Almonds
Almond is also the name of the edible and widely cultivated nut of this tree.
Although popularly referred to as a nut, the almond fruit's seed is botanically not a true nut, but the seed of a drupe (a botanic name for a type of fruit).
Originating in central Asia, almonds have been used as a valuable food source since ancient Greek times. The healthiest of all the nuts, almonds contain protein, carbohydrate and concentrations of calcium, phosphorus and magnesium, as well as vitamins from groups B and E. They also have high content of fat (both mono-unsaturated and polyunsaturated) and the highest fibre content of any nut or seed. There are two types of almond, the bitter, used for almond essence, and the sweet, grown in home gardens and perfect for eating.
In Virginia, on the North Adelaide plains, Jim Pierson and his son, Benjamin, are professional growers in one of the key almond-producing areas of Australia. Warm temperate to cool temperate are ideal climates, where the winters are wet, springs are drier and summers hot.
Almonds can tolerate light frosts and require a chill factor in winter of 300 hours of temperatures below 7 degrees before they will bloom. Frosts after flowering can wipe out the entire crop. Almond trees will not bear fruit for the first two years, while in the third year there should be a handful of fruit. By their eighth year they should be bearing up to 8kg per plant, just a small part of the Australian production of about 8,000 tonnes a year.
Almonds are non-self-fertile. Two plants of different, but compatible, cultivars are needed so they can cross-pollinate to achieve fruit-set. Currently, there is a lot of work being done on developing a prolific nut producing, self-fertile almond. In the meantime, it is possible to buy grafted compatible varieties of almonds to reduce the need for two trees.
The home gardener has three types of almonds to choose from - paper shell, which are easy to break open in your hand,soft shell, which can be opened by crushing against another nut, and hard shell, which need a nutcracker to open. Paper shell varieties, such as ‘Nonpareil’, IXL’ and ‘Ne Plus Ultra’, and soft shell varieties, such as ‘Brandis Jordan’ and 'Johnston Prolific' are available as bare-rooted plants in most nurseries now. Hard shell varieties, such as ‘Peerless’, ‘Fritz’ and ‘Mission’ may need some searching to find.
When almond trees are first planted, it's important to give them a boost with superphosphate, following up with a balanced plant food in autumn and spring thereafter. Although the trees can survive on little water, to produce a maximum crop of nuts they need possibly the most water of any cropping tree. In spite of limited water supplies, the Piersons use sprinklers over the whole orchard floor to ensure that all roots get sufficient water. The resulting well-developed root system allows the trees to take advantage of the natural rainfall. Almond trees love mulch right around and out to the drip line, but they must have good drainage, as they will drown if waterlogged.
Almonds are harvested when the outer, fleshy hull starts to split open. Collect the nuts from the outer canopy of the tree first, by spreading a tarp on the ground below and knocking the tree. A couple of weeks later the nuts on the inner canopy will have ripened and can be harvested in the same way.
In this area, the trees are subject to attack from hungry hares, so the Piersons protect their young trees with tree guards. The trees will also need secure netting to keep off birds which have a fondness for the nuts.