Gardening: Old-fashioned dahlia a stunner

Nancy Szerlag
Special to The Detroit News
‘Bishop of Llandaff’ is an heirloom bulb.


When perusing the Old House Gardens Heirloom Bulbs catalog (, I came upon an old friend and favorite dahlia, ‘Bishop of Llandaff.’ It sends up brilliant scarlet single to semi-double flowers on long stems from a good-sized cluster of eggplant to almost black-colored foliage that is so popular these days.  To my eye, the dark-colored leaves by themselves are dramatic accents I value in the garden. 

   I first set eyes on the ‘Bishop’ many years ago in the iconic garden of Daniel J. Hinkley – the famed Heronswood. Hinckley, a cutting-edge garden designer, plantsman and purveyor of rare perennials and shrubs, had many surprises for our large band of professional garden communicators – the Garden Writers Association, which descended on his gardens as part of our annual symposium. At that time the highly colorful annual – technically tender perennial bulbs –  were out of fashion with top garden designers, so it was a great surprise to see the showy 'Bishop' popping out of an artfully arranged collection of foliage plants, making it an “ah-ha” display.  

Like a lot of my favorite plants, 'Bishop' has a rich history. Bred in Wales, it won the English Royal Horticulture Award of Merit in 1928.  

Today a seed strain relative produced from this plant labeled ‘Bishop's Children’ sports the same dramatic dark foliage and can be found in a mix of flower colors, including yellows and oranges.

Native to South America, dahlias are prolific bloomers that normally begin to flower in mid-summer and if kept dead-headed, will continue to bloom until the first frost. True heat lovers, they are cold sensitive, so greenhouse grown plants should not be planted out in the garden until all threat of frost has passed.

The popularity of cutting gardens and pollinator attractors has really thrust these old-fashioned favorites into the spotlight. Dahlia blossoms range in size from a couple of inches to a foot or more in width – these monsters are known as dinner plate varieties.  They come in all colors except blue and range in height from 6 inches to 6 feet or more. Tall varieties will need staking.   

The secret to keeping them flowering is dead-heading by carefully cutting the stems of aging blooms off at the base where they emerge from a branch, stimulating the plant to produce more blossoms.

Appearances: Join me at English Gardens Plymouth Nursery for my program "Kitchen Gardening: How to Grow Sprouts and Microgreens" at 12 noon Saturday  and 1 p.m. Sunday. Programs are free. For more information go to  or call (734) 453-5500. 

Nancy Szerlag is a master gardener and Metro Detroit freelance writer. Her column appears Fridays in Homestyle. To ask her a question go to and click on Ask Nancy. You can also read her previous columns at