Spirea in May: monthly care

Spiraea japonica thrives in full sun or partial shade, though flowering is most abundant in a sunny position. It tolerates a wide range of soils—loam, clay, or sandy—provided drainage is reasonable. Before planting, dig over the soil to a spade's depth and work in a bucketful of well-rotted compost or manure to improve structure and moisture retention, especially on light sandy ground. Plant container-grown spirea in March, April, May, September, or October. Avoid frosty or waterlogged conditions. Dig a hole roughly twice the width of the root ball and the same depth, so the top of the root ball sits level with the surrounding soil. Backfill with the excavated soil, firming gently with your heel as you go to eliminate air pockets. Space plants 96 cm apart if you're creating a low hedge or informal border; for a single specimen, allow at least 1 metre all round to accommodate the mature spread of 60–120 cm. Water thoroughly after planting—give each shrub a full watering can—to settle the roots. Apply a 5–7 cm layer of garden compost, bark chips, or leaf mould around the base, keeping the mulch a few centimetres clear of the stems to prevent rot. This mulch conserves moisture and suppresses weeds while the plant establishes. Newly planted spirea will need regular watering through the first growing season, especially during dry spells in late spring and summer, until the root system has spread into the surrounding soil.