This guy was planted per instructions/best practices about 3 months ago. It's about 1 foot in diameter, it's in a decent partial-shade/partial-sun location, and I have supplemented with liquid plant food twice (every ~4 weeks) during this time. I am in North Texas where it is pretty hot and humid at this point.

It was healthy for a while, but over the last 4-6 weeks it began struggling and now looks like this: (broken link - file has been deleted).

There were some heavier rains for a while and ground may have been too wet/over-watered for several days (maybe a week?), but that's all I can think of that would have upset it. Are the blackened leaves indicative of fungus or pests?

  • 1
    Are you sure you photo shows a Hosta? Only it looks like Aucuba japonica and not a hosta at all....
    – Bamboo
    Aug 10 '20 at 10:02
  • @baboo...that's right (good eye!). I looked at tag without my glasses and at that point, "hosoba" looked a lot like "hosta", which I bought at the same time and was listed on the receipt I checked :--( I've updated title. Issue is the same, though...
    – mblatz01
    Aug 10 '20 at 14:29

Now it's established that the plant is actually Aucuba japonica, the problem may well be related to being too wet for too long. The blackening of the leaves, in this case, is possibly a phytophthera root rot, but the usual cause is most often related to being too wet in winter. There is no treatment - the plant might recover and grow on well, or it might not.

Remove blackened leaves, cutting out the stem/s they're on at the base. Stop feeding now, and don't give it any more till next spring. If you think you may have planted it somewhere that frequently gets too wet, or the soil there is very heavy and not free draining, you may need to move it to a better position which drains down more freely. These shrubs usually reach 8 x 8 feet or more; they do well in very shady areas and in dry soils once established, but will also do fine with some sun, though not so well in full sun all day in hot regions of the world (especially in summer). However, they really do not appreciate being too wet at the root. Further info on this plant generally, and leaf blackening in particular, here (though its a UK link) https://www.rhs.org.uk/advice/profile?pid=314#:~:text=to%20apply%20pesticides.-,Cause,rots)

  • "though its a UK link" Nothing wrong with a UK link! ;--) I lived in the docklands are for ~4 years, and made weekly trips up to Northampton, so I have many "links" to the country :-) And thanks for all the help throughout my recent posts, BTW!
    – mblatz01
    Aug 10 '20 at 17:53
  • RHS is a very good source, but may have UK-centric information - sometimes not helpful in other regions of the world where conditions (and problems) may be different, that's all I meant! Though I have to tell you, the way the UK is going, its not gonna be the place it once was... sadly
    – Bamboo
    Aug 10 '20 at 21:10

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