Top of the N.Z. plant charts

Press, 26 June 1987, Page 14

Top of the N.Z. plant charts

Oardener’s W DIARY

Derrick Rooney

Aesculus is a genus of mostly large trees which include the familiar horse chestnut, a feature of the Avon riverbank plantings in Christchurch. In North America, too, the horse chestnut is widely grown as an ornamental tree of parks and other public places, but there are also native North American species of Aesculus, which are known there as "buckeyes.” x Most of these species are, like the horse chestnut itself, far too big for most private gardens. However, there are in North America several lesser known small species of buckeye which would not be out of' scale in gardens. One of these, known as the “red buckeye,” is Aesculus pavia, which is sometimes available in New Zealand. This is offered by a large wholesale nursery grafted on what looks like horsechestnut stock; I don’t. know what effect this might have on its growth rate, but on its own roots the red buckeye grows about four metres tall after quite a few years. The red flowers appear in late spring or early summer, and the leaves which follow them have a sort of coarse opulence. Also red is the “flame buckeye,” Aesculus spendens, which is a little less vigorous, a little more refined.

I was lucky enough to secure a plant of this recently. It has been described in Britain as the most elegant member of the genus, and in the United States it has been included in lists of the top 10 American shrubs. The leaves are glossy, and quite handsome, and the flowers dangle in long panicles. And now for something completely different: the top New Zealand shrubs. The Nurserymen’s Association recently asked a panel of-garden-centre operators to - list■ the 12

best-selling native genera. No prizes for guessing No. 1: Pittosporum. However, there were. one or two surprises among the other 11, which were, in voting order: Pseudopanax Phormium Hebe Coprosma Leptospermum Sophora Cyathea Clianthus Metrosideros Hoheria Cordyline The association’s journal, "Commercial Horticulture,” notes that the surprising aspect of this selection is that the three top-ranking genera are all grown for their foliage — not their flowers. The panel was also asked to list the most popular cultivars, hybrids, or species in each genus. Interestingly, despite the extensive selection and hybridising that has gone on with native plants in recent years, this list is dominated by “old favourites,” varieties which have been available for 10 years or more. The selections include: • Pittosporum “James Stirling,” "Silver Sheen,” “Sunburst,” eugenoides. • Pseudopanax “Gold Splash,” lessonli hybrids, “Cyril Watson.” • Phormium “Dazzler,” "Yellow Wave,” “Guardsman.” . • Hebe speclosa, diosmifolia, “inspiration.” • Coprosma “Kiwi Gold,” repens "Variegata,” kirkii, prostrata.

• Leptospermum nana types, “Red Damask,” “Rosy Morn.”

A notable omission from this list is the variegated form of the lemonwood (Pittosporum

eugenoides), a long-time favourite of many gardeners. Interestingly, this is among the plants listed by the retailers in reply to the next question: What native plants are regularly in short supply? Among. the other natives that they can’t get enough of, the retailers listed: ' Knightia excelsa (the rewarewa) Pomaderris komeraho Ground fems Brachyglottis purpurea Coprosma repens, varieties Hebe hulkeana Myosotidium (Chatham Island forget-me-not) Phormium “Dazzler” Sophora tetraptera And the sales figures? These seem to indicate that most New Zealand gardeners still go for exotics. The percentage of natives in tree and shrub sales, varied from a high of 30 per cent in one North v Island garden centre to 10 per cent or less in a South Island outlet. A Timaru retailer commented: “We used to specialise in native plants, but found, that our enthusiasm and dedication just did not pay. We had to diversify into other material to cater for people’s needs in our area.”

Think about that next time you get annoyed because the local garden centre doesn’t have the native plants you want.