For more than a decade, I have organized the bloom date project. The project collects data on the date on which a cultivar first blooms. The project provides new more precise data about when particular cultivars bloom. This helps the home garden to plan. Details of the project can be found at
This Spring was the first time that I have collected bloom data from the Oshawa Garden. Each day I went to the garden and marked which cultivars had bloomed for the first time. Blooming began on May 21st with Early Windflower and Nosegay. The latter is one of my five favourite peonies and I would recommend it to everyone. Early Windflower is a tall and stately plant with a very long period of bloom. Only about fifteen cultivars bloom in May but these are very beautiful. These include the tenufolia hybrids such as Laddie, Early Scout and Smoothii. There are also important and lovely Saunders hybrids such as Audrey, Rose Crystal and Roselette. Gardeners should grow some of these early blooming peonies to extend their blooming season.
In recent years, Oshawa has increased the number of tree peonies and this will continue for the next few years. There are about forty tree peonies and these bloom in the last week of May and the first week in June. A visit in the first week in June will provide many gorgeous tree and herbaceous peonies. I did not collect data on the individual tree peonies.
In the first week in June, more of the herbaceous hybrid peonies bloom. This includes Red Charm, Jewel, Nathalie, Chocolate Soldier and Illini Belle. There are many rarer peonies that may interest you. Some will be difficult to find. By coming in this week one can see both tree peonies and exquisite herbaceous ones. At the end of the week, none of the lactifloras have bloomed. All of the blooms have been hybrids or tree peonies. This implies that doubles have been rare and that no Japanese have bloomed.
Almost one-half of the cultivars open in the second week in June. This is a grand week. The hybrids are still blooming and the lactifloras are rushing into blossom. There are too many lovely cultivars to list here.
Almost one-third of the plants do not bloom until the third week in June. The hybrids with their vibrant colours are gone but the lactifloras are booming. This is the time for many peonies with a Japanese flower form.
My last garden trip was on June 22. I could not find any peonies that had not opened. The blooms were everywhere and some blooms would last until at least June 27th. Among the last to open were Elsa Sass, Ann Cousins and Myra MacRae.
I collected bloom dates on about 250 cultivars. A few plants did not bloom this year and a few were missed as I walked the gardens. By visiting the garden many times, I appreciate many plants that I had not noticed in earlier years.
Submitted by Michael Denny