Winter-tender shrubs, such as abelia, tamarisk, and butterfly bush, kill back to the ground annually in some areas.  All three are semi-hardy in temperate climates but need shelter near a wall to avoid permanent damage from cold northwest winds.

Abelia
The grandiflora hybrid is the hardiest abelia and can be grown as far north as New York City.  Used as an informal hedge, abelia's graceful beauty is retained with only selective thinning.

Prune abelias in April.  They develop flowers on new growth.  Cut off all growth showing damage that occurred during the winter.  Look for crowded stems and cut out a third of them almost to the ground.  On mature shrubs, cut out some of the oldest wood to stimulate young wood that flowers well.

If abelia is killed to the ground by a severe winter, cut off all dead branches to near the soil surface.  New shoots will grow when the weather warms.  In the coldest areas, where killing back is even more severe, the entire shrub should be cut to within several inches of the ground late in the fall and mulched well as soon as ground has a frozen crust.

Buddleia
The alternifolia species or fountain butterfly bush usually doesn't die to the ground like other buddleia.  To encourage new growth for next season's bloom, remove some of the oldest canes immediately after flowers have faded in the spring.  To keep large plants vigorous, remove up to a third of the oldest canes each year.  Leave four- or five-inch stubs with at least two buds.

The Buddleia davidi (summer lilac or orange-eye butterfly bush) is another popular butterfly bush.  This one does tend to be killed to the ground by most winters, so cut bushes back near to the soil level and allow two buds on each stub.  As soon as new shoots have grown a couple of feet, thin out the youngest ones, saving the most vigorous.  Then pinch the tips off those shoots remaining.  In very cold areas, mound up soil eight or more inches around the base to protect buds near the ground level.  Remove the mounds in spring and cut back tops several inches when the danger of frost has passed.

Tamarisk
The ramosissima species develops its flowers on a current season's growth, so prune plants severely to a few inches in early spring, while the plant is dormant.  Head back to keep the shrub within the scale of your landscape design and to avoid a bare, open base.  Clip flowers off immediately after they bloom.