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Peony Bloom Countdown


2015 Peony Season underway

Current Status as of May 29, 2015: Beautiful buds are opening quickly now.  Be sure to stop by this weekend and next week as many of the peonies will be in full bloom by then.  Here are some more photos from this morning, May 29, 2015.

Status as of May 28, 2015: Many buds are beginning to open, with our estimate of about 3-5% of the peonies in bloom. This weekend the real show should begin. As always, check back here every day for regular bloom updates. A couple of representative pictures from May 28, 2015:


Status as of May 26, 2015: The Nichols Arboretum Peony Garden is proving again how plants bloom on their own schedule. Lots of buds showing lots of color today but still not much noticeable flowering. We're now guessing---with temperatures forecast to be in the 80s over the next few days---that this weekend or early next the plants will begin to bloom in earnest. Stay tuned. (Pictured below: Buds with color: Yes. Blooms: not many yet but soon.)




Status as of May 24, 2015: Memorial Day weekend is a good time to set your peony clock but this season, thanks to cooler weather, the peonies are just later than we'd like. There are two herbaceous peony plants blooming. And there are many tree peonies blooming, too. Definitely worth your time this evening or on Memorial Day to stop by the Nichols Arboretum Peony Garden and breathe in that sense of anticipation. Many herbaceous peonies are showing color in their buds. Warmer temps at last will mean this week is a good bet for bloom. Stay tuned as we update this peony web page as often as we can to bring you news about the peony garden! Some pictures of tree peonies and an azalea blooming on Laurel Ridge below.


Status as of May 22, 2015: The cooler temperatures have slowed the blooming progress this week, but as the temperatures rise, a few herbaceous peonies have started flowering.  The warm weather coming next week will cause more peonies to bloom, and the garden will start showing its colors very soon!

Status as of May 20, 2015: Due to the cooler weather, many herbaceous peonies have yet to flower. The cool weather is preserving those flowers that have already bloomed.  Many tree peonies have already bloomed, and weather permitting, herbaceous peonies should flower within the next 1-2 weeks. 

Status as of May 18, 2015: Many tree peonies are beginning to bloom. As part of our Peony Garden Rejuvenation Plan we’ve been installing tree peonies and other plants in and around the Peony Garden proper. Tree peonies bloom a few weeks before the herbaceous peonies. Tree peonies are called the King of Flowers and are exalted in the arts as well as used in medicines. Our Peony Garden Rejuvenation Plan of 2012 includes beds devoted to tree and herbaceous peonies from China, Japan, and Korea. 

 Also from May 18: more tree peony photographs, plus a picture of some herbaceous peony buds for a look at the flowering progress of the main peony garden:


Status as of May 15, 2015: Nearly all the peonies are lush and full. Curator David Michener guesstimates another two weeks before substantial bloom. As always with gardens and plants that timing may change. Warm weather and rain predicted this weekend followed by cooler temps could create a "hurry up and wait" scenario in which the plants are pushed along and then slowed down by chillier weather.

Status as of May 13, 2015: Tree peony 'Hephestos' is blooming in the peony garden. Tree peonies usually bloom 1-2 weeks before herbaceous peonies flower.  The cooler weather will keep the blooms fresh for several days.

Status as of May 8, 2015: Many of the plants are showing flower buds. A good percentage of plants are now 12-18 inches tall. Another warm day today plus rain predicted for the weekend will push the plnst even further along. Then a cool down in store for next week. The push-pull and, ultimately, the unpredictability of plants, nature, and weather.

Status as of May 6, 2015: The peonies are getting taller. Recent rain and more to come plus much warmer temps mean accelerated growth for the plants. What does this mean? The garden is likely on schedule unless we get cold weather later in May---not unknown in Michigan. Stay tuned for more frequent updates as May unfolds.

Status as of April 28, 2015: The peony plants are beginning to sprout. After the long Michigan winter it almost seemed like spring would never happen, but it's here at last. Warm days ahead and rain next week bode well for continued vigorous growth.

Status on April 6, 2015: Spring has officially arrived and some of the peonies have begun to emerge. A welcome sight!

Status on March 19, 2015:The snow has melted from the main beds, but the peonies have not begun to emerge. More cold weather is expected through the end of the month; the peonies will begin to emerge once the ground thaws.

Status on February 13, 2015: It's the depth of winter's cold here in Ann Arbor, so the peonies are dormant. That's good - peony roots require winter chilling for the plants to grow well the next year (and one reason you don't find peony gardens in warm-winter climates). Once winter ends and the peonies begin to emerge, we'll post our pictures and best-estimates of when the garden will begin to come into bloom, as well as peak bloom. 

Peony Garden on Friday the 13th Feb.,  2015 (can you find the human-sized snow man?)

What is peak bloom? Peak bloom represents an ideal time to visit the garden and see many different peonies in bloom. Bloom season estimate in any given year is a staff "best guess" and will be updated as spring progresses. It is difficult to predict exactly when the peonies will bloom too far in advance. They choose their own schedule!




The Peony Garden peak bloom time usually begins in late May to early June. This is when a majority of the herbaceous peonies burst into an intense display that usually lasts about two weeks.

  • Peak bloom may arrive more than 10 days early if unusually warm weather "pushes" the garden, or it can be delayed if we have an extra week or more of cool days and nights. The duration of peak bloom depends on the weather, too. Hot dry winds take the garden down days too early for us; calm cool days can extend the peak season by nearly a week.
  • The Peony Garden is always into its post-bloom summer growing season by the Summer Solstice.


An urban myth says there is a peak day when all are in bloom. Not so - there is a peak season. Since each peony blooms on its individual schedule based on weather and genetic programming, there has never been a "peak day" when all are in bloom. Nor will that ever happen. So enjoy them in bloom and revel that Nature runs on its own calendar.