Punicaceae – Punica granatum – Chinese Apple, Melagrana
Pomegranates are believed to have originated in the area from what is now Iran to the Himalayas of Northern India, and from there spread throughout the whole Mediterranean region, and as far as China where they have been cultivated for thousands of years. The climates they have evolved in make them totally suitable for most parts of South Australia.
The pomegranate is a shrub or small tree that can grow to 6 to 10 metres, but more typically 3 to 5 metres in height. In our region it is generally deciduous, but some varieties will recover their leaves after a very short break. The new leaves are bronze coloured turning a deep glossy green with maturity. The trunk is covered by a red-brown bark which becomes grey with age, and branches are stiff and angular, and often thorny, although this varies greatly by variety. The root system is fibrous and quite extensive and there is a strong tendency to sucker from the base. Pomegranates are long-lived, with some specimens in Europe known to be over 200 years old.
Apart from the varieties grown for fruit, there are also ornamental types. The dwarf variety ‘nana’ grows to about 1 metre with small decorative fruit and there are also ornamental types with double and variegated flowers, one such cultivar is on display at the Adelaide Botanic Gardens.
According to the International Plant Genetic Resources Institute (IPGRI), more than 500 named varieties are listed World-wide, but as is the case with other species e.g. figs, the probability of duplication is high due to one variety being known under different names in varying localities.
There are also a large number of un-named varieties available, many of good quality. Some may be seedlings while others could be heirloom varieties introduced by early immigrants and handed down through generations.
Pomegranates grow best in warm areas, with hot dry Summers and wet Winters, in other words in our Mediterranean climate. In inland areas which can be much hotter the fruit can suffer from sunburn. Excessive rainfall in Summer and early Autumn can cause the fruit to split, but this can be avoided to some degree by maintaining an even soil moisture through irrigation. Established plants are able to survive frosts to minus 10°C.
Soils can be variable, but must be well drained. Ideally the pH should be 5.5 to 7.0, but they will grow equally well in more acidic or alkaline soils.
Pomegranates have good drought tolerance but for quality fruit watering is necessary, otherwise the fruit will tend to be small and astringent. Pomegranates can tolerate higher salinity levels than most other fruit trees. Best results are obtained with best quality water but they would probably tolerate watering with greywater better than some other species.
Pomegranates are easily grown from seed and many seedlings go on to produce fruit of acceptable quality. Remember that even the best of the recognised varieties were seedling selections. Selected cultivars are easily reproduced by means of hardwood cuttings taken when the plants are dormant, and struck in sharp sand or potting mix in July or early August. Cuttings should be around 20 to 30cm in length and pencil thick.
Keep the developing plants in a sheltered position and use a complete slow release fertiliser. Plant out the following Spring when the plants have attained a good size.
When planting out, plant to the same depth it was in the pot. Don’t put any fertiliser into the planting hole but you can apply some to the soil surface after back-filling, pelleted organic fertilisers are best. This is also a good time to apply an organic mulch.
The fertiliser requirements of pomegranates are less than other fruit trees. A pelleted organic fertiliser applied twice yearly, in Spring and then again in early Autumn, should suffice for the home gardener.