Herb / Warm season
Rosemary
Woody shrub herb that dies from kindness, not neglect
Plant out byJun 1zone 6
- Family
- Mint (Lamiaceae)
- Sun
- Full sun (6+ h)
- Difficulty
- Fussy
- Days to harvest
- 80-180 days
- Spacing
- 24 in apart, rows 36 in
- Pot size
- 3 gal pot (great in pots)
- Frost
- Half-hardy
- Start
- Start indoors
- Water
When to plant
Showing .
Averages for a typical garden in the region. Your local frost dates may differ by 2-3 weeks, check a local source.Wait until Feb 9
In zone 6, start seeds indoors Feb 9 to Feb 23; plant out May 4 to Jun 1. Average last frost Apr 20, first fall frost Oct 20.
Units
More rosemary dies from water than from drought. The roots rot fast in soggy soil, and a pot that stays damp all winter is the usual end. Let the top inch of soil dry before you water again. Use a fast-draining mix, a pot with real drainage holes, and the sunniest spot you have.
Cold is the other limit. Rosemary is reliably perennial in zone 8 and warmer, and most kinds handle temperatures down to somewhere around 15 to 23 degrees F. North of that, grow it in a pot and carry it inside for winter. Indoors it wants your brightest window and a cool room. Warm, still air inside a house invites powdery mildew, a white dusty film on the needles. Water even less while it rests, and run a small fan nearby if mildew shows up.
Seed is slow and sprouts poorly, and a seed-grown plant can take most of a year before you cut much. Most people buy a small plant or root a cutting, which takes easily. Plant outside well after your last frost, once the soil has warmed to around 70 degrees F. In the ground, give each plant 2 to 3 feet, since it turns into a small shrub over a few seasons. Mine lives in a pot by the grill and gets clipped every time burgers go on. Snip sprig tips and leave plenty of green behind.
Things to consider
- Start a young plant in a pot 6 to 8 inches wide and move up one size as it grows. A pot far bigger than the roots holds extra water, and that wet soil is what usually kills it.
- Some varieties are sold as extra cold hardy for zones 6 and 7. Even those do best in a sheltered spot near a wall, with winter mulch over the roots and good drainage below.
- Bees work the small blue flowers, so leave a few stems uncut when it blooms. Harvest from the other side of the plant and you still get plenty for the kitchen. The flowers are edible too, with a milder taste than the leaves.
Good neighbours
Pests to watch for
Powdery mildewRoot rotAphids
Questions about growing rosemary
Why is my indoor rosemary turning brown?
Usually the roots stayed wet too long, or the pot dried out completely and the roots died back. Check the soil with a finger before every watering. Growth slows in winter, so it needs much less water then. A bright, cool window helps more than any fertilizer.
How do I root a rosemary cutting?
Cut a 4 to 6 inch tip of soft new growth, strip the lower leaves and push the stem into moist potting mix. Keep it bright but out of hot sun. Roots usually form within a few weeks. A gentle tug that meets resistance tells you it has rooted and can move to its own pot.
Can I plant rosemary with other herbs?
Yes, as long as they also like dry soil. Sage and thyme share its taste for sun and sharp drainage, so they make good pot partners. Basil and mint want more water, and one of the two plants will suffer if you share a pot. Give the thirsty herbs their own containers and group the dry lovers together.
Save this crop
Pin it to a garden board so it is there when planting time comes round.
Similar crops
Sources
General guidance for home gardens. Frost dates are averages for a zone or region; check a local source (in the US your county extension office) for local timing.