Fruit and Nut

Heartnuts (Juglans ailantifolia var. cordiformis) are a relative of the walnut native to Japan but were introduced into North America during the nineteenth century. They are relatively uncommon in Europe but are hardier and more vigorous than walnuts, less prone to disease and more tolerant of wet climates. They have the potential to do very well in Ireland. Young trees on our trial site near Westport produced their first crop at five years.

Heartnuts have a reputation for being hard to shell, but all the cultivars offered here have improved shelling capability. The trees offered are not grown from nut but are propagated vegetively by grafting fruiting scions of known cultivars onto seedling rootstocks. Most of the cultivars offered here originate in Canada or the northern parts of United States.

Unlike trees raised from nut, which are unreliable in terms of nut production and quality, and take many years to reach nut bearing age, grafted trees always come true to form and begin cropping at a young age. The trees are generally not self-fertile so more than one cultivar should be planted. Heartnuts flower early to mid May and are sensitive to frost so should not be planted anywhere prone to late spring frosts. The most successful sites will be those where frost is rarely experienced after the beginning of May.

Heartnuts grow into big trees so should be spaced at 10-12 meters.

Our heartnuts

Our trees are heat-grafted under contract, shipped to us immediately after the callusing process is completed, then grown on at the nursery in fully organic conditions in raised beds or pots. The freshly grafted trees are supplied to us at about 25-30cm high, and do not develop much the first year. The typical tree will reach about 40-60cm the first year, however ones with vigorous roots may grow larger. In the second year development is much faster and by the end of the second year the trees will have strong leaders and a thick mat of hairy roots. We are the only nursery in Ireland raising heartnuts and pride ourselves on the high quality of our trees. Nut production can begin as early as year 4, though more typically it is year 7 or 8.

Supply

The new consignment of grafted plants was received from the grower in early June. We are now containerising all our heartnut trees. Initially the trees were grown in 5L pots (June-August) then during August the trees were potted up into 7.5 and 12L pots. Over the dormant season, the stronger trees will be repotted again into 20L pots. This is a one-off batch as we're not taking any additional trees in 2021/22 so once these trees are sold then we won't have more available until 2022/23.

Heartnut trees are always in great demand so early ordering is advised.

Cultivars

Adelphia
New US variety from Rutgers' research farm of the same name (NJ). Large nut, ripens later than CW1 and Imshu. Excellent cracking quality. Protandrous (male flowers before female). Available 2020/21

Campbell CW1
Canadian variety. Medium to large nut, top performer, nuts tend to come out in halves. Vigorous grower with some resistance to late frosts. Protogynous (female flower opens before male: needs pollinator) Available 2020/21

Campbell CW3
Canadian variety. Medium sized nut, heavy producer, later cropping than CW1. Protandrous (male flowers before female). Pollinator for CW1 and Imshu. Available 2020/21

Campbell CW4
Canadian variety. Medium sized nut, moderate producer, later cropping than CW1. More compact in growth.Protogynous (female flower opens before male: needs pollinator). Not available 2020/21

Fodermaier
US variety (NY). Large nut with good cracking ability. Heavy cropper, widely planted in North America. Later ripening than the Campbell nuts. Protandrous (male flowers before female). Available 2020/21

Grimo Manchurian
Canadian variety. Medium sized nut, compact tree, possibly more suitable for smaller gardens. Very winter hardy but a little susceptible to late spring frosts. Not available 2020/21

Imshu
Bred from Schubert and unnamed Korean seedling . Small to medium nut, moderate to heavy producer, usually cracks out whole. Excellent cracking quality. Some resistance to late frosts. Protogynous (female flower opens before male: needs pollinator).Very vigorous grower (the most vigorous of the selection offered here). Available 2020/21

Kalmar
Swedish variety developed from mature tree found growing in Eastern Sweden. Vigorous tree. Winter hardy but a little susceptible to late spring frosts. Available 2020/21

Schubert
US variety. Parent of Imshu. Medium sized nut, moderate producer. Vigorous tree, good resistance to late frosts. Not available 2020/21

Simcoe
Large nut, good cracker, productive. Protandrous (male flowers before female). Not available 2020/21

Stealth
Medium sized nut, easy cracker. Protandrous (male flowers before female). Not available 2020/21

Heartnut seedlings

Two year old plants raised at our own nursery from selected seed from Ontario province, Canada. Unlike the named cultivars of Juglans ailantifolia var. cordiformis, these seed-grown trees are very unlikely to produce reliable crops of nuts. Vigorous and strong, they will grow into fine large specimen trees suitable for timber production. The trees may also be used for rootstock for grafting purposes.

50-80cm €9.50 ea

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