Superior Blueberry Bush Nutrition or Water Deficiency

Question: My blueberry bush shows signs of stress and nutrition deficiency. I got it a month ago from Bachmans and potted in a 16” gallon container with a mix of 1/3 peat moss, 1/3 potting soil, 1/3 pep soil conditioner and some Holly-tone fertilizer.  I measured my Ph at 5.7. I water every 3 days about 1 gallon. I reported today in a 20” container in 1/2 peat moss and 1/2 pine fines and mulched with pine bark nuggets and Holly-tone. I measured my Ph at 5.0. I will let it be to see if it does better, but welcome any feedback about I am doing wrong.

responder: MaryKay, Master Gardener, Tree Care Advisor Replied June 11, 2023, 9:12 AM EDT
response: Your leaves are showing signs of nutrient deficiency-yellowing leaves with green veins.  Growing blueberries in small containers is very challenging.  Nutrients wash through containers quickly due to need for  frequent watering.  Potting soil for acid loving plants is a must.  The website below gives additional suggestions.  The current hot days require daily watering of containerized plants.  I water mine twice a day when the temp is above 80-85. Loose potting mixes drain even faster than soil carrying nutrients with them. The brown edges of leaves may be scorch.  While your pot is adequate, a larger pot may also help retain more water and nutrients and a lower pH.   https://www.thespruce.com/growing-blueberries-in-containers-848170

responder: The Question Asker Replied June 11, 2023, 3:02 PM EDT
response: Thank you MaryTwo follow up questions about watering and nutrition that I could not figure out online.1. I am going to increase watering. When you water daily, do you do a deep soak and wait for the water to come thru the pot holes?For my 20” pot, I figured out that 2” inch of water per week equals 3 gallons. I am trying to figure the daily intake.2. For nutrients, should I use liquid fertilizer like Miracid, I read somewhere to do so every 14 days from mid-May to mid-July. Since I use Holly-tone at the beginning of the season, I did not know if it is needed. The site you recommended mentioned a monthly dose of fertilizer. What should I do?Thank you muchFrederic Sent from my iPhone On Jun 11, 2023, at 8:12 AM, Ask Extension <<personal data hidden>> wrote:﻿

responder: MaryKay, Master Gardener, Tree Care Advisor Replied June 11, 2023, 6:11 PM EDT
response: Yes, water until the water comes out the bottom drainage hole.  Do not let the plants sit in water. Water needs can vary due to heat, wind and soil composition. Check the top 6 inches of soil with your finger. That will give a better idea of when to water.    Holly tone is a slow release fertilizer which is why it is used only twice a year.  And it does not take into account the container grown  berries where the fertilizer can wash out faster. If the plants are in the ground the fertilizer is not as mobile as in a container.  The Miracid label does not include blueberries.  It may be too strong as a regular fertilizer because it is not slow release. If you use such an acid fertilizer that is not slow release, be aware that you will need smaller doses more frequently. Use a diluted version first and look for plant response. The above website recommends dividing the slow release fertilizer for a monthly dose for container blueberries.  This may require some experimentation.  Always use a more dilute form of fertilizer in containers and look for plant response.  Too much will burn plants.  More to the point keep testing the pH because that may be the problem.  You may need to adjust the soil composition rather than the fertilizer.   no amount of fertilizer will makeup for a soil that is not acidic enough.  The following website is for blueberries grown in the ground.  But it does explain the soil and fertilizer needs and may be helpful.  https://extension.umn.edu/fruit/growing-blueberries-home-garden