The more varieties you have closed to one another, the more blueberries you will have on your bushes. I have a total of 18 blueberry bushes planted in my food forest. I believe I have six varieties. The funny thing is if you purchase blueberries from the store, they pretty much all taste alike. However, the ones I grow, have very distinctive difference in flavor, sweetness, and size. Love it when I have the excuse to purchase more plants :)