Irises Are May Flowers, Mostly

I wrote about irises, native and not, in the summer of 2020, but this time I would like to look at their succession through the bloom period, which starts in May and usually goes into June.
The month of May starts with native blue-eyed grass and Iris cristata, a US native, but not quite to this area. The blue-eyed grass, which is a failure in this yard as a bedding plant, adds a nice sparkle where it alights for about a month before it unobtrusively fades into the background. It is also extremely easy to remove unwanted seedlings as the root system is small.

Blue-eyed grass popped up in the gap between the driveway and the curb. A shadow of a developing flower shows through the backlit flower bud in the upper left-hand corner. Photographed on May 8, 2024.

I have had Iris cristata for many years now, and it never fails to delight me. They seem to be more sensitive to daylight than to temperature, so they are always showing buds a few days into May.

Iris cristata covered with flower buds, some of which have started to open in the upper right-hand corner of this photograph. Photographed on May 4, 2024.

They bloom slightly earlier if they get more sun. This spot gets plenty of water, which is key to this plant surviving in sunnier spots.

Iris cristata at the edge of the neighbor’s driveway, with bleeding hearts adding height and protection from the thorny roses a few feet back and off-camera. Photographed on May 2, 2024.

Iris cristata last less than two weeks, but as they fade, the more mainstream bearded irises are budding up. They bloom from mid-May into June in southeast Michigan. The bearded iris ‘Caprice’ smells like Concord grapes—very grapey.

The reddish purple iris ‘Caprice’ threading a path between the daylilies and larkspur. Shade is provided by a serviceberry. Photographed on May 22, 2024.

The iris ‘Batik’ is sitting in a bed on the west side of the house and gets sun much of the day. The amount of white in the flower is highly variable. It occasionally throws a very pretty sport, mostly white, which I move into a separate bed as they appear.

Iris ‘Batik,’ a highly variable purple bearded iris splashed with white. Photographed on May 18, 2024.

Not all cultivated irises are bearded irises, though. Overlapping the bearded iris bloom period is that of Iris pallida, which is lovely in bloom or not. My little patch started as a gift plant from a graduate student’s garden. The variegated leaves are very refreshing to the eye. The original plant has grown into a small patch edged with ornamental blue fescue, which rabbits mow and robins yank in late winter. The flowers are very nice, but the foliage is fabulous, and a beautiful contrast to the spiky blue fescue.

Iris pallida, a lavender iris with a long bottlebrush of a beard. Photographed on May 17, 2024.

As the month draws to a close, the Siberian irises and our native blue flag come into their own. The deep purple Siberian irises are in the floodplain, while the white Siberian irises are in the rain garden. Both spots get sun most of the day.

Siberian iris, Caesar’s Brother. Photographed on May 22, 2024.

I looked up the white Siberian irises; I remember being told that the white Siberian irises were ‘Butter and Eggs’ when I received them, but according to my search results, that’s the name of a bearded iris. I looked for images of white Siberian irises, and came up with flowers of varying shapes, which makes me relatively confident that these are actually ‘White Swirl.’ There is a ‘Butter and Sugar,’ but it is a bicolor: white standards and yellow falls. Standards are the more vertical petals, and the falls are the more horizontal spoon-shaped sepals.

Siberian iris, most likely ‘White Swirl.’ Photographed on May 26 2024.

Just south of these Siberian irises, the blue flag, which gets some dappled shade from an aged honey locust, also bloomed, and now has seedpods developing. My neighbor has blue flag in his rain garden in full sun, where it blooms more vigorously.

Blue flag in the dappled shade of a honey locust. Photographed on May 26, 2024.

I deadhead most of the irises, but allow the blue-eyed grass and blue flag to create pods. Blue-eyed grass set little pods that are slightly smaller than a peppercorn, but blue flag seed pods range from thumb to finger sized.

Seed pods of blue-eyed grass resting on a dwarf Japanese Solomon’s seal. Photographed on June 19, 2024.

I found a surprising number of seed pods on the blue flag. In retrospect, there were some flowers blooming daily, but the bloom period continued for over two weeks.

The blue flag seedpods still have the spent flowers dangling from their tips. The pods will spend the summer maturing. Photographed on June 19, 2024.

For the rest of the growing season, irises are nice foliage plants in this area—except the blue-eyed grass, which fades from notice.