Blueberry bush wilting
I have four blueberry bushes. All of them are currently suffering from sunburn (browning of the leaves), but one of them may be suffering from something else as well. The tips of several canes are wilting and dying. This has always been my healthiest and best producing bush, so I'm very concerned. The berries on all my bushes this year are shriveled, and I assume this is because of the heat, although this hasn't happened to this degree in the past, so I'm attaching a picture of the berries as well, just in case it's relevant.
Josephine County Oregon
The symptoms you describe, leaf burn, wilting, and wrinkled fruit, sound like drought stress.
The OSU publication Growing Blueberries in Your Home Garden https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/ec1304.pdf
describes how much water blueberries need: (Mature) plants need from 1.5 to 3 inches of water a week. Irrigate to supplement rainfall as needed. Irrigate frequently enough to prevent the soil from becoming too dry.
Considering how hot it has been lately, and our lack of rainfall, you may need more than 3 inches, but avoid overwatering. Check the soil frequently. It also recommends maintaining 6 inches of mulch around the bushes, which will help keep the soil moist.
This Michigan State Extension article has pictures and descriptions that can confirm that your bushes are suffering from drought. https://www.canr.msu.edu/news/drought_symptoms_in_blueberries
I have no idea how this translates to inches per week, though.Can you help me out? 24 gallons a week per bush sounds like a lot and I don't want to overwater them but, apparently, I haven't been giving them enough.
Thank you for your help!
To find out how long it takes to put an inch of water on your blueberry bushes take a shallow, at least one inch deep container and put it under a dripper. Measure how long it takes to put an inch of water in it. That can guide you in putting 3 inches of water on your bushes in one week. If it takes an hour to fill one inch, then you know to run it over the course of a week for 3 hours.
Also you need to check your drippers frequently as they can become plugged and put out little to no water. Checking if the soil is damp can tell you if the dripper is working.
Bubblers can be useful for large shrubs, such as blueberry bushes, as described in this publication Drip Irrigation for Home Gardens https://extension.colostate.edu/topic-areas/yard-garden/drip-irrigation-home-gardens-4-702/
Using a tuna fish can to measure how much water overhead sprinklers are putting on different areas of your lawn and garden is a common method. Apparently you don't think that would work on dripper output, You do know that the water the blueberry bushes are getting is inadequate. So all I can suggest is increasing the watering time with the system you have now in the hopes of stopping the symptoms of drought.
Thanks for using Ask an Expert.