Spiraea japonica 'Rainbow Fizz' is a compact Japanese spirea with lively, changing foliage color and clusters of pink blooms in summer. You can use it as a small accent shrub, in mixed borders, or massed for a bright ribbon of color along a walk or foundation.
Plant it in well-drained soil and give it consistent moisture the first season so it can establish a strong root system. After that, it handles typical garden conditions well. For the strongest foliage color and the heaviest flowering, site it in full sun; it will also grow in part shade, though color and bloom can be reduced.
Mature size is about 36-48 inches tall and roughly 36-48 inches wide, forming a rounded mound. Space plants to allow air flow and room to fill in. Mulch helps even out soil moisture and keeps roots cooler in summer.
Prune in late winter or early spring before new growth begins, or lightly shear after flowering to tidy the plant and encourage fresh growth. Remove any dead or crossing stems as needed. This deciduous shrub is a reliable, easy-care choice when you want long-season color without fussy maintenance.