My rosemary plant is finally reaching the end of its days. A good metre and a half tall and wide, it has been a focal point in my veg garden for a long time and I’ve been trying to figure out how old it is – it can’t be more than nine years old, and I know it was already well-established before the pandemic hit, so by my reckoning I must have planted it in 2017/2018.
I can tell that it is winding down as slowly, sprig by sprig, it has been turning yellow and then brown-black as the needles die. My plan is to dig it up and plant a new one in its place soon, probably in the next week or two.
I mentioned this to a friend and they looked a little horrified. They asked why I didn’t just leave it to see if it would recover with time. So I explained:
As a general rule, you can expect a five to ten year lifespan from a rosemary plant (assuming it is planted in the ground, rather than a pot in which case it may have a slightly shorter life expectancy.) You may find a rosemary plant dies earlier than anticipated if the soil gets very waterlogged – the roots will start to rot and it can no longer survive. Given the age of my rosemary plant, and the speed with which the branches have been dying back, I’m confident that it wouldn’t recover.
If you have just a branch or two on a rosemary plant that have died back, the rest of the plant may remain healthy, so unless it is at the older end of the spectrum I’d suggest pruning the dead branches and leaving it to see if the plant continues to thrive. If you’re losing more and more over a couple of months, that would be more of an indication that it is on the way out.