Phoenix canariensis
(Canary Island date palm)

P. canariensis has been widely introduced for centuries and is one of the most commonly grown and appreciated ornamental palms of the world. It has recently been noted naturalising and becoming invasive in southern California and northern New Zealand, mostly in riverine wetland and coastal habitats. Planted widely, seeds are eaten and spread by birds, and can be washed down watercourses where established. However, control is likely to prove less difficult as compared with other invasive plants.

P. canariensis has been designated as a Research Pest in Auckland, New Zealand, and it is on the 2006 Cal-IPC Invasive Plant Inventory for California, USA (DiTomaso and Healy, 2006). However, it is widely available as an ornamental palm, and is available as seed, seedlings, potted plants and planted stock from many nurseries and internet businesses. Risk of introduction is high, though it is likely that it may already be present in most areas having a suitable climate.

In its native range on the Canary Islands, P. canariensis grows on a wide variety of soils, in areas from 200 to 600 m altitude (Santos Guerra, 1994; Morici, 1998). Where introduced, it is a common ornamental in urban and coastal areas, and has spread mainly in disturbed riverine areas, but also to a limited extent in coastal areas and wetlands, such as in southern California (DiTomaso and Healy, 2006).

Genetics

P. canariensis has a chromosome number of 36, the same as that of P. dactvlifera, P. reclinata and other species thatare known to be able to hybridise with it (Beal, 1937).

Reproductive Biology

Like P. dactylifera, P. canariensis is dioecious, and may not start to produce fruit until it is at least 5-10 years old. P. canariensis is often described as anemophilous (wind pollinated), though is likely to be pollinated, at least in part, by the weevil Neoderelomus piriformis (Coleoptera, Curculionidae, Derelomini)(Meekijjaroenroj, 2004). The fruit ripens in summer. It is interesting to note that this pollinator now appears to be spreading, with first records on P. canariensis from France (Piry and Gompel, 2002), and Israel, where it is also noted as an invasive species (Friedman, 2006). P. canariensis trees, especially in more humid climates.

Physiology and Phenology

It is a very slow growing tree especially in early establishment.

Associations

Various epiphytes are commonly seen growing in the crowns of large P. canariensis trees, especially in more humid climates. Organic matter tends to collect at the bases of fronds thus providing a suitable environment for such plants to grow and thrive.
 

Environmental Requirements

The palms are found growing on a wide variety of soils, and P. canariensis has an extensive root system for finding sub-surface water, and is also resistant to temporary waterlogging caused by sudden rains. In urban environments where P. canariensis is often introduced as an ornamental, this species can thrive in a variety of habitats and soil types (Gilman and Watson, 1994). It can withstand light frosts when mature though it is frost-sensitive as a seedling and during early establishment. It can tolerate high temperatures and salt winds. It is found in its native range from 200-600 m altitude (Santos Guerra, 1994).

Noting their ability to interbreed, it is likely that many pests and diseases of the date palm (P. dactylifera) could also attack P. canariensis. In the Mediterranean region, the red palm weevil Rhynchophorus ferrugineus (Coleoptera: Rhynchophoridae) has been recently introduced, and which has been observed attacking and severely damaging P. canariensis(Faleiro, 2006). It had already been noted as a pest of P. canariensis in Japan (Yoshitake et al., 2001). It is also reported that the giant palm weevil (Rhynchophorus palmarum) can kill recently transplanted palms or those which are injured, and the palm leaf skeletonizer (Homaledra sabalella) attacked the foliage (Gilman and Watson, 1994).

Fusarium wilt of P. canariensiscaused by Fusarium oxysporum f.sp.canariensiswas recorded for the first time in Australia first in South Australia (Summerell and Gunn, 2001) and later in Victoria (Summerell et al., 2006). Fusarium oxysporumhas also been seen on P. canariensis in Argentina, and it is spreading in Europe with a recent first record from Greece (Elena, 2005). Also attacking P. canariensis is the dwarf wilt Ceratocystis paradoxaobserved in Fujian, China, (Zhang and Lao, 2005), with a first report of bud rot Phytophthora palmivorain Italy (Pane et al., 2007), Ganoderma applanatum (Gilman and Watson, 1994), and a group phytoplasma causing lethal decline in Texas, USA (Harrison et al., 2002).

Environmental

• Amenity
• Ornamental

Human food and beverage

• Honey/honey flora

Ornamental

• Potted plant
• Propagation material

P. canariensis is probably only second in economic importance within the genus to the date palm, P. dactylifera, though can be separated by having a thicker trunk and longer fronds. P. dactylifera is, however, also an invasive species on several Pacific islands including Hawaii, Fiji and New Caledonia and possibly also the Galapagos (PIER, 2008), and P. reclinata is invasive in Bermuda (Kairo et al., 2003).

Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

No specific information has been located on best practices for controlling P. canariensis, although some control has been attempted in California and New Zealand. It is likely, however, that control would be relatively simple, by simply uprooting or hand pulling seedlings, and larger trees would be killed by felling at any height as they do not coppice.

29/02/08 Original text by:

Nick Pasiecznik, Consultant, France