Dwarf fruit trees, which have been grown for hundreds of years in Europe, are becoming more and more popular in this country today.
Since the trees are small in size, they are easier to prune and spray, and the home gardener can grow several varieties of apples, pears, peaches, and plums on a plot of land 40’ x 60’ feet.
Dwarf trees also bear at an early age, and when mature, they produce about a bushel of fruit per tree.
Growing Dwarf Apple And Pear Trees
Dwarf apple and pear trees have been grown for hundreds of years by grafting or budding them on dwarfing rootstocks.
Apples dwarfing rootstocks were originally known as Paradise, Jaune de Metz, Doucin, and others, but after testing them for trueness to type at the Mailing Research Station in England about 30 years ago, they were given Mailing numbers.
Mailing IX is the most dwarfing type, while Mailing VII is semi-dwarfing. Therefore, standard varieties of apples grafted on these dwarfing rootstocks will come into bearing earlier and produce larger fruits than varieties grafted on standard rootstocks.
Pears Dwarfed By Grafting
Pears are dwarfed by grafting them on quince rootstocks. We have used cotoneaster rootstocks for pears, though they do not transplant easily.
By budding cotoneaster on hawthorn and April 1956, then budding the cotoneaster with pear, we get a tree that can be transplanted more readily. Seckel pears dwarfed in this manner produced several dozen fruits on trees, less than 5’ feet tall, the fifth year.
Production of Dwarf And Plum Trees
The production of dwarf peach and plum trees is relatively new. Wide varieties can be dwarfed by budding them on Western sand cherry (Prunus besseyi) or the Nanking cherry (Prunus tomentosa).
Here at the Bussey Institution, we have been using seedlings of the Nanking cherry as a dwarfing stock for peaches and plums.
The dwarf peach trees produce flowers and a few fruits when they are two years old. When six to eight years old, they will bear about 100 large fruits on a tree that is only 6’ or 7’ feet tall. The dwarf peach trees on Nanking cherry rootstocks are now available from nurserymen.
Other Methods Of Inducing Earlier Fruiting
Girdling
Other methods of inducing earlier fruiting include girdling a narrow bark ring on a tree’s trunk or branches. This ancient technique is a standard practice in vineyards to stimulate grape production but is not often used on fruit trees because of the danger of killing or injuring the tree.
Bark Inversion
The same result, without the hazards, can be obtained by inverting a bark ring on the tree’s trunk. We have been using this method of dwarfing apple trees for the past six years.
A ring of bark about 2″ inches long is removed from the tree, turned upside down, and bound tightly with a rubber band. The inverted bark is soon united with the wood, and the band can be removed after 10 days.
The best results are obtained on apple trees 3 to 5 years old. The effect is not permanent, but after several years the operation can be repeated.
Bark inversion can also be used on dwarf apple trees, which are making too much growth, as sometimes happens if they are dwarfed by using a dwarfing interlock instead of a dwarfing rootstock.
The bark inversion method is unsuitable for dwarfing peaches, plums, or cherries because of the “bleeding” of the cut stems.
What Happens When A Standard Variety Of Apples Or Pears Is Dwarfed?
Experiments with radioactive tracers show that the nutrients made in the leaves do not readily pass through the dwarfing stock or inverted ring of bark.
The roots do not get enough food to ensure vigorous growth and the carbohydrates retained at the top of the tree promote larger fruits.
These experiments do little more than confirm what the famous English horticulturist, Thomas Andrew Knight, had discovered nearly 150 years ago.
Standard Growing Conditions
Growing conditions for these trees are the same as for standards. They require full sun and rich, well-drained soil.
Feed in the early spring and again in the early summer, but avoid late summer feeding, which stimulates late growth that does not have enough time to ripen before winter.
The soil around dwarf trees should be kept cultivated, but apple trees may be grown in sod after maturity. The grass should be cut regularly, and the trees should be given extra fertilizer.
Care For Peaches
Peaches require little care, but borers are often a problem. We have found a simple control method with a single treatment each year.
A greasy mixture of one part of 50% percent chlordane is mixed with nine parts of heavy lubrication grease.
An inch of soil is pulled away from the surface, and the mixture is smeared on the base of the trunk to a height of about a foot. In the northern states, this should be applied in late June.
Remember that the dwarfs, like their larger counterparts, usually require several varieties to ensure cross-pollination.
Most peaches are self-fertile. Planting several varieties makes it possible to have kinds that ripen over a longer season.
Ancient Art Of Propagating
The ancient art of propagating species of trees and shrubs by budding or grafting them on other species or genera has also been used to dwarf or modify the growth habits of certain ornamental plants.
Producing Small Trees
The Japanese flowering quince on apple rootstocks, the flowering almond budded on the Nanking cherry, and the cotoneaster on hawthorn (Crataegus) rootstock will all produce small trees instead of spreading bushes.
Tree forms of common lilac can be produced by grafting them on the Japanese tree lilac (Syringa amurensis japonica). The red maple is dwarfed by grafting it on the silver maple.
Small Orchard Greenhouse
Bussey Institution has a small orchard adjacent to the greenhouse, which includes dwarf apples, pears, apricots, plums, and peaches.
Those interested are welcome to visit this planting to study more closely these various kinds of popular fruits dwarfed to accommodate the small homeowner with limited area, time, and energy to devote to growing fruits.
44659 by Dr. Karl Sax