Red maple flowers are among the first tree flowers to emerge in Maine each spring. Credit: Courtesy of Karen O. Zimmermann

Snowdrops, daffodils and crocuses are shouting, “Spring is here,” but the trees overhead just whisper. With late April snow squalls and temperatures dipping below freezing, it may be hard to believe those loud flowers, but take a closer look at all the bare twigs, black against the sky. They are expanding and growing — it is just subtle. This is the time to get out there, clip a few branches and watch the show unfold.

The practice of collecting branches from spring-flowering shrubs and trees, then coaxing them to bloom early indoors, is known as “forcing spring.” In Maine, a wide variety of plants can be clipped for this activity.

Right now, red maples, Acer rubrum, are swollen with spring anticipation; many buds have already opened into scarlet-petaled flowers fringed with yellow anthers. Red maples have male and female flowers and a complex reproduction cycle, but simply watching the flowers develop is enthralling. If you want the whole story, hunt down “The Sex Life of the Red Maple” by Richard Primack. It is a perfect read as you wait for the blooms to develop.

[image id=”2969535″ size=”full” pos=”center” /]

Both of our aspen trees lend themselves to early catkin (flower) production. The droopy silver, caterpillar-like catkins of the trembling aspen, Populus tremuloides, are spectacular. They hang like inflated tinsel off branches when leaves are just a gleam in the eye.

The reason aspen, and many other trees, flower early (and even earlier if we force them) is because they are wind-pollinated. This is also why their flowers are elegant, modest and refined. They do not need to advertise to pollinators. What they do need to do is get their pollen dispersed, and once the trees have a full head of leaves blocking air traffic, that will be difficult. With no leaves, the pollen can drift unhindered from the catkin to a neighboring tree.

[image id=”2969537″ size=”full” pos=”center” /]

Oak and ash trees have flowers worth watching, too. I have photographed and drawn them as they bloom in the field, but not forced them. This year I have clipped twigs from both and hope to see them transform day by day.

Forcing spring is an annual ritual at my house. Scarlet maple with silver gray poplar catkins is a favorite combination of mine. But pretty much any winter twig can be coaxed into an early bloom with warmth and water. I have brought in twigs from bayberry, alder and most of the maples. Forcing the early unfurling of horse chestnut leaves with their sticky buds and the emergence of pale pink flowers on a cherry branch offer a slightly guilty pleasure.

While I find the details and delicacy of the tree flowers the most rewarding, even just a spray of vivid green aspen leaves brighten a room. Flowering shrubs are fair game, too. Quince, forsythia and honeysuckle all flower quickly.

[image id=”2969538″ size=”full” pos=”center” /]

How to ‘force spring’ indoors

Get some clippers and head into your yard. Cleanly snip twigs at a slight angle. I use sharp Japanese clippers, which have just the right strength for a branch about quarter inch in diameter or a bit larger. For larger twigs, I use secateurs or bypass pruners (which do not clip as neatly but are stronger).

Place your branches in a jar or vase with room temperature water and watch the show. Maybe write in a journal how long it takes for flowers to develop, and which ones are faster. Some respond more quickly to the nudging than others. They are sometimes slow to start, and I like to keep a magnifying glass nearby so I can check for even small progress, then to admire the details of the flowers themselves.

[image id=”2969539″ size=”full” pos=”center” /]

If you need them for a special occasion and forget to plan ahead, putting them in the shower with a warm rain can hasten their progress. The later in the season they are clipped, the more quickly they will bloom.

While forcing twigs to flower or leaf out is really easy, there is the possibility that a twig will refuse. I had one failure with lilac, which I attempted because my daughter loves the scent. The branches sat for weeks, unchanging. The water got dirty. The buds were as tightly closed as the day I brought them in. Then they fell off. If you get them to bloom let me know what you did.

It is not too late to go out and clip a few branches to bring an early spring inside your home. When you look out the window and see the next April snow showers come laughing down, ask the trees if spring is coming. Your tree flowers will tell you, “yes.”

Karen O. Zimmermann lives and explores on Mount Desert Island, finding delight in the changing seasons and the world of nature both underfoot and overhead. A Maine Master Naturalist, she is the author of the BDN blog Maine Morsels.