What is wrong with my blueberry bush

Question: I have a bluecrop blueberry bush planted in 2020 that is having issues, it fruited this year but many berries are already shriveling. There are bright red spots on the leaves and many berries look like the have holes in them so I am suspecting an insect, but I don’t know what to do to help the plant. Many berries seem grainy inside (eggs?).

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied June 14, 2023, 9:38 AM EDT
response: Hi,  At this point we don't see a distinct indication of a pest or disease, so you can monitor the plant for any changing symptoms and send us more photos. You can attach them to this reply.  Birds can peck holes in the berries so that damage isn't enough to determine the culprit from them, unfortunately.  The red leaf spotting might be an abiotic issue due to plant stress, maybe due to the dry drought like conditions we have had. It is less likely a nutritional issue. Blueberries prefer to stay evenly moist, so if you aren't already we suggest you monitor closely during this drought for watering needs. You should feel the soil first about 4 to 6 inches down at the base of the plant and give them a god long soaking if they need it. Then let them dry a bit in between. You don't want the soil saturated but also don't want it to be bone dry by the next watering time.  NC State Extension has a leaf diseases of blueberry page where you can compare the leaf symptoms but this article appears to be geared more towards commercial operations, but it has helpful photos of different leaf spots you can see. If the red spots turn brown, that might suggest an infection, but if they remain red, that suggests an abiotic stressor instead. A laboratory soil test can help assess the soil's acidity and nutrient content if you haven't done one in a few years. Is this a solo plant? Fruit set isn't as robust on plants lacking a pollinator, even though blueberries have some capacity to fruit by themselves from bee pollination. If this plant had cicada damage from a couple years ago, those stem injuries might have contributed to plant stress, even if they weren't bad enough to cause stem dieback or require pruning those cicada scars off. You can check the stems for any scarring.  Penn State has a good webpage about keys to establishing a successful blueberry planting that you could check to make sure you have these environmental conditions achieved.  Let us know if you have changes and feel free to reach back out.  Emily

responder: The Question Asker Replied June 14, 2023, 12:27 PM EDT
response: Hi,Thanks for looking at this. The bush is still only a few feet tall so I have it covered with a chicken wire dome, the birds cannot get to it (however before I put the dome up the deer did munch quite a bit off the plant so only about 1/3 to 1/2 bloomed.) I have been carefully watering it for the past month, however I did check the soil this year and found it was not as acidic as it should be (roughly neutral ph). I have bought a soil acidified and treated it twice. I wonder if I was overwatering when it bloomed because I did water once before we got quite a bit of rain in April or May. I have 2 other bushes, one is a chandler which has been dying. It did not produce fruit last year and has even fewer leaves this year. My suspicion is that the soil was the issue. I have been watering it and also treated it with soil acidifier. One branch had leaves that turned brown and died on the plant. I am not sure I will be able to save that one, but the current leaves do look green and healthy.My third is a blue ray. It seems happy and has already produced several delicious berries and I don’t see major issues with it (although the deer got a bit out of that one too.)I worry about the red spots since they seem concentrated on the older growth (not the branches that have grown since the deer pruned the bush for me.)All 3 plants had cicada netting. But they didn’t seem happy about that.~Rachel On Jun 14, 2023, at 9:38 AM, Ask Extension <<personal data hidden>> wrote:﻿

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied June 14, 2023, 3:52 PM EDT
response: Hi Rachel,  You can refer to our webpage on lowering soil pH for blueberries and also Penn State has a good reference about soil pH for blueberries. It often takes some time for the pH to adjust after applications have been made. Also mixing down into the soil about 6-8 inches would be helpful as well if you are planning on replacing the plants or if you want to try to keep adjusting the soil for the existing plants just make sure the watering is going well to help it leach down into the soil. What have you used for an acidifier?  Protecting the plants from deer and rabbits is good to help them get established, since wildlife can really take a toll on the young plants.  We will confer for some more recommendations with our edible fruit expert with any further guidance.  Emily

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied June 15, 2023, 3:41 PM EDT
response: Hi- The large number of small, open fruits may have been caused by poor soil conditions (e..g., low organic matter, high soil pH, low soil moisture, lack of nutrients) and/or low pollinator activity during bloom.   Flowers and fruits should be removed for the first two years after planting to help establish a strong root system.  As noted, blueberry leaves will become discolored with spots and blotches when plants are stressed. The symptoms can be difficult to distinguish from those caused by diseases.  Jon

responder: The Question Asker Replied June 19, 2023, 8:35 PM EDT
response: Hi,Thank you so much for looking at this with me. I really think it is a bug, the berries have a single hole and when cut open have grains. I even had one that looked like it had a small white worm. I have photos of some that had grains but I didn’t get a photo of the worm. Only berries with a hole are like this and there were a few on both bushes. Is there a way to spray for whatever this is without hurting bees? Do you know what the bug might be?~Rachel On Jun 15, 2023, at 3:41 PM, Ask Extension <<personal data hidden>> wrote:﻿

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied June 20, 2023, 1:39 PM EDT
response: Hi- there are several insect pests of blueberry fruit. If they are feeding inside the fruits you should be able to see see the maggot(s). A hand lens or magnifier will help you see them. If you see an exit hole it's more likely to be blueberry maggot. Blueberry maggot- https://hort.extension.wisc.edu/articles/blueberry-maggot/  Spotted wing drosophila (SWD) is a fruit fly best that feeds on blueberry. The females make a slit in the blueberry skin where they insert their eggs.   Detailed UGA web page on the topic-  https://site.caes.uga.edu/blueberry/swd/  To control SWD you would need to spray spinosad or pyrethrum when berries begin to change color from green to purple. Jon