How to grow persimmons
The persimmon most commonly found in New Zealand is the Asian or Japanese type (Diospyros kaki), a native of China that divides into astringent, cheek-puckering varieties or the hybridised sweet ones that now dominate production.
Other lesser-known species are the American persimmon (Diospyros virginiana), mainly grown for its timber, which is turned into billiard cues and drum sticks, and the black persimmon (Diospyros digyna), which is also known as the black sapote and is a native of Mexico so can only be grown in frost-free areas.
Persimmons are a relatively new commercial fruit crop in New Zealand, with around 15,000 tonnes produced here annually. The main production areas are Gisborne and around Auckland, with smaller orchards also found in Northland, Waikato, the Bay of Plenty and Hawke's Bay.
Although the commercial growing areas are located in the warmer regions to guarantee an annual crop, persimmons in fact crop really well in most of our cooler regions too. Growing as a native in the temperate parts of China, persimmon trees are hardy to -10C, going into deciduous dormancy during the winter months.
In spring, the trees leaf up late and flower even later, around November and December, so there is very little risk of frost damage on the young shoots and blooms. The fruit just needs a long, warm summer to ripen, up to seven months. In seasons that are too cool or too short, even non-astringent varieties can produce somewhat astringent fruit, although the fruit will continue to ripen in temperatures down to around -3C.
The non-astringent types of Diospyros kaki are by far the most popular. Varieties like 'Fuyu' (meaning winter persimmon), 'Matsumoto Wase Fuyu' and 'Jiro' are tomato-shaped, with richly deep orange skin when ready to pick from May to July.
The fruit can be eaten freshly picked from the tree like an apple, or sliced into crisp, sweet, melon-like wedges, skin and all. The crisp fruit can be popped in a paper bag for a couple of days with an apple to release ethylene which will ripen them. The stem end can then be sliced off to scoop out the jelly-like flesh.
The fruit will store well at room temperature for 20 to 30 days, or can be chilled at 0C in plastic bags for longer storage. Persimmons can be cooked into chutney, marmalade or jam, or can be made into a delicious sorbet.
The rarer, astringent types like 'Hiratanenashi' are longer and peach-shaped. To make them more mellow, leave the fruit to fully ripen until red and very soft. It can then be eaten chilled or scooped out with a spoon.
The black persimmon (or chocolate pudding fruit) hails from Mexico so naturally needs a warm climate. It is unlikely to prosper anywhere south of Auckland. The fruit has blotchy green skin that contains chocolate-mousse-like sweet, dark flesh.
Track one of these rare trees down on Trade Me or try subtropica.co.nz.
The sensitive tap root system of persimmon trees means that the roots can struggle in heavy clay, so they are best planted in free-draining soil. This also means the trees are not suitable for growing in containers - the sensitive roots can't handle the extremes of dry and wet that are difficult to control in a pot.
The branches can be rather brittle, so a sheltered site must be selected to ensure the tree is protected from strong wind. And don't be greedy with the fruit - the branches can break under the strain of a heavy crop. Thin the fruit in mid to late summer if the limbs are straining. I have seen a beautiful young tree split in two under the weight of its first heavy crop.
Small gardens can feature a persimmon tree as a specimen, as it is a very manageable size for spots with limited space. Left to its own devices, it will reach about 3m tall by 2m wide, but can be kept smaller through pruning.
Persimmons naturally grow into a rounded to pyramid-shaped tree, with somewhat pendulous branches (especially when weighed down with fruit).
For very small urban gardens, persimmon trees make a beautiful wall feature as an espaliered form, with arching branches covered with orange fruit lanterns and beautiful bright autumn foliage colours. Train the young shoots in summer when the sap is flowing so the branches are more supple. Don't bend older limbs in winter when the wood has lignified, or hardened.
Hungry persimmon-lovers may need a bit of patience, as the tree can take three to five years to produce a crop of any consequence. But the wait is well worth it: once in production, you may have more fruit than you know what to do with.
A young tree can produce 20-40kg each year, but a mature one produces as much as 100kg a season. Lucky birds, especially waxeyes, will love any crop you don't harvest.
The persimmons will stay on the tree right into the winter, with the birds pecking the flesh out of the fruit, leaving an orange lantern-like shell of the skin hanging on the tree.
The fruit is produced on new wood, which forms on the terminal buds of the previous season's growth.
Persimmon trees are propagated by raising seedlings - nurseries usually import clean persimmon seeds from specialist suppliers in the United States or Japan - which take around three years to grow to a graftable thickness.(This is about 8mm thick in the trunk at the graft point, which is usually 15-20cm from the soil level.)
The seeds are sown in trays, then are gradually moved into larger pot sizes, usually being supplied in tall, slender planter bags to accommodate the long tap root (known as a PB10, which equates to 10 pints of potting mix capacity).
The variety is grafted on to the rootstock using a whip and tongue graft in mid to late spring, which grows quickly to a tree that can be sold at around 1m tall by the end of the summer. Because of this long production cycle, persimmon trees are one of the most expensive fruit trees for home orchardists to purchase, usually retailing for at least $50.
Pollination is an interesting subject with persimmons. Most varieties are parthenocarpic, which means that the flowers do not need cross-pollination to produce fruit. (Indeed, cross pollination is usually not desirable as it results in seeds in the fruit.)
Pollinated flowers tend to produce larger fruit, however, and have a different flavour and texture to seedless fruits. The flowers are inconspicuous, cream-coloured when female or pink-tinged when male, hidden amid the lime-green new foliage.
PESTS AND DISEASES
Persimmon trees are low-maintenance, easy-care plants with very few potential pest or disease problems. Thrips, mites, leaf-roller and mealy bug can be problematic in warmer climates, although these can be easily treated by smothering with an organic neem oil application in the early stages of infection.
Thrips give the leaves a silvered appearance and can spread quickly, whereas mites can lead to leaves having a rather mottled look because the sucking insects drain the foliage of chlorophyll.
Birds could be considered pests, although there is usually more than enough fruit to share with our feathered friends as well as to enjoy ourselves. Cover the tree with bird netting if necessary.
For more like this subscribe to NZ Gardener at mags4gifts.co.nz
- NZ Gardener