Cotoneaster Sunburn or Fire Blight?

[Apex37]

I have this cotoneaster that kinda just out of nowhere started browning really badly. I originally thought maybe sunburn as it’s been very hot, so I moved it to a more shaded spot on my patio, but it seems to be continuing it’s downward trend. I’ve definitely kept it well watered, maybe too well watered. Thinking back to when I picked it up at the nursery just a couple months ago, it was kept in full sun and they had it there for awhile. I’m starting to suspect something more sinister going on.

Any thoughts or suggestions?

 

[penumbra]

Has it been root worked lately? If not, it probably is fire blight. I have lost a few in the past due to fire bight.

 

[Apex37]

Has it been root worked lately? If not, it probably is fire blight. I have lost a few in the past due to fire bight.

No, I haven’t done anything to it since getting it from the nursery other than watering and fertilizing every couple weeks.

 

[AJL]

Suggest you go back to the nursery and get a replacement or refund

 

[Apex37]

Suggest you go back to the nursery and get a replacement or refund

It’s been months, probably closer to 3 since I got it, so I doubt they’ll do much. It cost me maybe $20, so not a huge deal.

 

[Michigan Tree Murderer]

It’s been months, probably closer to 3 since I got it, so I doubt they’ll do much. It cost me maybe $20, so not a huge deal.

Have you checked it for pests? Mine loves full sun and the aphids like my cotoneaster.

 

[Hartinez]

Don’t hold hope for this one. I have found Cotoneaster to be not so good. Though, I do usually work the roots pretty hard. They look great, look great, then boom, they look like this. I’ve tried systemics, foliar and what feels like everything else. I really think it’s me over working the roots.

 

[Carol 83]

I have found Cotoneaster to be not so good.

Me too. I had two. They looked good and were doing fine until all of sudden they didn't and weren't. I didn't even repot.

 

[Scorpius]

I treat Cotoneaster like I do fruit trees. Lots of preventative maintenance. I use Bonide infuse and four other fungicides that I rotate out on the foliage. Lots of sun and lots of air movement for these guys in my experience. They start to decline rapidly in shady locations.

 

[milehigh_7]

Man, I love this genus but this is exactly what happens to me every.single.time. If someone can solve this puzzle, I would love to hear it.

 

[Hartinez]

Man, I love this genus but this is exactly what happens to me every.single.time. If someone can solve this puzzle, I would love to hear it.

Every time for me also

 

[Lutonian]

if it is fire blight you can use a streptomycin based spray as fire blight is bacterial, but fire blight symptoms and root damage symptoms can look very similar. see if you can send a plant sample to your equivalent of DEFRA for diagnosis if this is a reoccurring issue in your garden.

fire blight can effect lots of plants in the rose family ume, pear, apple quince and others.

I would isolate that tree and check the roots and reevaluate the horticultural care these have been given as a lot of times people think they have all sorts of diseases but in reality it is there care that has caused the issue.

I have done this with maples myself, i thought had a fungus but turned out to be too wet in the root core, I changed my watering for the rest of the year and repotted into better soil in spring no more issues.

 

[jradics]

I have this cotoneaster that kinda just out of nowhere started browning really badly. I originally thought maybe sunburn as it’s been very hot, so I moved it to a more shaded spot on my patio, but it seems to be continuing it’s downward trend. I’ve definitely kept it well watered, maybe too well watered. Thinking back to when I picked it up at the nursery just a couple months ago, it was kept in full sun and they had it there for awhile. I’m starting to suspect something more sinister going on.

Any thoughts or suggestions?

every time i even hear the word Cotoneaster, I immediately think of massive spider mite infestation

 

[Esolin]

I have done this with maples myself, i thought had a fungus but turned out to be too wet in the root core, I changed my watering for the rest of the year and repotted into better soil in spring no more issues.

Agree with this. I've lost every cotoneaster I've bought, and several awesome pyracantha that are in the same rose family, to summer root fungal issues. The plants looked great, then boom, suddenly branches start wilting/browning in the heat of summer no matter much I water, until the whole plant is dead. My conclusion is that Rose family plants just can't take having their roots be both damp and hot. It could be fireblight (which is also usually triggered by hot temps) or, it could be another fungus making the roots rot. I have trouble believing every single plant I had bought (from different nurseries) was infected with fireblight, so I'm guessing heat + damp just makes them vulnerable to any fungal root rot.

I'm honestly not sure how to save a plant that that's already at the point of failure, but I've heard others on here say they started planting their cotoneaster/pyras in coarse free draining soil like %100 pumice, and that this solved the problem. It helps the roots stay cooler and drier during the summer heat. I have two pyras left. One is in a more regular mix, and the other is in pure pumice. The one in regular mix is starting to show some of this typical heat/root issue stress. The one in pure coarse pumice is holding up much better. A few of the oldest leaves are showing brown spots, but no full on branch die back.

My best advice would be to try and keep the roots as cool as possible and if is suvives, repot it in the Spring in free draining soil. I've also heard some bonsai folks say they started covering their bonsai pots with white towels in the summer to reflect some heat away from the roots and that it helped with heat stress. Maybe? Best of luck.

 

[queenofsheba52]

Oh man, so sorry to read this. I love cotoneaster and it grows like a weed in my yard, but I also have lost every one I tried to work...just like you described: good, still good, still good, bad, dead.

I'm going to try again, because they are just so stinkin' cute, and will be more mindful of the heat aspect.

 

[Apex37]

Yeah, unfortunately this one, and another small cutting I had didn’t make it. It’s been a rough year this year. I’ve had more plants die in my second year doing this hobby than my first.