Because walnut trees grow so large and take so many years to come into cropping, they are seldom planted. Nowadays, however, it is possible to grow walnuts as bush trees, which come into cropping earlier.
SOIL AND PREPARATION
Walnuts will grow on almost anybut prefer a well-drained clay with a fair lime content. Where trees are planted in sandy soils, mulch the soil round them after planting, using old rotted compost 3 in. deep in a ring 3 ft. wide. No special soil preparation is necessary.
As walnutare easily ruined by frost, it is essential to plant the trees in a frost-free place, preferably on fairly high ground. Avoid depressions and low spots where frozen air tends to collect.
Plant between November and January. Dig a hole 9 in. deep and 3 ft. across.
Spread the roots out evenly and cover with soil gradually, treading down well as the planting proceeds.
Each March apply bone meal all over the ground at the rate of 2 oz. per sq. yd. And, in addition, give young trees a mulch of rotted compost or leaf mould in spring.
The propagation of walnuts is specialized work for the nurseryman.
In July, when about six good leaves have formed, cut back the leaders by a quarter just above’a bud and aim at keeping the tops of the branches level. As a result flower buds will then form on the lower parts of the shoots. Do not pinch back any weak laterals at that time for they will usually be the bearers of male catkins. Do not prune walnuts at any time between November and May.
It is important to grow a variety that has plenty of male catkins. Some kinds produce male catkins long before the female catkins are ready to be fertilized. In such cases plant another variety which will produce male catkins at the right time.
Walnuts for pickling should be gathered when the shells are quite soft. The ripe fruits drop and the shells split.
Franquette, large, pointed, strongly shelled. Produces leaves late. Less susceptible to May frosts than other varieties.
Mayette, large, roundish, with thin shells flattened at one end. Easy to crack.
Northdown, oblong. Young growth is bronze in spring.