Forcing the Flowering Branches of Spring – Forsythia, Cherry, Kerria…

My friend Ilana the chicken lady has been busy tidying outdoors. “I have forsythia, Viburnum carlesii, flowering quince and Kerria japonica cuttings from spring cleanup,” she wrote. “ Will only the forsythia bloom? What about gooseberry and mock orange?

In theory, anything that blooms in spring on wood formed the previous year is a candidate for indoor forcing. In practice it all depends on:

1. Whether the flowers come out before the leaves. Plants that bloom on bare branches are usually easier to force.

2. How close to blooming the branch was when cut. Not surprisingly, the less time spent between cutting and natural flowering time, the better the odds of good performance.

3. Your willingness to fuss around with the cuttings after you bring them in. Easy forcers like forsythia, spirea, kerria, apple and flowering quince (Chenomeles spp) need only the standard cut flower treatment*

Fragrant viburnums and mock oranges (Philadelphus spp) on the other hand, are more like lilacs. All of these are mid spring bloomers that take much longer from bud swell to flower. Getting them to blossom indoors can be a challenge even when you cut them with first buds already open. The stems don’t take up water well, and because they leaf out before they bloom their first concern is with the greenery.

There are no guarantees, but these plants are more likely to force successfully if you submerge the newly-cut branches in tepid water for a couple of hours (bathtub!), then keep them someplace cool, moderately humid and out of the sun. If the bud scales dry out completely the flowers won’t open; if bud scales stay wet, they’ll rot. A controlled atmosphere storage area is very helpful, but not likely to be available unless you’re a florist.

As for the gooseberry; must say it’s an interesting idea; never would have thought to try forcing those thorny branches but now that you mention it, why not? The vaguely fuchsia-shaped flowers are unassuming from a distance, but they’re quite pretty close up. Just a branch or two displayed Japanese-style in a low vase might be very impressive – if you could get it to bloom inside. Gooseberries leaf out before they flower, so may well be in the “it’s harder” group. On the other hand, they do flower quite early, so… Ours are just starting to green up; I think I’ll go cut a branch or two and see how it does.

The Standard Cut Flower Treatment

is also the standard cut branch treatment:

1. Choose the squeaky clean vase or bucket or whatever and fill it 2/3 to 3/4 full with barely tepid water. If it’s a vase, add commercial flower preservative according to package directions.

2. Hold each stem upright next to the vessel to find the water mark, then remove all stems, leaves and flowers that would be under water.

3. Submerge the base of each stem in a shallow bowl of tepid water and cut it on the diagonal with a sharp pruner or flower shears. The entire cut should be under water. Transfer the cut stem to the vase/bucket.

4. Display or store out of direct sunlight and away from sources of  ethylene, a ripening gas given off by fruits, vegetables and other flowers.( Also, in small amounts, by gas stoves – another reason to be sure the kitchen is well ventilated.)

5. Change the water frequently. Repeat the stem-cutting routine every 4 or 5 days. Regularly remove dead blossoms and leaves; they too give off ethylene.