It sounds like the soil might have a high pH. Compost and soil? Doesn't sound very good for blueberries. I grow several blueberry bushes in containers, and the mix is ground pine bark and peat moss. Sounds like a replant might be necessary. I'm sure someone with more experience growing plants in the ground will chime in.

Did you take the pH of the compost/soil? I'm guessing you didn't get the pH low enough, since they like 4.5 to 5.5. They will fare worse in straight clay. Blueberries have very shallow roots too, so they like a deep mulch of wood chips or pine needles, six inches or so.

Agree with above comments. I grow in ground, and I had to mix my native sand with peat, pine bark and compost as well as sulfur about six months ahead to get the pH down.

Blueberries don't like clay at all. They prefer the drainage of sand. The peat and pine bark are acidic and help get the pH down, but I also had to use sulfur and time to get it just right before replanting. I also have several inches of mulch made of pine bark and ground up spruce cones. This helps keep things acidic, and reduces watering frequency as well as keeping roots cool in summer.

You can do everything right, with regard to soil amendments, soil pH, and watering, and still end up with the problems you are seeing. The immediate, emergency solution is to shade the plants from the worst of the mid-day sun, which will lower the metabolic activity in the leaves, and give the roots a chance to catch up. To avoid this problem with blueberry shrubs, plant early in the spring, between March 15 and April 15, and do not use any fertilizer during the first year. This gives the roots more time to develop, before the leaves take off and demand more water than the roots can supply. If you decide to replace the shrubs, fall planting, between September 15 and October 15, should be successful. The days are getting shorter in the fall, which means the leaves are less active, demanding less water, and the roots should be able to get established and stay ahead of the leaves. It is OK to fertilize in the second year. I am having success with fertilizing twice, in mid-March, and in mid-April. After April 15, I concentrate on keeping the shrubs watered, and also on pH.

"shade the plants from the worst of the mid-day sun, which will lower the metabolic activity in the leaves, and give the roots a chance to catch up."

I think this my be more of the case since I planted in mid June. So it seems the leaves need more water and it may be that sprinkling with the hose is not getting down to the roots.

I assume these aren't bare roots and you planted the entire root ball, soil and all from the pot. After one month it probably still has most roots in that potting soil, especially if it's heavy clay around it, roots might just circle in the more porous potting soil.

I think the problem you have, what I see when I get new plants and plant them out in full sun, is that the leaves haven't been grown/developed for that exposure. They were probably in a grow house or nursery shaded by other plants, the leaves adjust to that light level and then boom you stick them in full sun in June. Those leaves burn up and the plant grows new leaves that can handle the full sun.

There was a nice thread on this in this forum or the vegetable gardening forum...I tried but couldn't find it using the search...

Homey_bird: if you constantly need to add iron, then you likely have a pH problem. Adding iron is usually just treating the symptoms, not the cause. What are you using for medium and have you actually tested the pH?

If you are adding iron sulfate as the supplement, it may be the pH drop that's helping.

Melikeeatplants: Good point, although it doesn't look like sunburn. They look like the pH is off. The kicker is that he used soil and compost. Compost usually has a high pH, and we know the soil is clay, which is also not good for blueberries, so there's likely two problems here.

I think he needs to create a properly prepared planting hole with correct pH and drainage. Mixing sand with peat and sulfur in a planting hole would be a good start.

Short of water and/or damaged roots which prevent water uptake. Long-term shortage.

Blueberries need good drainage.
But they also need frequent irrigation to deal with their very *shallow* root systems.
Oh yes, at least 2 inches of mulch also.

RonCz has made the same mistakes that people have made through history with blueberries. He is using what works for most other plants, including mixing compost in clay soil.

If you read through the history of blueberries, people kept treating blueberries the way other plants were treated and had the same results. It was once considered that it was impossible to domesticate blueberries because what worked for other plants didn't work for blueberries until research in the early 20th century in the eastern US discovered the pH, nutrient and drainage requirements of blueberries, and a new industry was born. Sorry I don't remember the exact names and places involved (craft disease), but the history is quite interesting. It's also interesting that even after all these years, people still make those same mistakes with blueberries.

I also made the same mistake when I first planted blueberries, by putting them in my garden bed. I did try to lower the pH by putting sulfur down after the fact, but they never did thrive until I prepared a bed specifically for them with the proper conditions. They have thrived since.