Hello, I have a question as to whether or not it is possible to grow productive blueberry plants from seed.

Three summers ago I collected some seeds from a few different varieties of highbush blueberry plants, and have since been able to raise about a dozen or so plants which are currently growing on a sunny hillside in my front yard. They all seem to be very healthy, and are enjoying a good growth spurt this summer. Many of them are now 12 to 18 inches tall, with very healthy foliage. However, I have not been able to determine whether or not I will be able to expect any fruiting from these plants in the future, or if they will instead be sterile. Can anybody advise me on this?If they will not be productive, might I be able to graft to the rootstock of the plants that are currently growing? Thanks in advance for any advice you may be able to offer. Regards,Jeff