I have a Casina and a Barcelona filbert, both planted in 2003. I also have some older trees that are from seeds that were in my yard when I bouhgt the place. I haven't gotten any nuts from any of them yet. The Casina is in bloom in early January and the Barcelona blooms after the Casina is done. This year I hand pollinated the Casina blooms with catkins I picked off the seedling trees that were in bloom at the same time.
We have 10 filberts; 1 Halls Giant, 2 Tonda de Giffone, and 7 Ennis. All but 2 of the Ennis are 8 years old. We get good nut set; the trick is beating the Stellar Jays to the nuts. They know which shell have nuts, and pick them before they're ripe! This year we may net some of the trees (the Ennis) to see if we can get more of the harvest. If you live in an area that does not have Eastern Filbert Blight, I highly recommend Ennis as one of your varieties. The nuts are large, good quality, and very few blanks. Ennis is very susceptible to blight, so I know it is no longer recommended south of Longview, WA, or in Oregon.
Years ago I tried an Ennis and a Barcelona Filbert tree. After about 5 years of nothing - I gave one away and dropped a fir tree on the other.
Willamette Mission State Park (on the Willamette River) has a large once commercial filbert orchard. One fall day I and my Homeschooled kids made a trip to 'harvest them.' Before we picked up too many nuts, I decided to test a few. They were large and beautiful, Barcelona I presumed. But every single nut was empty! I think it's Filbert Husk worm ... and I've been told they require a spray program to combat them ~
The best we can do around here are wild Hazel nuts, and as mentioned above, attempt to beat the Stellar Jays to them - which we can't 
There are a couple of neighboring Filbert orchards we occasionally wonder into at 'that' time of the year ... the nuts are great at that pre-dried stage. But considering the obstacles, I no longer recommend Filbert yard trees. They sound like a great source of protein, but in practicality - they were duds. If you decide to give them a try, be careful to match pollinating varieties.
As far as looks, the catkins in February were pretty, but you either prune them to a single trunk like a 'tree,' or allow them to sprout into a 'clump' like figs do. We liked the tree look, but perhaps production-wise ... that wasn't the best method?
Viron, I think the tree method is better for production. And you are right that the jays can make the effort frustrating. But like all "homegrown" products, filberts are worth the effort if you have the room. Because they are wind pollinated, it is recommended that you plant at least 3 varieties for good nut set (at least that is what our long ago research said), and they grow into 15' trees. I find them quite attractive, both in the winter, with their catkins promising spring, and in leaf- very textural round leaves.
Terry, I'd thought my long ago research said the two I'd planted were good to pollinate each other? I also wondered if the 'Wild hazel nuts' that border our orchard wouldn't have provided pollination too? Once a meter-reader for the City of Milwaukie (Ore.), I knew where all the best 'food' producing trees were ... in fact, I've got grafts of several growing out here now. I remember a family that had planted about 5 filbert 'trees' - they actually became 'clumps' - along the front of their yard. All of three years that I pocketed those nuts, they were great! It appeared as if they were prospering with neglect! 'Those' were actually the inspiration for eventually planting mine - it looked as though anyone could do it...
I wonder if Eastern Filbert Blight's taking out home orchard Filbert trees here in the Willamette (more specifically to me the Tualatin) Valley? It was a major concern when we relocated and planted our Filberts out here over 20 years ago. I try not to discourage anyone willing to plant anything productive, and with filberts, you can deal with most of their short comings at will, I just lost my patients; and now we simply enjoy looking at the 'Wild ones.' We do have a beautiful "Red Filbert," given to us as a gift. I'm never on top of the situation enough to beat the birds to them either, but supposedly their meat is red! - as are their leaves 
One other venture of mine was to procure some neighboring Filbert 'wood' and graft it onto some of our plentiful wild Hazel (brush) shoots. They were all cleft grafts, carefully done - with some prior experience on my part - but none of them took... I was told later 'why' - something about needing warmth ... but I forget. So enjoy / protect yours 
Idyllwild
jafar
Marsha H
Viron
John S
1 Guest(s)