I’m establishing a long-term homestead orchard / food-forest style planting in central Wisconsin, roughly Zone 5a. My goal is productive trees, but not a commercial orchard. I want to avoid heavy annual pruning, future culling/removing trees, or constant canopy-control work.
I’m now second-guessing whether I spaced my trees too widely.
I planted chestnuts at around 40 ft apart, mostly grafted chestnuts with some seedlings. My concern is that I stretched some to 40 ft when 30ft or 35 ft might have been enough.
My goal with chestnuts is permanent, full-crown trees with good sunlight, nut production, and no future thinning/culling. But I also don’t want to waste limited good orchard space.
So I’m wondering: for chestnuts in Zone 5a,Is 40 ft unnecessarily conservative?
Overall: I’m not trying to maximize yield per acre like a commercial orchard, but I do care about using space well and fitting a good diversity of cultivars/species.
Plus, I figure with the space in-between the trees, I can plant many other shrubs and various other plants to fill in the gaps.
Do you have chestnuts in that area? I have one nearby that is 20 feet tall by 15’ wide. It is 20 years old. There are many factors. @Fusion_power knows a good amount about named varities and can offer more help I think.
40 feet sounds generous but honestly for a low-maintenance homestead approach I think you’ll be happy with it long term. Chestnuts get wide when they’re not competing for light and that spreading canopy is what gives you the best nut production. At 30 feet you’d be pruning to keep them off each other within 15 years. The only downside to wider spacing is pollination distance but at 40 feet you’re still well within wind pollination range for chestnuts, they’ll find each other fine.
It will take a long time for them to fill that, but they might, they can live 250 years! Actually I’m not sure about grafted ones, but the seedlings can.
What would I recommend? Seabuckthorn and hazelnut between them! Or something else, perhaps you can make rows with the trees and add 3 or more things between them especially something nitrogen fixing closer to your chestnuts, Sea Berry (aka seabuckthorn berry), Goumi, Siberian Pea Shrub, Autumn olive, and hazelnuts half way in between the hazelnuts will always stay to a shrubby size and not compete for sun, and you’ll get nuts off them sooner than your chestnuts, probably. Semidwarf apple trees, or Asian pear trees half way in between would be great too and wouldn’t interfere.
Alternatively you could plant entire rows of berries between your trees, raspberries, or blackberries or something like that.
This is a European Japanese chestnut hybrid that my parents planted in 5b almost 30 years ago. It was probably nearly completely neglected and planted without fertilization, on an old unproductive corn field full of rocks, but it’s finally doing well.
And this is a Dunstan that I planted about 14 years ago without any care other than a little water, a tree tube, and a fungal dip before planting. It was a three trunked tree and for various reasons eventually was cut back to one, so it lost a lot of growth that way too.
All those in the orange cages are Chinese hybrid chestnut seedlings, possibly some pure Chinese and one Japanese way way back, that’s the North side of the new orchard, so it got the big trees, 18 foot spacing in square rows.
Trunk to trunk spacing of 35 feet. They will eventually have to be thinned if you want to maintain production. The most they need as very large trees is about 60 feet tree to tree. If we were talking about American Chestnut which can become very large forest trees, they would need more room. But we can’t grow native American Chestnut any more due to disease.
I think you are pretty good at 40’ it will be a long time before they encroach on each other.
It all depends on your timeline and space. Trees tend to use the space given.
Probably takes a long time to close the gaps between them. If your young it may make a difference, but I’ll be fertilizer before they are into each other at 40’
My 2 are at 15’ centers and about 3” in diameter. I have to dig them and space them this next spring taking the future into consideration. They are more than ok now, but I have to move them when small enough to handle.
My understanding is there can be pollen incompatibility between Chinese hybrids and Japanese-European hybrids such that edible nuts don’t develop. So some sites suggest planting clusters of only one type or the other type.
Then I was told for small plantings (e.g. 3 or 4 trees), be aware the pollen-sterile hybrids make seedlings that are approximately 50% pollen-sterile, so with only 3 trees after one dies or gets rubbed by a deer, I might not have viable pollen.
I guess the original poster can control pollination using grafts. They are grafting on seedling rootstock that doesn’t imbue special properties like size control or diseases resistance. Since it’s just seedling rootstock, maybe this is a time when burying the graft union 4" to hope the scion sprouts its own roots. I think the University of Minnesota or Wisconsin in a lecture said delayed graft failure (which can affect chestnuts) happens as far south as Missouri.
If you’re talking about the thing they say about the shriveled nuts from Colossal Chestnut and blaming that on Chinese pollen, that’s a myth, it’s just a downside to Colossal Chestnut, that happens. If you’re saying that Chinese chestnuts won’t pollinate European Japanese hybrids, that’s probably correct, but Chinese hybrids might. But I’m not worried about that I have a Dunstan, which actually had a lot of European genes, and I have a Japanese chestnut too, so they’ll pollinate it.
Now “pollen sterile” is another chestnuts myth, or perhaps just a misnomer. Pollen-sterile seedlings are trees that produce perfectly viable pollen, but they’re not able to pollinate their siblings or mother tree because their genetics are too similar and it’s rejected just as the trees would reject their own pollen. You can plant two different types of pollen sterile Chestnuts near each other and they’ll pollinate each other and each other’s seedlings just fine.
This is “self-incompatible”, not “pollen-sterile”.
While this is a complex subject, I can shed some light on what it means to be self-incompatible using tomato genetics. Domestic tomatoes do NOT have a self-incompatible gene, but several cross-compatible wild relatives do. The gene involved is usually designated “s” and is part of the nuclear genome. When present, it detects pollen that carries the same gene and rejects it.
Pollen sterile is usually reserved for a plant that either does not produce pollen or produces pollen that is incapable of fertilizing a female flower. While I don’t know yay or nay regarding chestnut, pollen sterility is so common in the plant world that I would be surprised if all chestnuts manage to avoid it.
