Your request for info on growing blueberries was forwarded to me for reply. Last year I researched the subject to give a talk at the HOS All-About Fruit Show. We also grow blueberries in our home orchard.
Varieties: For good pollination and bigger crops, you'll need more than one variety. If you're growing for home use, find varities with different ripening times, early, mid, and late for long production.
Spacing: Blueberries should be planted 4 to 6 feet apart. Closer than that will give you a hedge but not much fruit productiion. Branches are brittle and easily broken if you don't allow enough space to move between bushes for picking and pruning.
Peat moss in planting is essential to establish blueberries. Peat provides them with material like their natural habitat. The Ozark Organic Growers Assoc. recommends as much as 5 to 10 gallons of peat per bush when planting. Be sure peat is moistened before mixing. You can replace half of your soil with peat when mixing material for planting. This would be a good place to add your composted tea leaves, too. The OOGA states that ground pine bark is less desirable than peat, but is much cheaper in certain locations. Go with what you have, but planting time is the only time you can supply blueberries with the peat they prefer. Never use it as mulch because it dries out, sheds water, and won't incorporate into the soil.
Correcting pH levels for blueberries: A recent article (from California) suggests using 2 cups of finely ground (powdered like that used for mixing into sprays) sulfur to be mixed into soil or sprinkled around bushes if needed, but it takes up to a year to give results. Take soil tests for pH in winter or early spring for most accurate readings. Test after one year to see how the pH is doing. You can add sulfur as a top dressing if necessary before adding mulch. Be aware that too much sulfur added too often can affect beneficial soil organisms. The real key to blueberry production is lots of organic material, both in planting and consistently used as mulch.
Site preparation: Sorry, your blueberries need more root space. A blueberry has a mat of fine roots that grow only a foot deep but wide. The trench should be dug about 16 inches deep and 3 feet wide.
Mulch: Blueberries require mulch. After planting spread sawdust mulch (never use cedar--it is toxic to blueberries) out 2 feet around plant to a depth of 3 inches so roots will not grow up into mulch. After the first year increase mulch to a depth of 6 inches and extend to dripline of bush as plant matures. Plants need 1 inch of water per week. Don't let bushes dry out, but don't waterlog them. Blueberries can drown if set without good drainage. That's why they are often planted on mounds in wet soils.
For more information that should be useful to you in Missouri, log on to http://attra.ncat.org/attra-pub/PDF/blueberry.pdf
. Good luck--you'll love having your own blueberries!