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Everybody recognises palm trees, they are the universal symbol for the tropics but many are hardy enough for our temperate climate gardens. Until recently New Zealand gardeners have had only a very limited range of palms to choose from. In the last five years the range has grown enormously as nurseries have been encouraged by gardeners eager to experiment. Nevertheless, palms are, on the whole, slightly tender plants. Those that will tolerate regular frosts of -6°C. or more are few in number. If your minimum temperature does not drop below -2°C or if you are in a frost free area the range of suitable plants increases considerably. There are two main styles of palms; the fan and the feather. The names refer to the layout of the fronds. Fan palms have the leaflets of the frond arranged just like a hand operated fan. The most widely grown fan palm is Trachycarpus fortunei, the Chinese Fan Palm. Feather palms have the leaflets of their fronds arranged along a rigid midrib like a bird's feather. The most commonly grown feather palm is Phoenix canariensis, the Canary Island Date Palm. Palms are extremely important plants to the world's economy. The true date palm or commerce, Phoenix dactylifera, is rarely seen in New Zealand but is the most common commercially grown palm. The coconut, Cocos nucifera, is not far behind. Possibly more significant than fruit crops is the use of palms for shelter. Virtually every tropical third world village relies on palms as a roofing material. Although palms are associated with sun and sand most species appreciate light shade when young. Shelter from wind is important if the fronds are to look their best but as the plants eventually become quite large they will eventually have to tolerate exposure to sun and wind. When siting a palm remember to take into account the spread of the crown. This is not so significant with a mature plant as the crown is usually well above most obstructions. The problem is adolescent plants, which tend to have much the same spread as adults without the height. They take up a considerable area until the trunk begins to develop. Palms generally do best in a rich, moist well-drained soil. They have fairly strong roots that anchor them firmly. The roots of many palms can withstand a considerable amount of abuse, which enables the trees to be safely transplanted at almost any size. Many palms are frost tender but there are quite a few that tolerate reasonably tough frosts. The best known are Phoenix canariensis and Trachycarpus fortunei but you should also consider Jubaea chilensis, Chamaerops humilis, Butia capitata, Washingtonia robusta and Brahea armata. Palms often grow well in coastal conditions but benefit from occasional wash downs to remove any salt spray deposits. Palms often make superb container plants, both indoors and outdoors. Many are undemanding and tolerant of neglect. In cold areas it's often best to keep young palms in containers until well established. That way they can be moved under cover for winter. Once they have a spread of over 1.5 m or so they should be hardy enough to plant out but if it's not inconvenient it's better to wait as long as possible. Palms are nearly always propagated by seed. They usually have only one growing point so vegetative propagation is not practical. Occasionally suckers form at the base of established plants and may be carefully removed for growing on but this is not a reliable method of propagation. Palm seed varies greatly in its ease of germination. The most common problem is very hard seed coats. No amount of scarification or soaking will soften the toughest of them. Sometimes acid treatment is resorted to but patience is the usual method. Some, such as Butia capitata, may take upwards of a year in the soil before germination but eventually with the right c
germinate easily. Two species of this genera are suitable for growing outdoors in mild areas. Both are feather palms with broad leaves that have silvery undersides. Arenga pinnata requires near frost free conditions but Arenga engleri from Taiwan will tolerate infrequent light frosts. Both species have interesting flowering habits and fruit. Arenga pinnata is monocarpic; it dies after flowering although it takes at least ten years to reach maturity. Arenga engleri survives to flower again but the leaf stem beside the flower stalk dies. Both species have fruit with extremely caustic pulp. Both species are unlikely to exceed 3.5 m high under New Zealand conditions but Arenga pinnata may reach 18 m high in its native South East Asian region. Arenga pinnata seed germinates quickly and easily but Arenga engleri is erratic and may take several months to sprout. Not usually grown indoors. These fan palms are becoming more common in New Zealand gardens. Both of the common species Mexican Blue Palm (Brahea armata) and Guadeloupe Palm (Brahea edulis), are reasonably hardy and adaptable plants. B. armata has beautiful, finely divided glaucous fronds. It is the hardier of the two and will withstand -8°C once established. It has a stocky trunk for many years but may eventually reach 12 m high. Brahea edulis is tender when young but withstands -6°C once the trunk is over 10-15 cm diameter. It grows slowly to about 15 m high. Both species are tolerant of drought and low humidity. Brahea armata has 12 mm diameter brown fruit, while Brahea edulis has edible 18 mm diameter blackish fruit. Grow in full sun. The germination of Brahea armata seed is very erratic and may take