February 2018

Long-blooming perennials key to colorful gardens

Flower on — ‘Mainacht’ or May Night salvia blooms throughout the summer in a sunny garden. (Photo courtesy Bailey Nurseries )

Flower on — ‘Mainacht’ or May Night salvia blooms throughout the summer in a sunny garden. (Photo courtesy Bailey Nurseries )

We hear all the time about planning the perennial garden so that something is in bloom all the time. When Perennials Bloom by Tomasz Anisko (2008, Timber Press, $59.95) removes any guesswork. Anisko, a native of Poland, is the curator of plants at Longwood Gardens near Philadelphia.

With scientific research and record keeping, Anisko has chronicled the flowering time of 450 herbaceous perennials through several seasons. The result is a fairly precise range of when specific plants bloom and their peak times. The book breaks down the blooms by cultivars, too.

A few perennials bloom pretty much all summer. Several salvias (S. nemerosa) fit this category, including ‘Mainacht,’ or May Night, the 1997 Perennial Plant of the Year. This cultivar and a few others, bloomed from April or May into October or November. The key, he wrote, was to cut the salvias back after their first flush of flowers.  ‘Leuchstern,’ or Bright Star purple coneflower (Echinacea purpurea) had a slightly longer bloom time than ‘Magnus,’ but ‘White Swan,’ bloomed the longest, from May into October.

Anisko reminds us that the weather has a serious role in the plant flowering cycle. In his Longwood gardens, there was as much a five-week variance from mid-May to the end of June, when ‘Munsted’ began to bloom during the years of research.

Also, where a plant is located in the garden has an influence. Plants near a south-facing structure are more likely to bloom much earlier than the same plant in the middle of the landscape. That’s because the structure absorbs and retains heat, creating what’s called a microclimate.

He offers tips to help us extend the perennial garden blooms:

  • Select plants with long bloom cycles. “At Longwood, nearly half of all perennials flower, on average, for five weeks or fewer, but only one in 10 was in bloom for more than 14 weeks,” he wrote.
  • Make sure perennials are planted in their ideal location.
  • Provide adequate moisture to flowering perennials if Mother Nature runs dry.

This would be a beautiful and valuable reference for garden designers, landscape architects and avid gardeners. And, it would be a good companion to a similar book with an Indianapolis view, What Flowers When , by Jan Glimn-Lacy, $19.95 published by The Flower and the Leaf in 1995.

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