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I planted a jasmine (polyanthum I think) in our backyard last spring. It is positioned in a corner where it gets 2-3 hours of sun on a sunny summer day, but this being the Netherlands, that remains only a theoretical possibility most of the time.

We had a cold spring last year, and the plant was initially stunned by the cold, as I forgot to acclimate it. But then it started to grow spectacularly and is now about 2.5m high. I fed it through the growth season two or three times with a balanced fertilizer.

Since mid-autumn this year, some of the leaves in a waist-high section started going gray. I somehow assumed that since it was the end of season it was going to shed its leaves, but it hasn’t. The gray/black leaf issue continued spreading, though, and it increasingly looks like a disease (see photos).

closeup overview

I can’t figure out what the problem is just by looking at the photos online. Cold? Fungal disease? Root rot? Blight? Malnutrition? Overwatering? And does this problem need a remedy, or should I just wait for the spring to come?

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  • Did you have an unusually cold snap in mid autumn (as happened in the UK) followed by very wet weather, or just lots of wet weather? How are newer leaves doing on the plant, has it been affected?
    – Bamboo
    Feb 13, 2022 at 16:31
  • Yes it was cold, but not one night below zero here. There are no new leaves yet. Now I wonder whether polyanthum is winter hardy enough.
    – retrography
    Feb 13, 2022 at 22:35

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Jasminum polyanthum is not fully hardy - it will usually tolerate down to about 5 degrees C for a short period without much harm, but lower temperatures, despite it being an evergreen plant, will likely cause leaf damage/loss and possibly die back to the roots. They may recover and regrow in spring, but a very cold winter will kill the plant outright. It is more suited to a glasshouse or conservatory rather than outdoors, although they can survive for some years in warmer areas like cities (i.e. London UK) if grown in a sunny, sheltered spot. It's possible the greying of the leaves is due to cold - the black spots may be fungal problems from wetter weather after being affected by cold, but it is rather odd that the problem did not seem to affect the top parts of the plant rather than it just being lower down; cold damage should certainly affect the upper parts as well as the rest.

I would suggest you wait and see if it recovers during spring. If the area is southfacing and fairly sunny, and it doesn't recover, Trachelospermum jasminoides, common name star jasmine (although its not actually a jasmine at all) would be a good choice to replace it; it's an evergreen, hardy climbing plant with scented white flowers which smell very like jasmine around June time.

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  • Is that a better choice than Officinale? That’s supposed to be winter hardy to.
    – retrography
    Feb 14, 2022 at 6:38
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    In my opinion, if you want to grow it as a replacement, yes. J. officinale, whilst great, spreads and becomes very dense, difficult to control - I once had to remove one that had knocked down a fence - its roots took up over 12 feet from side to side in the border, and the growth was mounded up and completely covered a 30 foot fence from end to end. Trachelospermum, whilst it does get up to 35 feet high, tends to be a little less aggressive, a neater grower. J.. officinale is also deciduous
    – Bamboo
    Feb 14, 2022 at 11:57
  • I am finally going to the garden center to buy a replacement. I am just worried that an excessively cold winter (like 2020-2021) still kills the growth on a star jasmine (or even the plant itself). According to RHS it is only hardy down to -10, and that for a short while… It’s a bit of a dilemma here whether it is worth investing time into, as I would like to see it mature one day and this feels like gambling a little bit. Any reassuring stories about that?
    – retrography
    Mar 21, 2022 at 8:06
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    I don't know where you live, but in London,UK, our star jasmine was largely unaffected by the unusually cold weather we had here in early 2018 - some shrivelled leaves here and there, but otherwise ok and the plant recovered well, so depends where you are really. A bigger issue might be the small amount of daily sunshine in that area where you want to plant - 2 to 3 hours could not be described as full sun by any stretch of the imagination, it normally means a minimum of 5-6 hours a day if there is sunlight. This would make the area colder generally for plants.
    – Bamboo
    Mar 21, 2022 at 11:12
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    South west is better; as for cold, as you say, your low temperatures were 'exceptional', so hopefully that won't happen again any time soon. Fact is, though, with climate change, unpredictability in weather patterns is kind of built in now, but if the minus 10 happened when the plant had been in place for say 5 years, its less likely to be killed compared to if it had only been in place for a year. You could always provide temporary protection if such cold temperatures were forecast again, such as horticultural fleece overnight.
    – Bamboo
    Mar 22, 2022 at 12:06

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