Hi esyke623. You are on the right track. Your soil mix sounds good and you are aware of the drainage issues you have which will be your biggest challenge. Planting them in an amended hole is a good idea. You are also aware enough to know to plant wide. If you think there is any chance of the roots getting saturated, consider digging deeper and putting gravel and a perforated pipe (or similar) leading downhill to the surface to drain excess water at the bottom of the hole. Blueberries absolutely will not tolerate saturated roots. If your soil does get saturated and you aren't willing to put in some kind of drainage, then you may be better off with a raised bed or grow in containers.

If you do plant in ground, put several inches of acidic mulch on top to reduce the need to water.

There are a couple of variables as far as adding acid to the water. If you use rainwater, don't worry about it. If you use hard tap water, more then likely you'll need to acidify your water. If you soil is lower then optimal pH, you may be able to water with tap water alone. You'll need a pH meter to figure your best plan. In clay soil, you may have to rarely water at all.

Blueberries are all about intitial preparation. If you get the soil conditions right, they will almost look after themselves, as they require very little nutrient, and have very few pests. Once established you may not need to do much more then pruning, weeding and harvesting.

Your best bet is to go with either pots or a raised bed on top of the clay. You will have problems if you plant in clay regardless of amendments. I have clay in my yard and made raised beds with pine 12in tall, 4ftx4ft wide with weed blocker on the bottom. Fill the bed with 2/3 pinebark mulch and split the last 1/3 with sphagnum peat moss and sand or perilite. Find some mycorrhizal fungi either at a local nursery or online and use as directed. Add a 1/4 cup of sulfer and mix everything up and plant. This has worked great for me so far. I use the same mix for pots also but of course you will need to reduce the amount of sulfer. 1tbls per 7 gallons seems about right for me.

You really need to know the ph of the water you are using aswell. With only a couple plants, your best bet is to collect rain water from your gutter. You will not have to acidify rain water. If using tap or well water consider using Sulfuric acid to bring the ph of the water down to 5 or you will raise the ph of the soil quickly.

One thing Im trying as a experiment is to not add any sulfer to my potting medium on one of my plants. Instead I acidify a barrel of rain water to ph 4.8 (which doesnt take much, only 5mL for a 55 gallon drum)and use that to water the plant. So far so good. IMO it should take the guess work out of maintaining the potting medium ph. Only time will tell.

Dang Capoman, we sound like a broken record. We were replying at the same time. One thing he mentioned that I didnt was a good layer of mulch is a must. A 3 to 6 inch layer of pine bark mulch is the way to go.

Thank you both so much for the suggestions! So about planting on a hill vs. flat-- anything to recommend about that, if soil conditions are good? Do they prefer the drainage of a hill, or would that dry them out too much?

I wouldn't dig holes in the clay and fill them as they will oversaturate and kill the plants. Raised bed on top of the clay, or 4' rows with drainage at the esides, lots of mulch. Slope towards drainage. That's how the commercial approach in Mi. deals with clay. Have fun and good luck

Although I mentioned how to do the drainage on a hill if you want to be in ground, it is complicated to do, and I'll concur that raised beds are your simplest bet. Also, I think blueboy's raised bed mix is just about perfect, and also affordable.

To answer your question, if the soil conditions are good, drainage of a hill would be preferred. I should caution though that a good soil condition for blueberries would mean that roots NEVER get saturated. That is usually reserved for sand, not clay.

About watering, I'm not convinced using rainwater or treated water is necessary. The ph of my well water is above 7 and I water my blues with it every other day without any problems.

The trick is to use ammonium sulf, sulfur, and bark/peat to control the ph. My recent soil tests showed my ph was actually almost "too low" despite watering straight out of the well with untreated water for the last two years. We have some scorching hot summers here too, I have to water them heavy and frequent from late June through mid October.

As for planting, follow the advice of those suggesting raised beds for the best results. If you don't want to use raise beds, dig a hole about 3' across and 15 inches or so deep. The roots on my plants are mostly pretty shallow and wide. Use a mix of mostly peat, a bit of potting soil, and some pine bark if you have it. You can then mulch with pine needles, pine bark, and peat each year to help maintain soil moisture.

RM

Agree Riverman. Rainwater is best, but as I mentioned in a previous post, if your soil pH is a bit on the low side, you may not have to pH your water. I am in a similar situation as you as my current pH is about 4-4.5 which is a bit low. I use rainwater most of the time, but I don't pH my water either, knowing this. My tapwater pH is just over 7. In any case, high pH water is better then allowing plants to go dry, so if you run out of vinegar or sulfuric acid during a drought, water anyway.

I would say though you have to be real careful if your water is extremely hard and/or has a very high pH. Many tap waters are over 8 and I think that's getting excessive.

The plants will tell you if you aren't getting it right. pH issues are very obvious in blueberries.

I would not be setting out blueberry transplants at this time of year. I would wait until September 15, or possibly October 1, to dig and plant. The potted shrubs can be kept in a somewhat protected location in the interim, where they get full sun for several hours, and partial shade for the remainder of the day. Blueberry root systems need some time to develop, and if there is too much growth above ground, too soon, the roots will not be able to keep up with the leaves, leading to dead leaves.