What's wrong with my walnuts?

[Lizzie]

I have a lovely walnut tree, which was loaded with nuts this summer. I have been picking them as they fall and drying them in the greenhouse. When I crack them for use, I find they have either shrivelled completely or have grown some mould (botrytus?). Sometimes, the nuts have turned a brilliant yellow. Is it safe for me to eat any of the nuts, or should I throw them away? And - this is the fourth year the tree has had this problem, although the crop this year is by far the biggest. Is it due to the wet weather we have had in South Wales during July and August each year since 2007?

[Lucy Robyn]

Have you fed the tree, I think walnuts are hungrey feeders. I've only got 4 nuts from mine (squirrel had the rest) and haven't cracked them yet.

[oldjerry]

Not sure how I'd feed a walnut tree,I've found them very up and down in terms of cropping especially north of the home counties(though apparently there are newer more reliable and quicker fruiting varieties now available).In Italy at the outlaws place they always fruit heavily,but there too you often get manky ones amongst the gooduns,theyve never made me seriously ill,if they dont taste right just spit them out.All this can be avoided if you pick them immature in say May/June,and pickle them whole,a true delicacy.

[Millymollymandy]

Getting them dry is key here - this is the first year we've had really wet weather as they were starting to fall and if there's no sunshine it is really hard to dry them out. Some of mine were starting to go mouldy on the outside but thankfully we've had a week of sun and they are OK now, so I pray they are OK inside!

There usually are some that are already mouldy or just black and shrivelled even before they fall, and I have some of those yellow ones too. Don't eat the ones that are mouldy inside the shell but there's nothing wrong with the yellow ones in my opinion. Taste a bit and see - if it tastes mouldy don't eat.

If all your nuts are like this I don't know the answer other than they might not be drying out quick enough (though I don't know what causes the yellow ones).

[Lizzie]

Thanks to those who replied. I am still picking walnuts and there are loads more still up in the tree. Have been cracking the ones just picked - and they are lovely. The last time I had decent walnuts that kept was 2006, so perhaps it is the weather. Are walnuts native to Wales? I doubt it.

[welshmum]

ok, I am going to ask something completely stupid now, so please accept my apologies in advance! The tree that I am posative that is a walnut tree, white variety, is still laden with walnuts. They are still sticky to pick but the nutty bit inside seems more developed than previous. How much like teh shelled walnuts that you buy from the supermarkets will they look on the tree? How do I know if they are ready to pick?

[Millymollymandy]

On the tree they have a green outer casing so they don't look anything like the inner nut that you are used to seeing/buying. When they are ripe the outer casing starts to split open and then the nut drops out onto the ground. That's when they are ready to pick - they are generally collected from the ground, not the tree. If you google you will see plenty of images which will confirm for you whether it is a walnut or not and will show you the outer casing.

and to Lizzie - often the first ones to fall are the undeveloped/sickly ones. Glad you are getting good nuts now!