up to year. Brahea edulis is less tricky but still not very reliable. High light requirements make Brahea unsuitable for indoor cultivation. The Yatay, Pindo Palm or Jelly Palm (Butia capitata) from Brazil is a hardy feather palm with long drooping olive to bluish green fronds. It will withstand -10°C once established and deserves to be more extensively grown. It grows to about 7 m high. The flowers are followed by yellow to red 25 mm diameter pulpy fruit. Grow in full sun. Seed germination is highly variable, it is unlikely to take less than two months and may be a year or more. High light requirements mean this palm is not very suitable for growing indoors. The Fishtail Palm (Caryota mitis) is often grown as a house plant and is unlikely to grow well outdoors except in the very far north. Caryota urens has slightly lower heat requirements but will not tolerate any frost. It has very dark green, slightly arching fronds. All Caryota palms have intricately cut bipinnate feather fronds. Most species grow to large sizes (over 18 m high) in the tropics but are unlikely to exceed 8 m high under New Zealand conditions. They have fruit with caustic pulp that should not be handled with bare hands. The seed germinates easily. Caryota palms grow well indoors but prefer warmth and high humidity. The Mediterranean Fan Palm (Chamaerops humilis) is a bushy fan palm that is usually multi-trunked and will not exceed 6 m high. The trunks take many years to form and are seldom seen in gardens. Most plants grow to about 1.5 m high x 5 m wide. The fronds are tipped with sharp spines. It is a very hardy palm that tolerates -15°C. Tolerant of low humidity and drought. Grow in full sun. The seed germinate well and takes about six weeks to sprout. High light requirements and sharp spines make it unsuitable for indoor use. Fishtail palm-see CaryotaHoweaVery popular indoors but capable of growing outdoors in frost free areas, these palms were formerly classified as Kentia and are still widely known by that name. Two species, Howea belmoreana and Howea forsterana, are grown. Both are natives of Lord Howe Island. They are feather palms with deep green gracefully arching fronds and narrow trunks. Howea belmoreana grows to about 7 m high and Howea forsterana about 15 m high but both are unlikely to reach these sizes in New Zealand gardens. They have brown olive sized fruit that takes two years to ripen. Only very fresh seed will germinate and even then it is erratic. Both species need shade when young, which is why they perform well indoors. JubaeaThe Chilean Wine Palm (Jubaea chilensis) is a hardy (-8°C) feather palm that should be more widely grown. It has deep green arching fronds and a very distinctive trunk. The trunk becomes greatly enlarged, rather like a baobab tree, so that when mature it may be up 2 m diameter. Within the trunk is a large reserve of sap, which may be tapped and fermented into an alcoholic drink, hence the name Wine Palm. This palm can grow to 20 m high or more but it takes many years to get above 10 m high. The 40 mm diameter fruit is yellow and the seed it contains germinates easily but takes about four months to sprout. May be grown indoors but has high light requirements. Kentia-see HoweaLady palm-see RhapisLivistonaThese fan palms are native to South East Asia and Australia. Two species, Livistona australis and Livistona chinensis, are suitable for growing outdoors in mild areas. They are very similar to one another. Both have deep green spiny fronds with leaflets that droop and fray at the tips. They have quite solidly built trunks that grow to about 12-15 m high. Under New Zealand conditions it takes many years for them to reach 10 m high. Both species are hardy to about -5°C when well-established. Livistona australis has 18 mm diameter reddish fruit and Livistona chinensis has 25 mm diameter green fruit. The seed of both species germinates easily and quickly. May be grown as house plants but they have high light requirements. Nikau-see RhopalostylisPalmetto-see SabalPhoenixThe Canary Island Date Palm is by far the most common feather palm grown in New Zealand gardens. It has deep green arching fronds and a trunk studded with bases of old fronds. When young, the trunk tends to be quite bulbous but as it gains height it becomes more tree-like. A mature tree may be up to 18 m high and have a very solid trunk. The fruit is about 40 mm diameter and yellowish orange. Phoenix dactylifera is the true 'Date Palm' of commerce that is such a well-known symbol of North Africa and the Middle East. It has shorter fronds in a less dense head than Phoenix canariensis. It is much taller when mature, up to 25 m high. Both Phoenix canariensis and Phoenix dactylifera will withstand -8°C when established but should not be exposed to hard frosts until the have a short trunk. Phoenix dactylifera needs hot summers to grow well and is unlikely to produce edible dates in a cool summer climate. A third species, the Pygmy Date Palm (Phoenix roebelinii) is considerably less hardy but it can be grown outdoors in frost free areas. It is frequently used as a container plant as it only grows to about 3 m high. There are several other species that would be suitable for growing in New Zealand gardens but they are rarely seen . Among those most likely to do well are Phoenix loureiri, Phoenix rupicola and Phoenix sylvestris. All Phoenix palm seeds germinates quickly and easily. All species make excellent house plants when young. Go to SITEMAP
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