Grow Rosmarinus 'Blue Spire' for evergreen texture, fragrant foliage, and soft blue blooms that draw pollinators. You will get the best performance in full sun with fast-draining soil, where the plant forms a woody, upright shrub about 24-30 inches tall. In warm-winter climates it can be a dependable landscape herb, and in cooler areas it also does very well in containers that can be moved to shelter when hard freezes threaten.
Plant in a spot that stays on the dry side once established. Water regularly during the first growing season to help the roots settle in, then let the top few inches of soil dry slightly between deep waterings. Avoid soggy sites and heavy clay that stays wet, since good drainage is key to keeping the roots healthy. A light mulch can help reduce soil splash and moderate moisture, but keep mulch pulled back from the woody crown.
Prune after the main flush of bloom or as needed to maintain a compact shape. Make cuts into leafy growth rather than old, bare wood, and avoid heavy shearing late in the season so new growth has time to harden off. If you harvest stems for the kitchen, that regular clipping also helps encourage a fuller, bushier plant. The foliage is strongly aromatic and commonly used as a culinary herb.
Rosmarinus 'Blue Spire' pairs well with other sun-loving, drought-tolerant plants in rock gardens, Mediterranean-style beds, and warm-season borders. Good air circulation, full sun, and lean-to-average soils help it stay clean and vigorous with minimal fuss.