Rosmarinus officinalis "Arp'"

'Arp' is the rosemary to grow where ordinary rosemary freezes out, the cold-hardiest of the common culinary rosemaries and a genuine boon to gardeners north of the herb's usual range. Selected in 1972 from a plant growing at Arp, in east Texas, by the noted herb grower Madalene Hill, this selection carries the same needle-like evergreen foliage, aromatic and useful in the kitchen, on a robust, bushy, upright frame, with the bonus of a distinct lemon note in the scent and a soft gray-green cast to the leaves.

Hardiness is the whole point. Where most rosemary gives out around twenty degrees Fahrenheit, 'Arp' comes reliably through USDA zone 7 and, in a sheltered spot with sharp drainage, into zone 6, holding evergreen through winters that turn ordinary rosemary to brown sticks. Soft blue flowers open along the stems from winter into spring, drawing bees, and the whole plant is tough, drought-tolerant, and famously low-maintenance.

For all the extra hardiness, 'Arp' is fully a culinary and medicinal rosemary. The fragrant leaves season roasts, breads, and oils exactly as the species does, and share the long European tradition of rosemary as a digestive and reviving herb, along with the rosmarinic and carnosic acids behind the modern interest in the plant. The aromatic foliage is left alone by deer.

Give 'Arp' the hot, bright, sharply drained site all rosemary wants: a herb garden, a sunny border, a gravel or Mediterranean bed, or a large container by the kitchen door. Full sun, lean, well-drained, neutral to slightly alkaline soil, and good air movement are the whole secret, and in the coldest gardens a sheltered spot near a warm wall or a sand mulch buys a few extra degrees. Drought-tolerant once established, and the hardiest rosemary for the cook who wants the herb to survive the winter outdoors.