Salvia rosmarinus 'Arp'
herbArp Rosemary (Salvia rosmarinus 'Arp') is the benchmark cold-hardy rosemary, discovered in 1972 near the town of Arp in east Texas and prized for surviving winter temperatures down to about -10F. That hardiness extends dependable rosemary into zone 6, well beyond the mild-winter range of most varieties. It is an upright, open, vigorous shrub reaching 3 to 5 ft, with slightly longer, lighter gray-green, spruce-scented needles and pale blue flowers in spring. The flavor is full and resinous, excellent for roasts, breads, and grilling, and like all rosemary it is evergreen, drought-tough, and beloved by bees.
Sun
full sun
Water
Every 10 days
Harvest
~90 days
Difficulty
medium
Lifecycle
perennial
Comes back every year
Spacing
24-36 in. apart
Planting Depth
Crown at soil line
Soil pH
6.0-7.5
Soil Type
Sandy, sharply draining
Hardiness Zones
Zones 6 – 10
When to Fertilize
None to light in spring
Fertilizer
None; compost lightly if soil is poor
Plant Arp Rosemary in full sun and sandy, sharply drained soil - wet feet, not cold alone, is what kills rosemary in winter. Space plants 24 to 36 in. apart. Water to establish, then only during drought; it thrives on neglect and lean soil. In zone 6 and colder margins, site it in a sheltered spot against a south wall or near heat-holding rocks, mulch the base, and protect from drying winter wind; where winters are too harsh, grow it in a pot and move it to a cool bright room. Prune lightly after flowering to shape, never cutting hard into old bare wood. Do not overfertilize.
Direct sow
Apr 15
Projected first harvest
Jul 14
Good neighbors that attract beneficial insects or deter pests
Proactive ways to stop trouble before it starts — tap a name with an arrow for its full guide
Give full sun and excellent airflow, avoid overhead watering, and do not crowd plants - mildew follows damp, stagnant conditions, especially indoors in winter
A frequent problem on indoor-wintered rosemary - raise humidity, rinse the foliage, and inspect regularly
The biggest killer - plant in sharply drained soil and never overwater; soggy roots in cool weather are fatal
Harvest rosemary year-round by snipping 4 to 6 in. sprig tips, which also shapes the plant; cut lightly and never strip more than a third at once. Use sprigs fresh or strip the needles for chopping into roasts, potatoes, breads, and marinades. Rosemary dries and stores extremely well - hang bundles in a warm airy place and the dried needles keep their punch for months. Woody stems make fragrant skewers for grilling.
Arp Rosemary provides the same robust, resinous, pine-citrus flavor as common rosemary, used to season roasted meats, potatoes, breads, focaccia, and Mediterranean dishes, and to infuse oils and vinegars. The aromatic oils are rich in antioxidants. Its spring flowers are also an early nectar source for bees, and the evergreen shrub adds year-round fragrance and structure to the herb garden.
For educational and informational purposes only — HomeSown is not medical, health, or other professional advice. Always positively identify any plant before handling or eating it; some plants, and some parts of otherwise-edible plants, are toxic. Consult a qualified professional before consuming or otherwise using any plant, especially if you are pregnant, nursing, taking medication, or have a health condition.