they are 3 5 yr old and 1 7 yr old hybrid hazels from Arbor Day/ Badgersett joint breeding effort to improve hardiness and nut size. 2 of the 4 have large nut size. the other 2 are smaller but still very productive. all branches were on the ground from the nut load. they produced last year for the 1st time. these are hybrid American hazels. the biggest ones are about the same size as the euros. how old are your bushes? do you have suitable pollinators?
Mine are all seedlings of supposed EFB resistant varieties. They were planted year after year with the oldest being 4 years. I’ve got about 30 of them scattered around. After I saw that video of Hazels cropping in near total shade, I suddenly had plenty more space for Hazels. They grow a lot slower in shade though. I still have plenty in full sun. I’ve been turning my focus to nuts. They stay good for years and you don’t have to deal with them immediately.
and they just grow with 0 input. i did fertilize them last spring for the 1st time. besides that i just mulch them every spring. they dont like to compete with grass around their roots. im ripping out a patch of raspberries and replacing with hazels next spring. less work.