Walnuts – are an excellent source of plant based omega 3 fatty acids, known for fighting heart disease. They are also packed with micronutrients, antioxidants and plant sterol, which lower cholesterol.
Walnuts also provide protein and phosphorus as well as vitamins B and D. Eat nuts in moderation though as they are quite high in calories – perhaps a handful up to five times a week. Oil made from the nuts is delicious in salads or on pasta dishes.
Common walnut (Juglans regia) is a beautiful, slow growing, deciduous tree that may grow to around 15meters/50feet tall with a spread of about 10meters/30feet. Because of it’s potential mature size give some thought to its permanent position as not all back yards are able to accommodate such a tree. Even though they will tolerate heavy pruning, they shouldn’t be planted near drains or buildings.
It is a cool-climate tree and prefers a sunny position. The mature tree is quite frost hardy, but young plants and new spring growth are vulnerable to frost damage. Walnut trees prefer deep, rich, well drained soils with regular watering through summer and plenty of light.
Grafted plants will produce much better fruit than trees grown from seed. The cultivar ‘Wilson’s Wonder’ fruits at around 7 years, much sooner than most others. It is best to plant out young trees in winter, while leafless.
Barely noticeable female flowers grow on the current years growth and greenish/yellow male catkins hang from last seasons twigs on the same tree in spring, just before the large pinnate leaves appear.
The fruits are oval in shape and are 4-5cm across.
The hard shelled nuts form inside green husks that turn dark brown when ripe. The tasty kernel is found inside the hard outer shell.
The fruit should be collected from the ground in autumn (fall) once they have withered and fallen from the tree.
Use gloves to remove the husk from the white kernel inside, to prevent staining your hands.
Black walnut (Juglans nigra) produces the toxin juglone, which is emitted via its roots. Many plants that come into contact with it will wilt or die because this toxin is so strong.
Leaves that fall from walnut trees, as well as the husks, are toxic to other plants, so don’t include them in your general composting.
They are also very poisonous to fish and most animals.
The outer husks can be used to make a brown dye.
Some species are grown specifically for their yield of fine timber for furniture production. Sometimes they are just grown for their elegant, aromatic foliage and remarkable form.