Grafting Demonstration by Evelyn Weesjes. (Instead of a demonstration, diagrams were used to illustrate the various grafts.)

Earlier in this century rhododendron varieties were commercially grafted on R. ponticum, a vigorous, suckering rootstock which often overgrew the variety. Its bad reputation led to rooting from cuttings until recently when tissue culture took over. However, in Germany they graft on hardy rootstocks, including ‘Cunningham’s White’ to get more hardiness, drought resistance and the ability to grow in neutral or alkaline soils. This method increases the areas in which rhododendrons can be grown.

 But other than the reason mentioned, why graft? First, some varieties are difficult or impossible to root from cuttings. It can speed up the process of hybridizing, since grafted seedlings flower earlier. One could produce novelty plants, such as standards or multi-variety plants or graft a truss from a show.

 Grafting is usually done in February or March in a greenhouse using a side graft on forced rootstock and plunging the grafts in peat in a heated and covered bench. It is possible to graft at other times as long as the scion is not in soft new growth. Top or cleft grafting can be done in summer with no special equipment except to keep the grafts out of the sun. The rootstock could be ‘Cunningham’s White’ or ‘Anna Rose Whitney’. It is important to match the diameter of the scion with the rootstock so that the cambium layers just under the bark are in contact on both sides. A sharp grafting or utility knife is used to make the cuts. The scion must fit snugly into the rootstock and be tied with grafting tape, rubber budding strips or string. The grafts must be provided with a warm and moist environment and light. A simple method is to tie moist sphagnum around the graft and then place a plastic bag over the entire plant or just the scion and grafted area. The graft should heal in about 4 weeks. Diagrams were used to illustrate the different grafts and a few grafted plants were on display.

The earliest records from centuries BC described ‘paradise gardens’ in which shade and water were the major features. These gardens were laid out in strong linear lines and the trees used were fig or possibly date. Any flowers, if included, would be for medicinal purposes only.

Herbalists from ancient times studied plants for their medicinal value and later this led to the development of physic gardens usually associated with monasteries. Many of the plants described in these herbal books, once used medicinally, are now some of our common flowers. Hamish gave us quotations from a famous herbal book.

Early gardening was almost exclusively devoted to fruit, vegetable and medicinal plants. Gradually, as warring ceased and a wealthy class emerged, there developed the classic Islamic, Italian and French garden designs based on straight lines and symmetry borrowed from the ‘paradise gardens’. The English garden design differed in that it was based on the natural landscape with little formality.

Hamish mentioned some of the early plant collectors (with the exclusion of the Asian area ones) who travelled the world to bring back both economic or ornamental plants for the great gardens being developed. Tulips collected in Constantinople went to Clusius who settled in Holland, started a botanical garden and gave Holland the tulip industry. Similarly, potatoes collected in Peru went to Ireland and became a staple there. Britain had the rubber tree, collected in South America, sent to its India colony to start an industry. Later collectors would deluge Britain and the rest of Europe with an avalanche of ornamental plant introductions.

In his slide presentation, Hamish showed flowers and plants that each country contributed to our gardens. Masson who collected in South Africa introduced many plants which Hamish thinks should be more widely used here. However the plants from Australia and New Zealand are more a challenge to grow in our wetter climate. Hamish showed a wide range of plants from alpines to trees that have come to be planted in our gardens. So whence cometh our flowers? – from all around the world.