Over the years we’ve planted quite a few chestnuts. In The North Florida Food Forest Project, we planted a paid of Dunstan Chestnuts back in the 2011-2013 range. It would be interesting to see how they’re doing today. When we visited in 2019 they really hadn’t grown a lot, but we hadn’t been there tending and feeding and mulching since 2016.
At our new property I planted a good-sized Dunstan chestnut (purchased at Walmart of all places). I planted another smaller one in the back of the house.
The larger one bloomed for the first time in 2025 and gave us a couple of empty nut husks. It might be because it’s young, or it could be a pollination issue since the other tree is far away with a building in between.
We probably need to hunt down another Dunstan to plant out front so we can make sure it’s pollinated, in case that tree out back isn’t enough.
The goal is to have seeds we can plant in our nursery. I have maybe eight or so Chinese chestnuts planted around the food forest and Grocery Row Gardens, but having more Dunstan-type resistant trees with American genes would be a plus.
With some trees we can simple air-layer, graft, or start cuttings.
But it’s hard to propagate chestnut.
Consider these pdf excerpts from the Department of Biology, Faculty of Sciences, University Santiago de Compositela, Spain, por ejemplo:
INTRODUCTION
The selection of chestnuts (Castanea spp.) which are resistant to blight or ink diseases, and the necessity of propagating them asexually, created one of the most complicated forestry problems of recent decades and attracted the attention of many people from both management and scientific fields.
GRAFTING
Grafting in chestnut has met with only limited success (Turner, 1964; Shafer, 1966). One of the main causes of failure is incompatibility between stock and scion. Reasons for this are many: lack of winter hardiness of stock-scion, chestnut blight in the graft union, poor grafting techniques, and the use of different strains or species of chestnut for stock and scion. There is probably no one cause of incompatibilty in this genus (McKay and Jaynes, 1969).
Nursery Grafting
The most satisfactory nursery technique is splice grafting, although whip grafting is used by some workers. Woodroof (1967) recommends that the root stock be allowed to leaf out fully before grafting dormant scions. The results of an entire season may be lost if grafting is done too early because buds may be killed by a late spring frost. Kajiura (1955) reported that grafting chestnut was considered difficult, and only 40-50% success could be obtained. After further studies, however, he showed that 80-90% success could be expected in Japan if the following conditions were observed: scions should be collected by the middle of February (late winter) and stored below 5°C, preferably at 2-3°C; grafting should be done about mid-April (spring) when stock has sprouted and can be peeled.
Topworking
The veneer crown graft has been reported as quite successful as long as sufficient single branches are left on the stocks to draw the sap (Graves, 1956). The main branches of the root stock tree are sawn off some distance above a fork, and one or more scions are inserted in the cut branches (Nienstaedt and Graves, 1955; Graves, 1956).
Budding
Chestnut budding has generally met with failure for reasons that are not fully understood (Jaynes, 1969). This technique is not widely practised because the wood is fluted or grooved, and the cambium of the bud and stock do not join uniformly (Woodroof, 1967). To improve the percentage of takes Hartmann and Kester (1964) recommended inverting the buds.
Nurse Nut Grafting
This technique was developed by Moore (1963), who thought that seed cotyledons would supply some kind of rooting substance which would induce root formation on the scion grafted onto the nut. However, roots are not formed on the scion, but from the differentiation zone of the root of the seedling. While Moore’s idea served to develop a series of new grafting methods (Jaynes, 1964; Park, 1968; Beck, 1970), it has not itself proved to be a commercially successful method (Cummings, 1970).
Nurse Seed Grafting
This technique was developed by Jaynes (1964) as a modification of the method proposed by Moore (1963). Essentially it was similar except that nut stocks were used shortly after germination and before the epicotyl had emerged. Good roots were generally established on 60-80% of the grafts within 21 days after grafting. But heavy losses of grafts occurred during the hardening period. Factors responsible for the losses include transplanting shock from disturbing the roots, too sharp a drop in humidity, or incompatibility between stock and scion. As the nut is more than a nurse for the grafted scion Jaynes and Messner (1967) proposed the name “nut grafting” for the method.
Juvenile Tissue Grafting
Park (1967) reported good success in utilising as scion material the new elongating shoot from either germinated seeds or mature trees, and grafting these onto young seedlings. The principal factor affecting the success of grafting was the degree of development of elongating shoot of both stock and scion. The best grafting stock was when the seedling came to bear about four leaves, and the best grafting scion when the shoot came to bear about four ordinary leaves. It was claimed that juvenile tissue grafting was more successful than nurse seed grafting. In the exposed field bed the optimum depth of planting of grafted plants was 7-8 cm giving a survival percentage of 80% (Park, 1968).
Inverted Radicle Grafting
Inverted radicle grafting is a modification of the nut grafting method (Beck, 1970). The root is cut off 3-5 cm below the hypocotyl, inverted and split down the middle for about 1.5 cm to receive the scion. It is an easy graft; the cotyledons are at the opposite end away from the area when the graft is made and there is no danger of the cotyledons being cut off. Anatomical studies carried out by Park (1969) showed that the meristematic activity of the embryonic pith of inverted radicle stock was higher than that of the hypocotyl, making union easier. Inverted radicle grafting was more successful than modified nurse seed grafting. Jaynes and Messner (1967) have pointed out that none of the seed and seedling grafting techniques avoids the general problem of incompatibility, and that transplanting during the growing season as required by many of the methods may diminish survival.
LAYERING
Air-Layering
This technique was unsuccessfully tried by Urquijo (1946), Graves and Nienstaedt (1953), and Nienstaedt and Graves (1955). Shelton (1969) air-layered walnut and this method may be applicable to chestnut. In walnut, auxins assist root formation in airlayers (Vieitez, 1955a). Shreve and Miles (1972) induced root formation in shoots of Castanea mollissima treated with 5,000 ppm indole-butyric acid (IBA). Root formation depended largely on the type of twig treated, one-year shoots being the most successful. Vieitez (1961, 1963 and unpublished) studied the effect of etiolation of shoots on root formation, in order to acquire more information about the rootability of chestnut. By the end of May the basal zones of 75 shoots produced from one clone, usually by stooling, were treated with 4mg IBA + 4mg naphthalene-acetic acid (NAA) per g of vaseline and were then wrapped over 15 cm of the shoots with aluminium foil. The treatment was repeated at the medium and top zones of the shoots at one month intervals. At the basal zones, shoots rooted 87%; medium zones 100% and top zones 79% (Figs. 1, 2). The decreased percentage of rooting at the tops is explainable as the twigs were very soft and showed necrotic areas following treatment. Control shoots rooted 41 % but only at the basal zone of wrapped shoots…
Alright, that’s enough. You get the idea.
This is why we are planting lots of trees that will give us lots of nuts that we can grow into a lot more trees for our plant nursery.
