The good graces of rosemary

Now don’t get me wrong. Rosemary is an incredible plant.  It grows happily in the toughest, poorest conditions, flowers in the dead of winter and instead of giving off airs of one that’s surviving with gritted teeth, has the grace to wrap itself in the rich fragrance of nana-roast.

But it’s one of those irritating plants for which there’s really no great moment to prune.  The traditional wisdom with flowering plants is to prune as soon after flowering as possible (except that stuff which flowers after about mid-summer – but hang on – if I get distracted with all the exceptions to the rule now I’ll never get around to the point).  The idea is to give as much time as possible for the plant to put on new growth before it’s time for next year’s flowering.

Rosemary stuffs the rule by reaching its peak of flowering in late winter, while simultaneously putting on a great burst of growth.  If you wait until it has finished flowering, it feels like you’re cutting off the greater proportion of new growth that this season is likely to produce.  If you don’t prune, the plant gets to tall, or too big, and starts to lose a lot of the charm that made you want to grow it in the first place.

Take the form ‘Tuscan Blue’ for example, shown in most of these pics, and grown primarily for its rigidly upright form.  There are very few shrubs that do this strictly vertical thing, so I use it a lot.  In order to retain those strong lines at the height you want, you’ve got to be pretty brutal with it, and reduce it to virtual stumps (at least by two thirds of its height) each year, otherwise you’ll end up with bare-legged clubs of blue flowers 2m tall.

You don’t have to be quite so strict with prostrate forms like Rosmarinus ‘Blue Lagoon’, as you’re not depending on maintaining that youthful form.  But there’s still something of a dilemma about the timing of a hard cut, which is likely to be motivated by the need to reduce its spread, or to minimise the amount of dead wood that’s accumulating over the years.

There’s no easy solution.  There’s absolutely nothing to be done but to cut it hard right when you’re enjoying the flowers, or to wait a few more weeks, and sacrifice a whole lot of new growth.  I try and strike a balance, myself, but never feel entirely settled with the decision.  Thankfully a forgiving nature is high on rosemary’s list of virtues.


  1. Great to see how you can use rosemary ‘Tuscan Blue’ in the landscape. Mine have always been straggly and untidy. Now i realise that if i’d pruned as you suggest i would have a marvellous vertical element.

    1. It seems that non-intervention is just not an option with rosemary..

  2. I think we also need to recognise that Rosemary is not long lived and like lavender old woody specimens have no charm and deserve to be replaced . Older shrubs that have not been routinely trimmed will not respond when pruned into old wood.Make way for the young!

    1. You’re dead on – and that rosemary was made for a harder life than our gardens usually provide. They grow faster, bigger and uglier in the garden, and have a shorter life-span than in the starved conditions of the wild. Having said all that, I can think of some fabulous, gnarled old specimens that deserved to be revered.

  3. I agree. My favorite way to prune them is from the bottom up, in order to show off their beautiful internal structure, rather than trying to make them look like a boxwood hedge or something.

  4. I have a Tuscan blue rosemary hedge.It was planted 1 year ago. Im having trouble with it dying back in patches .Its well drained and has normal water.its frustrating as Idont know what the problem is .If anyone has any answers Id appreciate a reply

    1. Hi Monica
      I know that a lot of rosemaries have these issues, and they seem to be more prevalent in the relatively rich setting of a garden, than elsewhere. I’ve heard there are resistant varieties, but am yet to see any evidence for this. So far it’s all just anecdotal

  5. Hi Michael,
    I want to plant a Rosemary hedge but I’m wondering if it can be kept small? I don’t want it more than about 30cm tall, as a want to plant unclipped/freeform lavender behind it…the garden is not very wide either…
    Btw love your articles in GA mag…

  6. […] Rosemary also has a tendency to flower outside its normal flowering season; it has been known to flower as late as early December, and as early as mid-February (in the northern hemisphere). (3) […]

  7. Just stumbled on this comment thread, Michael. The Diggers Club advertise a dwarf form of Rosmarinus officialis with no cultivar name which they say has

    ‘…all the good habits of ordinary rosemary for culinary use, hedging and late winter flowers this little beauty never grows taller than 70cm making it the ideal small hedge around the vegetable or herb garden.”

    Maybe a solution? would still need pruning but maybe not so vigorous.

    1. Thanks Emma
      I’ll check it out. Too many of the really prostrate forms compromise on colour, but I’ll have a look

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