Japanese spiraea

Japanese spiraea (Spiraea japonica 'Mertiyann' DAKOTA GOLDCHARM) requires regular watering on a weekly basis when its soil feels dry. During the hot summer months, the soil should be checked every couple of days and be watered if it is dry. During the winter, when the plant is dormant, it should be watered less often. Once every 1 to 2 weeks is sufficient. Make sure the soil never becomes overly dry or soggy as this could lead to root rot or other problems. 

Japanese spiraea prefers full sun (6-8 hours) or partial sun (4-6 hours) per day. This plant species prefers moist, well-drained soils and will not do as well in soggy soils. During the spring months, the Japanese spiraea should receive more sun than during the summer months. This is due to the hot summer temperatures in which the plant may suffer from sunburn or leaf damage if exposed to too much sunlight. Additionally, the plant may benefit from some afternoon shade.

Japanese spiraea requires moderate pruning to promote bushiness and keep its spreading habit in check. Prune from early spring to late summer, cutting back branches to just above the nearest healthy bud. Remove any dead, diseased, or damaged branches at any time of the year. If stems are thick and woody, make sure to cut back to a healthy bud to avoid stubs. For a more structured look, prune lightly every few years or so.