Growing walnuts as a commercial crop has two advantages - one can market the fruit, sell the wood for lumber or a combination of both. Walnut is a hard wood and is always in demand by furniture makers and fetches a high price.
The downside is walnut isn’t a fast growing crop and like all hardwoods is slow growing. A newly planted orchard would not produce any nuts for around twelve years and one would have to wait another twelve to fifteen years before the trees could be felled for timber.
Also the farmer needs to bear in mind the climate as walnuts do not grow anywhere and need a warm climate where there are no frosts at all. Walnuts need a dry location with moderate rainfall or adequate irrigation. Also Walnuts need somewhere where sunshine is plentiful. Walnut trees are large and to grow a commercial orchard full would require a field of several acres to be profitable.
If one intends to grow walnuts for both a nut harvest and timber they will need to stagger the planting of trees to always be sure there are enough trees for both fruit and lumber to maintain continuous production. The soil will also need to be tested for suitability before sowing any crops. Soil testing equipment can be purchased from specialist stores. Once a field has been chosen, all other crops or vegetation will need to be removed and freshly ploughed.
Walnuts should be planted in the spring and will need to be eighteen feet apart in all directions. This is a large tree and will need a lot of space. Using the above guideline one should be able to plant approximately twenty five trees per acre of land. If you are planting for timber production only, the trees can be slightly closer together but should remain at least fifteen feet apart in all directions to allow for adequate growth. When planting new crops one must expect ten percent loss of new saplings which should be replanted each spring.
It is recommended to use a nitrogen fertiliser at least once per annum. The trees should be pruned each spring during to remove all the lower branches. Walnut trees begin to produce fruit when twelve years old and will give maximum production for around twenty five years then the harvest will decline. At this stage the farmer may consider felling the wood for lumber and replanting.