When to plant rosemary in Eugene, OR

Plant young rosemary plants in Eugene Mar 15 – May 3.

Moderate Plant young plants

Difficulty: Moderate
Sun: Full sun
Spacing: 24 to 36 inches apart
Planting depth: Plant at the depth it grew in the nursery pot
Frost: Handles light frost; wet winter soil is the bigger risk
First harvest: Pick sprigs a few weeks after planting, once new growth appears

Why these dates

Eugene's typical last spring frost is April 11. As a cool-season crop that handles light frost, this crop doesn't need to wait for that date. In the west-side valleys, though, the soil usually isn't ready to work until about March 15.

West-side valleys. The Willamette Valley, Puget Sound and southern Oregon valleys. Long frost-free seasons, but soil stays cold and wet into May, so warm crops wait for warm soil, not just the last frost.

How to grow rosemary in Eugene

Pick a sunny spot with soil that drains well, and mix in an inch or two of compost.
Plant young rosemary plants Mar 15 – May 3, 24 to 36 inches apart. Plant at the depth it grew in the nursery pot.
Water until established, then only in dry spells. In cold eastern areas, grow it in a pot and move it to a cool, bright spot for winter.
Harvest: Snip sprig tips as needed. Don't cut back into bare wood; it won't regrow.

Key numbers

Wet winter soilTop killer
15–20°FMost types hurt at
Arp, Madeline HillHardiest
None neededFertilizer
Only into green growthPrune
Terracotta, gritty mixIn pots

How it works

The plant biology behind the advice above, in plain language.

Wet soil kills more rosemary than cold

Rosemary comes from dry, rocky hillsides around the Mediterranean. Its roots rot when they sit in cold, soggy soil, which is why more rosemary dies in a wet Northwest winter than in a cold, dry one. Plant it in fast-draining soil, on a slope or in a raised bed, and never in a spot where water pools. Mixing gravel into heavy clay helps.

Cold hardiness

Most rosemary varieties are damaged somewhere around 15 to 20°F. Hardier selections like Arp and Madeline Hill (also sold as Hill Hardy) survive colder winters, especially in well-drained soil. Cold, drying winds make damage worse, so a spot near a south-facing wall is ideal. In colder eastern areas, grow rosemary in a pot and move it to a cool, bright spot for winter.

Soil and feeding

Rosemary grows best in lean, well-drained soil and tolerates neutral to slightly alkaline pH. It doesn't need fertilizer. Rich soil and extra water make it grow fast and soft, with less of the aromatic oil that gives it flavor. Once established, water only during long dry spells.

Pruning

Rosemary has very few dormant buds on old, bare wood, so cuts into leafless stems usually don't regrow. Prune lightly, within the green, leafy part of each stem, right after flowering in spring. Regular light trims keep it compact and stop it from getting leggy.

In containers

Use a terracotta pot, which dries out faster, and a gritty mix like cactus potting soil. Water when the top inch or two is dry. Indoors in winter, rosemary needs a cool, very bright spot; warm rooms and low light lead to powdery mildew and leaf drop.

Common questions

When is the last frost in Eugene, OR?

Typically April 11. In 9 years out of 10, frost is over by May 9. These are 1991–2020 NOAA climate normals for Eugene Mahlon Sweet Airport.

Is it too late to plant rosemary in Eugene?

The spring planting window runs through May 3. Later plantings tend to struggle in summer heat.

How long until I can pick rosemary?

Pick sprigs a few weeks after planting, once new growth appears. Snip sprig tips as needed. Don't cut back into bare wood; it won't regrow.

Why did my rosemary die over winter?

Most often from wet, cold soil rather than cold alone. The roots rot in waterlogged ground. Replant in fast-draining soil or a raised bed, and choose a hardier variety like Arp.

Can I leave potted rosemary outside in winter?

West of the Cascades, usually yes, if the pot drains well and sits against a sheltered wall. In colder areas, roots in pots freeze more easily than in the ground, so move the pot into an unheated garage or other cool, bright spot during hard freezes.

How do I fix leggy rosemary?

Prune lightly within the green growth after flowering, and repeat every year. Cuts into old, bare wood rarely regrow, so very woody plants are often best replaced.

Also plant in Eugene around the same time

Planting dates for rosemary in nearby areas

Portland, OR Mar 15 – May 3
Gresham, OR Mar 15 – May 3
Wilsonville and Canby, OR Mar 15 – May 3
Salem, OR Mar 15 – May 3
Roseburg, OR Mar 15 – May 3
Medford, OR Mar 15 – May 3

Full planting calendar for Eugene · Rosemary in every city