I've got a hazel nut tree, but I've also got a squirrel (was two but the cat got one). The existing mature orchard seems to have gone into a 2+ year cycle for some reason (maybe a weather problem) and birds (blackbirds in particular), insect and disease take their toll too. The most reliable producer I've found so far are the two mature walnut trees (although storing the nuts is problematic with the door mice, although the cat dispatched one yesterday).

Any good books on organic orchard keeping BTW?

Nature's great, but when you start competing with it for food, man does it fight back. Oh! And I lost a chestnut tree to the heat two years ago. That old Climate Change can deliver a knock-out blow any time. Whatever people do, diversify as much as is practical would be my tip. Resilience, resilience, resilience!

Fruit production pulls a lot of energy from the ground. You can get back to annual cycles if you thin the fruit set and if you fertilize correctly. Fruit trees need A LOT of lime and they need trace minerals.

On the other hand... alternating year production does limit the insect and virus load.

Thanks will. I've been trimming the grass back from the trees and applying a horse manure mulch, cleaning away the moss etc. The trees are mature and too big, as well as too many, to look after properly. Thining the fruit is not really an option, but the birds seem to be doing a pretty good job at it.

Interesting about the lime, is that to aid mineral release in the soil or for some other reason?

If I can get them back into regular production then it might be worth giving them more time and resources. I've been meaning to study up on them at some time, but it keeps ending up on the back burner.

Burgundy,
i think you live in France, no?
I do too; 6mo/12. In the Cevennes.

In France I've found the "back burner" provides a lot
of extra heat ..... many of my projects smolder there.

We have very old fruit trees which are apparently "fini".
They produce the hardest pears imaginable ....never ripen
tho they get loads of sun.

if you want to talk about Fr. i'm emailable
dadco (at) valley (dot) net
sydney

Be careful with the lime though. It is not appropriate for non-acid lands and should be used with parcimony after an analysis of the land is done. Too large additions release many minerals from the land in the short term but decreases your long term potential.

"Lime make the father rich and ruins the son" as the farmers say.

Hazelnuts- aka Filberts when i was a kid.
They need Boron (B) to set nuts consistently. Solubor is the product that i have but I have no idea the rate. Apply as a foliar application.
Boron is a funny element. The rates are usually in ppm (parts per million)and low(!) Too much is quickly toxic. Beware!