The middle of April is the time for the walnut harvest, a nut that provides a valuable dietary source of phosphorous. We have waited for quite some years for our established walnut tree to produce a crop and so it is with some delight that we are now harvesting a small crop. The husks are opening up around the shells right now.
The European walnut (Juglans regia) originated in Persia but was introduced into western Europe before the time of Christ. It was to become an important ford source, as well as a source of high grade timber. The black walnut (Juglans nigra) was a native of North America and was introduced to Europe via England in 1686.
Walnuts grow best in deep, well-drained soil, where their roots can penetrate deeply. Unlike all other fruit and nut trees, the walnut has a tap root, similar to all eucalypts. So it needs to be able to drill down into metres of soil below the surface and not get stopped by subsoil rock formations.
One of the best specimens of local walnut trees is in the front of Bert Hauptmann's apple orchard at Pialligo. This does affirm the old adage that walnuts will grow where apples grow well. As with apples, the walnut tree requires around 800 chill hours over winter to produce good springtime flowering.
Walnut trees can grow to way beyond 10 metres high, with records of some mature trees exceeding 20 metres. The trees are long living ,with some recorded in North America as being around 200 years old. When planted in the right conditions an initial crop can be expected after just five or six years and full production should be reached after another five years. However, you may find a tree planted in the Canberra region will take up to 10 years to begin cropping.
The early plantations allowed spacings of 15-16 metres between trees but newer plantations have reduced the spacing to 10-12 metres. They can grow to be huge trees indeed.
Historically in Australia, there was a concentration of planting walnuts in the rich soils of Victoria. However, in the past decade major new plantings have been undertaken in New South Wales and Western Australia. The big new commercial walnut plantation on the outskirts of Leeton is now advancing well and the trees look very healthy. Combined with a plantation in Tasmania, this grand new venture is aiming to produce 11,000 tonnes of walnuts in shell a year within the next decade.
Franquette is a good quality specimen originating from France, with consistent yields, year by year. It has been planted widely in Australia. It flowers late so misses the heavy frost periods. Eureka and Wilsons Wonder are two productive cultivars that were bred in California. Their nuts are quite large and relatively symmetrical. Freshford Gem was raised first in South Australia. It produces heavy crops and bears quite early, around six years after planting. The nut is medium sized and has a thin skin which can be opened easily.
If you have just one or two trees in the backyard, then you can knock the walnuts down with a long wooden pole. Of course, the big commercial orchards in the southern states of Australia will use big machines to mechanically shake the trees, during April.
It is important to quickly remove the husk around the walnut shell, so that the drying process can begin. It is best to clean up the shell and dry the walnuts as quickly as possible. Dry by placing the unshelled walnuts onto a drying rack in a spot that keeps warm and allows air to circulate. This will take around two weeks and over that time the moisture content of the nuts will have dropped from 25 per cent to below 10 per cent.
When well dry, walnuts can be stored for up to a year, in shell. Farmers Markets are a good source of local walnuts in shell, direct from the grower, during autumn.
The timber of the tree is one of the most beautiful timbers in the world. However, with the relatively slow process to maturity, you will probably need to adopt the maxim of 'growing nut trees to benefit your grandchildren'. Still it is a worthy possibility to consider as you come to the winter planting time.
Date and walnut loaf
A favourite recipe, especially with fresh walnuts.
1 cup self raising flour
½ cup raw sugar
½ teaspoon bicarb soda
2 teaspoons cinnamon
½ cup chopped dates
½ cup chopped walnuts
30g butter
⅔ cup water
Preheat oven to 170°C. Sift the flour with the cinnamon and bicarb soda in a medium sized bowl then stir in the sugar. Add the chopped dates and walnut pieces.
Heat the butter and water in a small saucepan until the water just comes to the boil. Make a well in the middle of the dry ingredients and pour in the heated butter/water. Mix thoroughly. Spoon into a greased medium sized bar tin. Bake for approximately 40 minutes. May serve slices with a thin spreading of butter.
This week in the garden
* Plant out a selection of leeks, shallots, kale, radish and beetroot into well prepared garden beds.
* Complete preparing a garden bed for planting out your annual garlic patch and build up to provide for very good drainage. Plant with quality Australian grown seed garlic.
* Plant broad beans into garden beds that need to be renewed. You can then turn in the plants when they are half grown to provide a good source of organic matter for later crops. Otherwise allow the plants to continue growing and produce an early spring crop of tender beans.
* Granny smith and Rome beauty apples should be allowed to remain on the tree until the first frosts come, to fully ripen and sweeten up. Golden granny smith apples are a delight to eat and with the natural grease cover on the skin can be kept into the winter months.
* When cleaning up garden beds of corn, beans and pumpkins, cut up the remains of the stalks and vines before composting, to help a speedy decomposition process. Do not put old tomato vines in the compost as they can carry diseases.
Owen Pidgeon runs the Loriendale Organic Orchard near Hall.