Mono bouquets in Chicago: lilac, tulips and the season for one variety
In the first two weeks of May, Lilacia Park in Lombard, a western suburb, blooms with more than 200 lilac varieties and 50 tulip varieties at once. Mono bouquets in Chicago follow the same idea: one variety, one wrap, nothing mixed in. A mono bouquet holds a single kind of flower, so choosing one starts with the month it grows in and how many days it holds up afterwards.
Lilac and tulips, the one-variety flowers of a Chicago May
Lilac is a short, sharp season. Lombard's bloom peaks in those first two weeks of May, and once it passes, the flower is gone until next spring. A lilac bouquet is one kind of flower in one shade of purple, which is why it reads as a spring gift rather than something ordered out of habit.
Tulips work differently. They are greenhouse-grown and cut from December through May, so a tulip bouquet is never only a May flower. It simply lines up with the city's own beds in spring, which is what makes tulip bunches feel seasonal even though the stems arrive from a greenhouse. The western suburbs' tulip rows are a Chicago sight, not a source for the bouquet itself.
Garfield Park and Lincoln Park's conservatories keep tulips, daffodils, orchids and delphiniums blooming under glass through spring, and daffodils come as their own mono bouquet, a single flower standing alone, the same way lilac does.
One thing shapes the vase, not the florist: a cut tulip keeps growing after the stem is cut, a centimetre or two a day, and it bends towards light. Filling the vase about a third with cold water and turning it once a day keeps the stems straighter for longer.

Peony season in the Midwest runs from late May into early June, a narrow window that makes peonies another gift tied tightly to its own few weeks. Once peonies finish, hydrangea and sunflowers carry the summer, and by late summer and into autumn dahlias and chrysanthemums take over, a calendar that follows the northern hemisphere's own turning seasons here in Chicago.
From May to October the Chicago Flower Market brings in stems from 31 Midwest farms, a sign that the city has its own local cutting season through the warmer months, separate from any single florist's supply.
Hydrangea drinks more than most cut flowers, and a head that has gone limp can be brought back by resting it, flower and all, in cool water for an hour or two. Through a Chicago summer the heat asks more of any bouquet; a short note on keeping flowers through a Chicago summer covers that.
Which single flower lasts through a Chicago winter
Once local cutting ends for the year, mono bouquets in Chicago turn to greenhouse flowers such as chrysanthemum, lily and lisianthus, all grown under glass and available whatever the month.
Chrysanthemum, carnation, alstroemeria and cut orchid are the longest-lasting of the group, holding for two to three weeks in water. That staying power makes any of them a sound winter desk gift, something that still looks fresh weeks after it arrives.
Lily is the one exception worth knowing before sending it to a home with a cat. Every part of the plant is toxic to cats, and so is the water left in its vase. A home with a cat is better served by a different single flower, lisianthus among them.
Each bouquet is made to order, and delivery timing for Chicago is on the delivery page.

A gift in spring points towards lilac or tulips, in June towards peonies, and through the colder months towards lisianthus or hydrangea once it is back in season. Whichever month it is, start with the flower that is in season or known to last well.