Bridal wreath (Spirea x vanhouttei), sometimes also called Vanhoutte spirea, produces masses of small white flowers that cover the plant in spring. This drought-tolerant shrub doesn't need much maintenance. Bridal wreath, technically a hybrid, grows as a deciduous shrub in U.S. Department of Agriculture plant hardiness zones 3 to 8 and can be propagated from rooting cuttings.
Bridal wreath is generally easiest to propagate from softwood cuttings taken in late spring or early summer, although hardwood cuttings taken when the shrub is dormant can also produce roots. Each cutting should measure 4 to 6 inches long and should contain a stem tip. Use a sharp, clean knife to make each cut just below a node and from the upper portion of the bridal wreath plant to encourage better rooting. Store the cuttings in a plastic bag with damp peat moss or sand and keep them out of direct sunlight and areas with high temperatures if they cannot be placed in the rooting medium immediately. If the cuttings will not be inserted into a medium quickly, the cut end of each cutting will start to dry out. To account for this, make each cutting a few inches longer than you otherwise would and plan to cut the ends off immediately before inserting them.
Container and Medium
To avoid problems with disease, any container you use should be clean, free of debris and have plenty of holes for drainage and the growing medium must have excellent drainage and low or no fertility. Appropriate rooting mediums are commercially available at most garden centers or can be made by combining roughly equal parts peat moss and sand, perlite or vermiculite. A gentle but thorough watering before cuttings are placed makes it easier to hold the cuttings in place and minimizes settling later. If the cutting ends will be treated with rooting hormone, poking a hole into the medium for each cutting ahead of time using a pencil or other tool prevents rooting hormone from rubbing off.
Before inserting bridal wreath cuttings into the medium, trim off any dried-out ends and cut off all leaves emerging out of the bottom one-third to one-half of the cutting. Dipping the end of the cutting in a rooting hormone powder is not necessary but it will encourage more uniform root growth. Insert the cutting in the medium so its lowest remaining leaves are just above the medium's surface. Space multiple cuttings so no leaves from different cuttings are touching.
Encouraging Root Growth
Immediately after inserting the cuttings, mist or gently water the medium around the cuttings. To encourage rooting, the medium around the cuttings should stay constantly moist, but not soaking. Covering container with a glass or plastic lid or enclosing the container in a plastic or polyethylene maintains high relative humidity around the cuttings and minimizes the need for misting. Place the cuttings in a spot that receives bright, indirect sunlight. Once the cuttings develop several 1-inch-long roots they are ready to be transplanted into individual pots.