What's wrong with my rosemary?

[Salaam]

Hello all,

Another in my what's wrong series! The leaves have curled, have white spots, and the whole plant looks sickly. I always have problems with rosemary.

Salaam

[Labradors2]

Rosemary prefers a light, well-drained, alkaline soil. It doesn't like to be over-watered. Perhaps you have been loving it a little too much (with the watering?)

Linda

[Salaam]

I think I've watered it once. We've had a lot of rain here and no watering was needed. I think there's only an organic potting mix in pot .

[Worth1]

They hate nitrogen.
Worth

[PhilaGardener]

Might be mildew - give it lots of fresh air and sunshine! As others have said, not too wet (if you have a lot of rain, maybe move under a protective overhanging roof edge?), not too dry, and no fertilizer. Good luck!

[dmforcier]

I think your dirt is too good. Fill a pot with caliche and top with some nice flinty rocks. Then neglect water and fertilizer. Then watch it smile.

[oakley]

Powdery mildew. Doesn't look too bad yet. Very common. Wet feet and too good of a
fresh fluffy soil. Especially if it has moisture control.
I can't over-winter rosemary so i pick up a nice fresh grown plant like yours every
season. It goes right into a pot that grew something else last year. Nice spent soil, good
drainage, sometimes add some sand. No mulch. No food.

For a cure i believe potassium bicarbonate is the best solution. It is a contact fungicide
and will kill off the fungal spores.
I use baking soda on my zucchini but it is only effective as a preventative. Not a cure.

Seems counterintuitive to use water, but laying the pot on its side, spraying heavily to
prevent the puffy loose spores from sticking like a good bath, then spraying...
and get it in some wind to dry off quickly.

And changing the soil will keep it from coming back. Cheap stuff. Dirt. Loves sun but not
wet feet. Mimic dessert dry conditions. And ignore. If you can't move it out of the rain,
cover the soil of your pot with something, like a plastic sleeve so it doesn't get a
constant saturation. Mine is doing just fine in old soil even with some good storms.

Some use a milk spray or dilute vinegar, even mouthwash.

[Worth1]

Cactus mix works good.
Worth

[Labradors2]

What Oakley said sounds great!

Reminds me that I finally discovered how to grow Lavender, another med. native. It likes gravel and sand, and drought. I gave it what it needs by planting it along the side of the house under the eaves in builder's sand. Finally, it is happy! I bet Rosemary would love it there too!

Linda

[dmforcier]

Rosemary really likes full sun, though it will do well enough in bright shade.

[bower]

Rosemary also thrives as a houseplant, for the dry soil and neglect that it gets - although it will also get leggy for trying to climb out the windows towards that sun!

My rosemary is huge and a shocking shape... I just potted up to a ten gallon container and a summer in the greenhouse, but I need to air layer and root the gazillion disoriented side shoots.

[dmforcier]

Think it could be trained to be a living, and really good smelling, Christmas tree?

[bower]

Originally Posted by dmforcier

Think it could be trained to be a living, and really good smelling, Christmas tree?

It's shaped more like a sled, with maybe twenty reindeer pulling it....

[Salaam]

Well, I don't know if I have time to change the soil. Maybe mix some sand into it. But I'll be sure not to water it and not to add any compost or fertilizer, ever! It's better the last couple of days as we've finally been getting sun.

By the way, there are folks here who overwinter in ground! Some also are able to overwinter inside. It's very hit and miss, I gather.

[bower]

I think some varieties of Rosemary are touted for hardiness, only to about freezing though so it's surprising they make it in Ottawa!

I've kept mine in the greenhouse as late as February one year, but then rescued it inside as temperatures were dropping lower. The mass that stores summer heat for the longer term is only enough for a mild winter after a hot summer, but we don't seem to be getting that combo much!

Other woody mediterranean herbs overwinter here very well with some dieback depending on how harsh a winter. I have thyme and sage plants that have kept going for 20+ years. Hyssop (which is the closest thing to an alternate for rosemary) is a bit less hardy and also seems intolerant of weeds or other competition so needs a bit more care... I had to replant once in the same time period.