If you are planning a new home orchard or thinking of replacing aging fruit trees in an existing orchard, you might want to think about dwarf apples, said University of Illinois Extension horticulture educator Richard Hentschel.
There are several different kinds of fruit trees, such as apple, cherry, peach, pear, plum, and apricots. In northern Illinois, apple is the main fruit tree grown in back yards.
Dwarf apple trees are naturally smaller than their full-sized siblings and are much easier to train, prune, and maintain than a full-sized fruit tree. They are also perfect for home orchards where space may be limited.
"Fruit trees are dwarf because they are naturally that way or because fruit tree growers graft or bud them to a dwarfing rootstock, limiting the size of your future fruit tree," Hentschel said. "If they are naturally dwarf, they will be listed as a 'spur-type' tree. There are many examples of spurs available to us — empire, red and yellow delicious, Macintosh, Rome, Winesap, and early blaze are a few."
Other dwarf trees are grown on a dwarfing rootstock, often crabapple. The smallest fruit trees will be spur types grafted or budded on a dwarfing root stock.
The catalogs will list a mature size that is considerably small than the full-sized version, but the size of your mature dwarf tree is up to you. If you start to train too late, or do not prune correctly, the tree will be larger than you wanted but still smaller than a full sized tree.
Another important consideration when selecting fruit trees is pollination. Fruit tree catalogs will suggest which apple varieties will be the best pollinators for the varieties you wish to grow.
"It is critical that you have two different varieties blooming at the same time to get good pollination and a strong fruit set," said Hentschel. This is because most apples are "self- unfruitful," meaning that flowers cannot be pollinated by other flowers on the same tree or by flowers from another tree of the same variety.
Sometimes a catalog will indicate that an apple variety is in a pollination group. If it is grown with another variety in the same group, cross pollination will occur.
Pollen from the flowering crabapple can also pollinate fruiting apple trees. If you or a neighbor have a flowering crabapple that blooms at the same time as your apples, you do not have to plant a second apple variety for pollination purpose. You can use the space for another kind of fruit tree.
The placement of the home orchard can make a big difference in how well the fruit trees grow and perform. Soil quality is a major consideration.
"Fruit trees are no different than other trees or shrubs in your landscape, they need good soil drainage," said Hentschel. "Placing the home orchard where water will drain away quickly after a rain will help ensure that the roots will have the needed soil oxygen to continue to supply both the moisture and nutrients needed to the canopy to support continued growth of the foliage and filling of the fruits. If the soil oxygen is displaced for an extended period of time, the roots are unable to move the moisture and nutrients up into the tree. Soils that remain too wet will also promote root loss through decay, putting further stress on the fruit tree."
Proper air drainage is also important. Little can be done about a hard frost or light freeze, but the risk can be reduced by planting the trees in the best possible locations in the yard. Cold air settles in low areas, so home orchardists can prevent damage to the flower buds from late spring frosts by placing the trees on a slope or at the highest point in the landscape.
"Home orchardists can delay the spring growth of fruit trees by mulching the soil late in the fall or early winter, well after we have had cold weather set in and hopefully after the ground is very cold or even frozen," said Hentschel. "This activity will keep the ground frozen and the root system cold and delay the fruit tree from breaking dormancy even by a few days, helping us get past the chance of that late frost. Another activity can be protecting those flower buds from cold air by placing a temporary wind break up to break up or slow the cold wind."