Flowering quince has been a favorite in the home landscape for generations, and old, tangled shrubs can often be seen at old homesteads, still blooming long after the original house is long gone. Also known as 'japonica,' flowering quince is a mid-size shrub with a rounded top, that will grow no larger than 6 feet at maturity. Although flowering quince will begin to bloom in late winter, it will be in full bloom by March. In mid-summer, flowering quince can be easily propagated by taking stem cuttings.
Use a sharp knife to cut a 4- to 10-inch stem tip from a healthy flowering quince bush. The cutting should be taken from a stem about the size of your little finger, and should have at least three sets of leaves. Take the cutting in the morning when the flower quince is still well-hydrated, and keep the cuttings cool until you're ready to plant them.
Fill a 4-inch planting container with a mixture of half sand and half peat moss. Spray the potting mix with a spray bottle until it's damp clear through, but not dripping.
Remove any leaves from the lower half of the stem, and dip the cut end in rooting hormone. Plant the stem cutting with the leaves above, and not touching, the soil. Use a pair of scissors to cut the leaves in half widthwise. Smaller leaves will take up less room in the pot, and will prevent moisture loss through evaporation. Several cuttings can be planted in the same container, as long as the leaves aren't touching.
Put the planting container in a plastic bag, and seal the plastic bag with a rubber band. It may be necessary to put stakes in the bag to keep the plastic from dropping down on the cuttings or the potting mixture.
Put the planting container where it will be in bright, indirect sunlight. Avoid putting the container in a windowsill, or anywhere that it will be in hot afternoon sun.
Check the potting mixture every week, and mist it if it's dry. Although the environment in the bag should be humid, too much moisture will cause the flowering quince cuttings to rot. If you notice beads of condensation on the inside of the bag, open the bag for a few hours, then seal it again.
Check for roots growing from the bottom of the pot in 3 to 4 weeks. Once the roots are about an inch long, remove the pot from the plastic bag and move each cutting into its own 6-inch planting container. At this point, begin gradually moving the flowering quince into more direct light.
Keep the soil moist through the winter. The following spring, the new flowering quince will be ready to be planted outdoors.