Heartnuts are also known as the Japanese walnut (Juglans ailantifolia var. cordiformis) although they are really a sport of the normal oval shaped nuts. The cultivated varieties have a heart shaped nut that cracks open on the edge and have been selected for flavour, cracking quality and productivity.
Heartnuts are considered hardier (for winter cold) than English walnuts (Juglans regia) and are more resistant to walnut blight, they do however all come into leaf in April to very early May so are suspectible to later spring frosts, they should be considered similar to early/mid season English walnuts. Even though they are often partly self-fertile it’s better to plant two or more cultivars to help pollinisation. They need full sun and well-drained soil and in the first few years concentrate on putting down a long taproot.
During winter it is worth using fleece to protect the grafted area of the tree for the first few years. Trees can grow to 10-15 m in height and width so space at 10-12m.
| Variety | Description | Availability | |
|---|---|---|---|
| Adelphia | US variety from Rutgers' research farm. Large love heart shaped nut, ripens later than CW1 and Imshu. Excellent cracking quality. Protandrous (male flowers before female) | None | |
| Anneke | Dutch variety that was found in Groningen, large rounded nut with sharp point. | Pot Sept 2024 | |
| Blunt | Unique above heartnuts, seedling of Covel Manchurian with the same blunt nose and sweet taste, tight in the shell but cracks our whole. | Pot Sept 2024 | |
| Campbell CW1 | Canadian Heartnut that produces a good crop of medium/large nuts, partly self-fertile, late pollinator. |  | December 2024 |
| Campbell CW3 | A heavy producer of medium sized nuts on a more compact tree. The nuts will crack out a mixture of halves and whole meats that drop out of the shell freely. It is an early pollinizer. |  | Pot Sept 2024 |
| Campbell CW4 | Heartnut bread by Doug Campbell of Ontario, Early pollinator, Compact tree with a good yield of medium size nuts, late pollinator. |  | Pot Sept 2024 |
| Char | Listed by Cliff England in 2005, a very large nut. Selected in Korea and imported about 2000 into the USA. Tree is a very vigorous grower and precocious with thin shell and high ratio of kernel to shell crack out. Trees have an upright growth habit that is desired for planting in a yard setting. Nut is large round heart-shaped and fills well. | Pot now 2024 | |
| England's Best | Large Size, Large Kernel, Wide Cavity, not convoluted Great taste. Heavy Crop, thin shell | Pot now 2024 | |
| Fodermaier | This is an older heartnut selection from Dover Plains NY. It is rated high for cracking quality and production. It produces a large nut which drop out in halves and it ripens mid October. Protandrous , early pollinator. |  | None |
| Frank | Supposedly the latest heartnut to leaf out, medium sized nut that cracks out well. | December 2024 | |
| Grimo Manchurican | US Heartnut that produces a good crop of medium sized easily cracked nuts, partly self-fertile | None | |
| Imschu | Reliable heavy cropping Canadian Heartnut that has medium sized nuts that crack out whole. Partly self-fertile and late pollinator. |  | Pot Sept 2024 |
| Jewel Box | This cultivar of Heartnut was developed in Kentucky. It has a very large nut, and is a good producer; steady cropping every year. | None | |
| Kalmar | 'Kalmar' originates from the park around Stagneliusskolan in Kalmar. The yield fluctuates a lot from year to year and can be extremely high in good years. Like other heart nuts, the tree can be affected by late spring frosts. Grown from swedish seed. A Swedish variety. Rather convex nuts with deep dimples inside the shell. Big, easy to crack, on average 6 grams heavy | December 2024 | |
| Locket | Flavour of black walnuts, Large round pointed nut | December 2024 | |
| Schubert | Canadian Heartnut that produces medium nuts, partly self-fertile, late flowering and vigorous tree, parent of Imschu. |  | None |
| Simcoe | Simcoe' formerly 'Simcoe 8-2' was selected from a planting at the Simcoe Station Experimental Farm. It is a large Valentine heart shaped nut that freely drops out a mixture of whole and half nutmeats. It is an alternate bearer on a two-three year cycle with heavy and lighter crops. It is an early pollinizer | December 2024 | |
| Stealth | A large elongated nut and a moderate producer. The nut meat drops freely out of the shell whole. It is an early pollinizer. Nuts ripen 2 weeks after 'Imshu'. |  | Pot now 2024 |