2 chestnuts in one hole?

Reading this forum here:

http://www.daleysfruit.com.au/forum/chestnuts/

The advice given is not to plant 2 chestnuts in one hole.  On the other hand, in the online book West Coast Food Forestry it is said that it can be done.

The chestnut is a large tree, my thinking would be that planting a male and female in a single hole would have the effect of stunting them a bit which would essentially dwarf the trees.  Could be good for an urban setting where a more manageable size is better.

Anyone wish to share their experience or speculation?

I've heard of people planting two seeds in the same hole before and seem to remember that they do it in order to improve the chances of a healthy tree taking root. The weaker of the two (assuming both start growing) is simply thinned out or possibly transplanted elsewhere.

That is one way to do it but my idea is more along the lines of what people often do with european fruit trees.  E.g. plant 2 apples types in one hole for cross pollination.  In this case it would be male and female chestnuts for pollination.  So I'd definitely want both to survive.

There is a method called "Backyard Orchard Culture" whos intent is to keep trees small and fit the maximum number possible in the smallest space. To this effect fruit trees are planted 2, 3 or even 4 to an area. Its not usually in the same hole but can be. I space mine about 3 feet apart in a square shape. It works but requires regular pruning. Trees should survive fine.

FWIW, as two were recommended for cross pollination, I planted two chestnut varieties in one hole several years ago.  And now one is much larger and fruiting, while the other is smaller, and providing the alternate pollination, I'm assuming.  Seems to be working fine, as I was only looking for optimal production from one tree.

Thanks Nancy, that's the sort of info I was seeking.  Anyone else have experience to share about doing this?

@Nancy - I was thinking of chestnuts, but am in a frost pocket and have been worrying that I wouldn't get any production due to flowers getting zapped.  What variety in what kind of site to you have?  Have you been getting nut set?

It's been so long, I'd have to guess at variety, but I got them at Home Depot, of all places, so they must cpmmon - seem to remember 'chinese' and/or 'colossal' in the name.    And, yes, they started bearing their spiky fruit a couple of years ago.  Trunk diameter on largest is about 8" and 3" on smaller, which is about 1/4 of the size of the other, overall.  Biggest is about 15-20 ft tall.  Their canopies are intermingled.

My main goal was a visual screen, which is working well, so they are not in particularly advantageous position.  No morning sun, an on and off afternoon, at the top of a 12" ravine, surrounded by large apple and willow.  We are close to the Sound, so temperate climate, but we got last year's freezing snaps, and that big freeze in..... '08'?  (No electricity for 8 days

These trees are definitely not delicate, and the squirrels are fat.  (Oh, btw, there is an ancient, giant chestnut tree in downtown Tacoma, that Asians have harvested for years, across the street from King's Books.)

I don't think chestnuts are like, say ginko, where you have male/female trees, are they?

I think nearly all subtypes of chesnuts require a pollenizer, but each tree can in turn be pollinated and produce nuts of it's own.

You're right KB, thanks for pointing that out.  Yes, they are monoecious, so my comment about male and female plants was off track.  What I should have said was that 2 are needed for pollination as they are self sterile.

I'm planning on doing something similar, in the hope that they'll remain on the small side. I probably won't plant in the same hole exactly but very close, perhaps a metre apart. I'll be sowing seed and doubt I'll around to see them reach their full height.

I have also heard of two in one hole, but I wondered since chestnuts are frequently coppiced, if two poles are growing back on a stump that was harvested a year or two before someone might have just assumed it was two in one hole.
A good web site for information about chestnuts is http://www.badgersett.com, they are in Minnesota so chestnuts are likely pretty frost resistent.