Juglans × bixbyi
Common Name: Buartnut
Juglans x bisbyi is a vigorous, sprawling, deciduous tree that can grow up to 20 metres tall.
The tree is a hybrid of garden origin between the N. American Juglans cinerea and the Asian Juglans ailantifilia. Several cultivars have been developed from this cross and are grown commercially for their edible nuts[
A hybrid of garden origin, Juglans cinerea x Juglans ailanthifolia cordiformis.
Not known in the wild.
Requires a deep well-drained loam and a sunny position sheltered from strong winds[
]. Prefers a slightly alkaline soil[
Plants are fast-growing and grafted plants can commence producing fruit when around 3 - 4 years old[
Flower initiation depends upon suitable conditions in the previous summer[
]. The flowers and young growths can be destroyed by even short periods down to -2°c, but fortunately plants are usually late coming into leaf[
By nature a sprawling tree, it is said to be almost impossible to prune it into a decent shape[
]. Any pruning should only be carried out in late summer to early autumn or when the plant is fully dormant otherwise wounds will bleed profusely and this will severely weaken the tree[
Plants produce a deep taproot and they are intolerant of root disturbance[
]. Seedlings should be planted out into their permanent positions as soon as possible and given some protection for their first winter or two since they are somewhat tender when young[
A hybrid, Juglans cinerea x Juglans ailanthifolia cordiformis, it is sometimes cultivated for its edible seed, there are some named varieties[
]. This hybrid combines the best qualities of each parent[
] - the aromatic kernel flavour and superior climatic adaptability of Juglans cinerea with the higher yields, better appearance and crackability of Juglans ailanthifolia cordiformis[
Seed - raw[
]. The shell is thin and the seed well-flavoured[
An edible oil is obtained from the seed, it tends to go rancid quickly.
Plants produce chemicals which can inhibit the growth of other plants. These chemicals are dissolved out of the leaves when it rains and are washed down to the ground below, reducing the growth of plants under the tree[
]. The roots of many members of this genus produce substances that are toxic to many plant species, especially apples (Malus species), members of the Ericaceae, Potentilla spp and the white pines (certain Pinus spp.)[
The seed is best sown as soon as it is ripe in individual deep pots in a cold frame[
]. You need to protect it from mice, birds, squirrels etc. The seed usually germinates in late winter or the spring. Plant out the seedlings into their permanent positions in early summer and give some protection from the cold for their first winter or two.
The seed can also be stored in cool moist conditions (such s the salad compartment of a fridge) over the winter and sown in early spring but it may then require a period of cold stratification before it will germinate[
]. This is a hybrid species and so it might not breed true from seed.