Trying to propagate this plant. Took softwood cuttings in June, planted in soil less mix and kept in a portable greenhouse in the shade. They,looked good for about a week then started to turn brown. Some seemed to have roots after 2 weeks but none survived to start growing. What am I doing wrong. Should the cuttings remain green throughout the process?
Thanks for contacting Toronto Master Gardeners. It is possible your cuttings weren’t ready for rooting. It is a challenge to know when a shrub is in the softwood stage. Softwood lies between the new, green growth at the end of a shoot and the stiff, woody growth near the base of the stem. You can assess whether the shoot has reached the softwood stage by bending it. If it snaps, the shoot is ready to be taken as a cutting. If it bends but doesn’t snap, it’s too young and if it’s rigid it is no longer softwood. Most softwood cuttings are ready between mid and late summer. Perhaps the cuttings you took in June were too green. Green cuttings will rot before they can root. For more information on propagating spirea shrubs with soft wood cuttings please review the following sites:
https://homeguides.sfgate.com/spirea-propagation-75615.html