in my garden even though it’s so hard to find true blues.

Grow some plants that self seed. Annuals like cosmos and cleome for instance or biennials like campanula, digitalis and forget-me-nots.

Why bother? To delight in the colors and enjoy!

Credit: Mother’s Garden