Few things grow easily here in this red clay in Georgia. I have had some successes and a lot of failures. One of the successes has been the hazelnut bushes. I bought two bare root plants online 5 or 6 years ago (it may have been longer, I really don't remember) along with a lot of other bare root trees, most of which have died since then. For three or four years these were just cute little bushes beside the driveway, growing and spreading nicely. Then one year they produced their catkins for the first time. Hazelnuts produce thin, soft green cone like flowers in spring . Hazelnuts do require cross pollination which is why I bought two of them in the first place. Hazelnuts are self-incompatible which means that like pollens will be incompatible and they cannot pollinate themselves. Hazelnuts are also deciduous and they require some cool weather in winter for them to break dormancy and produce flowers in the spring. However they apparently don't need too cold a winter as we don't usually get below 20 F here in the winter.
I have read that hazelnuts need a well drained soil but I can tell you now that this clay don't exactly drain real well and these two bushes are just thriving here.
Hazelnut bushes grow by underground runners which can be cut and used to propagate more. I have not tried this myself since two bushes has been more than enough.
Here are my hazelnuts forming now. They form in clusters of 4 or more nuts.
Here you can see the hazelnut forming inside.
When these are ripe they will turn brown and the hazelnut will fall out. Usually I pick them once they turn brown but have not yet fallen out.
The hazelnuts I get from these are smaller than what you would get in the stores and are a bit harder to crack since they don't fit in a regular nut cracker. A bag and hammer usually will work just fine however.