ReadyRen
Newly Registered
Posts: 1
Joined: Thu Jun 30, 2011 8:42 pm
Location: North Phoenix

Blueberries looking like they got sick

I have some blueberry bushes I started awhile back and for awhile they looked VERY healthy. Then I moved them next to the home so they would have afternoon shade now that the temperature has gone over 110 here and within a week they developed some brown or reddish spots on the leaves.

Does anyone know what might be causing this and is there a way to cure / prevent it?

The blueberries are planted in 12" containers wit ~50% Sphagnum Peat Moss, and 35% Forest Hummus with a little Perllite, Vermiculite and coffee grounds. The soil PH comes in at 5.3 or so.

Everything I have found for a treatment is pull and burn them. I'm concerned since that doesn't help prevent the next occurrence and possibly it is curable. If the severe treatment is needed should I discard the soil as well or compost it / reuse it?

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CharlieBear
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Posts: 590
Joined: Thu Jul 14, 2011 9:19 pm
Location: Pacific NW

Can't tell for sure from picture but here are some things to consider. Blueberries are "native" to main and the pacific NW. If you decide to destroy and start again:
1) get larger self watering pots, those are too small, they could have gotten root bound and heat stressed in such a warm place.
2) Mulch them well with sawdust, pine needles, something like that. Blues are very shallow rooted, so also be careful if you have to pull weeds, hand only
3) Next time move into afternoon shade at about 90 to be safe.
4) don't fertilize them until they are established period then use organic azelea type fertilizer in very early spring and then about 2 months later again in moderation.
5) in such a warm dry climate you will have to water them nearly year around except maybe when they are really dormante
6) consider a southern low bush variety, they will take a little more heat.
7) put fresh mulch on early every spring as blueberry type pathogens tend to "hybernate" in the soil and when you water or it rains "spring" back up on the plant
8) If you use regular pots water very early in the morning not after it is already hot

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Kisal
Mod Emeritus
Posts: 7648
Joined: Tue Jun 24, 2008 5:04 am
Location: Oregon

ReadyRen, it does look like blueberry rust to me. Usually, the fungus requires hemlock trees as an alternate host, but I found [url=https://www.fruit.cornell.edu/berry/ipm/ipmpdfs/BB%20leaf%20rust%20fast%20fact.pdf]this article[/url] that mentions blueberry rust in areas where hemlocks and evergreen blueberries are absent.

I'm not sure that you have to destroy your bushes right away. Before doing so, you might want to check with the nearest Extension Service office. They are usually listed in the White Pages of the phone book.

It's possible that, if there are neither hemlocks nor evergreen blueberry bushes in the area, that the fungus won't be able to survive. Apparently, the fungus only harms the following year's crop, anyway, so you might be able to get some berries this year.
"Isn't it enough to see that a garden is beautiful without having to believe that there are fairies at the bottom of it too?" - Douglas Adams

cynthia_h
Super Green Thumb
Posts: 7501
Joined: Tue May 06, 2008 11:02 pm
Location: El Cerrito, CA

I'd like to add that blueberries require acid soil. The Extension Service may be able to offer you soil-testing services and inform you whether your soil/planting mix is sufficiently acidic.

Cynthia H.
Sunset Zone 17, USDA Zone 9

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