Arp Rosemary

The most cold-hardy rosemary cultivar available, surviving winters down to minus 10 degrees Fahrenheit with proper drainage. Discovered in Arp, Texas, this variety has grey-green leaves with good culinary flavor and light blue flowers. Essential for gardeners in zones 6 and 7 who want to grow rosemary as a perennial outdoors.

Rosemary is best propagated from semi-ripe stem cuttings rather than seed, as seeds are slow, unreliable, and variable. Take 10cm cuttings from current season's growth in late spring to midsummer. Strip lower leaves and dip in rooting hormone. Insert into a mix of perlite and peat, keeping warm (20°C) and moist but not wet. Rooting takes 4-8 weeks. Alternatively, layer low branches by pegging to moist soil—roots form in 8-12 weeks. Seed germination takes 2-4 weeks at 20-25°C with very low success rates.

The Season Plate

Your Arp Rosemary Year

Composed for Zone 7 · typical seasons · frost passes Apr 2, returns Nov 1

Sow Arp Rosemary Mar – May, pick Jan – Dec. Set your climate below and every date on this plate re-times itself.

Sowing window

Mar – May

re-timed to your frost dates

Plant out

after Apr 2

once frost risk has passed

First picking

around Jun 13

≈ 90 days from sowing · 1 to per plant

Composed for —ColdTemperateMildWarmUse my locationUsed once to set your season · only the zone is kept

Week-by-week Arp Rosemary reminders watering, feeding and pruning, timed to your dates

In the app

Frost alerts for your garden a warning before a cold night costs you the crop

In the app

Succession sowing dates so the picking never gaps mid-season

In the app

Keep my dates — free for 7 daysWe nudge you as each window opens · cancel anytime

Arp rosemary is the most cold-hardy rosemary cultivar available, reliably surviving winters to -23°C (-10°F) with proper drainage—a game-changer for gardeners in zones 6-7 who want perennial rosemary. Discovered in the town of Arp, Texas, this variety combines excellent cold tolerance with good culinary flavor. Plant in spring in a south-facing, wind-protected location with well-drained soil.

Excellent drainage is the single most important factor for winter survival—more cold-climate rosemary plants die from wet roots than from cold temperatures alone. Amend heavy soil with generous amounts of gravel, coarse sand, or perlite. Raise beds or plant on slopes to ensure water drains away from roots. A gravel mulch around the base reflects heat and keeps the crown dry.

Water sparingly once established. Arp rosemary is highly drought-tolerant and actually develops stronger flavor when grown lean. Feed minimally—a light top-dressing of compost in spring is sufficient. Prune lightly after flowering to maintain shape, but never cut into bare wood, as rosemary does not regenerate from old stems. In zone 6, provide a winter windbreak and avoid late-season pruning that stimulates tender new growth.

Rosemary repels carrot fly, cabbage moths, and bean beetles with its strong aromatic oils. Plant near brassicas, carrots, and beans for pest protection. The volatile oils mask the scent signals pests use to locate host plants. Grows well alongside other Mediterranean herbs like sage, thyme, and lavender that share similar low-water, lean-soil requirements. Avoid planting near moisture-loving herbs like basil and mint.

The Society Table

Sage belongs beside it. Basil doesn't.

Old growers' knowledge, checked against Arp Rosemary's real companion table below — test any plant you're growing.

Grows well in the company of · 3

SageThymeLavender

Keep apart · 1

Basil

Plant Arp Rosemary with good neighboursThe planner flags conflicts before they're in the ground

Plant in well-drained, lean to moderately fertile soil with pH 6.0-7.5. Amend clay soils heavily with grit, coarse sand, and perlite. In cold zones, raised beds with excellent drainage are essential for winter survival. Minimal fertilization—a light compost top-dressing in spring is sufficient. Excess nitrogen produces soft, cold-susceptible growth. In containers, use a mix of potting soil with 40% perlite and top with a layer of gravel for drainage.

Ideal Temperature

Hardiness Zone Compatibility

Harvest Arp rosemary year-round by snipping 10-15cm stem tips, cutting just above a leaf node or side branch. Never remove more than one-third of the plant at once. The piney, slightly camphor-like flavor is excellent for culinary use. Spring growth has the most delicate flavor, while summer-hardened stems carry more intense aromatic oils. Avoid harvesting in late autumn in cold zones, as new growth needs time to harden before winter.

Storage & Preservation

Fresh rosemary keeps 2-3 weeks refrigerated wrapped loosely in a damp paper towel inside a sealed bag. For longer storage, stand stems upright in a glass of water on the counter like a bouquet. Dry by hanging bundles upside down for 1-2 weeks—rosemary dries easily and retains flavor well. Strip dried leaves from woody stems and store in airtight jars for up to one year. Freeze whole sprigs directly in freezer bags. Infuse in olive oil, vinegar, or spirits for flavored condiments.

Troubleshooting Common Problems

Winter death is almost always caused by wet roots rather than cold temperatures—improve drainage as the primary winterization strategy. Dieback of branch tips in cold winters is normal; prune dead wood in spring but wait for new growth to confirm which stems are alive. Leggy, sparse growth indicates insufficient light—move to full sun. Indoor overwintering often fails due to low humidity and insufficient light; use a grow light and mist occasionally.

Growing Tips

1. Plant Arp rosemary in the sunniest spot available, ideally receiving at least 6 to 8 hours of direct sunlight daily for the best flavor and growth.
2. Ensure excellent soil drainage by amending heavy clay soils with coarse sand, perlite, or planting in raised beds. Rosemary roots rot quickly in waterlogged soil.
3. Water deeply but infrequently, allowing the soil to dry out completely between waterings. Overwatering is the most common cause of rosemary failure.
4. Maintain soil pH between 6.0 and 7.5. Rosemary thrives in slightly alkaline conditions and benefits from occasional lime applications in acidic soils.
5. Prune lightly and regularly throughout the growing season to maintain a compact shape. Never cut more than one-third of the plant at once.
6. Avoid heavy nitrogen fertilization, which promotes lush but less aromatic growth. A light application of balanced fertilizer in spring is sufficient.
7. In zones 6 and colder, plant Arp rosemary near a south-facing wall or foundation to benefit from reflected heat and wind protection during winter.
8. Improve winter survival by mulching with gravel or crushed stone rather than organic mulch, which retains moisture around the crown and can cause rot.
9. Propagate new plants from 4 to 6 inch stem cuttings taken in late spring or early summer for the highest success rate.
10. Space plants 24 to 36 inches apart to allow adequate air circulation, which helps prevent powdery mildew and other fungal diseases in humid climates.