Native plant Knowledge Base
FNPS staff members periodically write about topics of interest to native plant gardeners on the Colorado Plateau. Check back frequently for new postings.
Things You Should Consider before Buying an Apple Tree...
Choosing a Rootstock. Flagstaff Native Plant and Seed offers different disease resistant apples on two different types of rootstocks. The dwarfing rootstock varieties we carry will give you an 8-12 foot tree, while the semi-dwarfs will give you a 10-17 foot tree. We do not carry standard apple trees, which get well beyond 20 feet.
Your choice of rootstock is perhaps the most dominant and critical factor influencing the type of tree you’ll end up with. Dwarfing rootstocks control overall tree size by reducing shoot growth in the scion (upper, bearing part of the tree). Size-controlling rootstocks, rather than exclusively pruning, are an easier, more effective way to control a tree’s height and keep it within its allotted space. Rootstocks also help control disease/pest resistance, and fruiting efficiency.
The possibilities and advantages of growing dwarf apples for the home gardener abound. By keeping trees to a height of 8-12 feet at maturity, all the necessary tasks can be performed from the ground or on short ladders — observation and enjoyment, pruning/training, spraying, thinning and picking. By growing smaller trees, home gardeners can get more out of a limited space.
There are several drawbacks to dwarfing rootstocks. One disadvantage is a smaller root systems, resulting in poorer anchoring. Dwarf trees with heavy fruit loads may need staking or other support to keep from falling over. Thinning heavy fruit loads can lessen this problem and will increase the size of remaining fruit. Another disadvantage to dwarf fruit trees is that with a smaller root system, they are more drought susceptible. Drought stressed trees can be more prone to disease & insect attack. Care should be taken to fertilize and water dwarf trees more frequently than standard-sized trees to encourage vigorous growth. Similarly, flowers and fruits should be removed for the first 1-3 years, until the tree has established itself. Fruit set on a young tree competes for available nutrients and reduces vegetative vigor.
Semi-dwarfs are much better anchored and more drought tolerant. They can be kept small for ease of harvest and accommodation into smaller spaces by summer pruning. Pruning in summer has a naturally dwarfing effect on trees. Summer pruning avoids the stimulating effect that dormant pruning has on trees. With annual pruning when a tree is young, trees can be maintained as short as can be reached from the ground with arm outstretched.
Planting and Fertility. When preparing the planting hole, make it slightly wider and deeper than the spread-out roots. Although conventional wisdom dictates that fertilizer shouldn’t be added to the planting hole, that doesn’t always apply to the backyard gardener. However, don’t add more than 10-20% stabilized, finished compost mixed in with the soil that comes out of the planting hole. This could cause a “pot effect” in the hole, and the roots will be reluctant to extend into the surrounding soil. To encourage roots to lengthen and deepen, work the soil outside the tree’s drip line with cover crops and soil amendments, such as finished compost. Avoid low lying areas on your property, as things planted in these areas are more susceptible to frost damage. Leave the graft union of the tree 2-3 inches above the ground.
Pollination. Although some apple varieties set fruit crops without cross-pollination from another variety, most set better with a pollinizer. Varieties that bloom about the same time as other apples can be used as a pollinizer (a plant that is a source of pollen). Crabapple varieties also can be used as a pollen source. In situations where a solitary apple tree is planted, branches of open fresh blossoms or another apple or crabapple pollinating variety can be placed in buckets of water and hung in the tree.
Watering. For maximum tree and fruit growth, water needs must be satisfied from pre-bloom to harvest. Watering frequency during the growing season can vary from 14 to 28 days, depending on the age of the tree, climate, and soil type. Young plants have small root systems and require close attention. Fruit trees respond to deep watering; saturate the soil to a depth of 3-4 feet. Build basins to extend past the tree’s drip line. Mulches will help conserve moisture. Use an organic mulch, such as compost, well rotted manure, straw, or bark chips, 6 inches thick; keep the mulch away from the tree trunk. Apples enjoy well drained soil. A good test for this is to fill a five gallon hole with water. If it drains within 24 hours, you have decent drainage.
Pruning and Training. The objective in training the young apple tree is to develop a strong framework of fruiting branches that admit an abundance of sunlight and is easily accessible for fruit thinning and picking. Pruning is continued as the tree matures to remove excessive growth, get rid of broken or diseased branches, and maintain tree shape and size. Then, for the mature tree, pruning is used to stimulate production of new and strong fruiting wood that continues to produce good fruit size, color, and quantity. If you are serious about pruning/training an apple tree, do some research to make sure you understand the different concepts and styles. Pruning at different times of the year has different effects on growth.
Thinning. Thinning the fruits off your fruit trees has many advantages. It reduces limbs breakage, increases fruit size, color, and quality, stimulates floral initiation for next year’s crop, and is a good opportunity to pay attention to your tree’s overall condition and health.
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400 E. Butler Avenue •
Flagstaff, AZ, 86001
• 928.773.9406
info@nativeplantandseed.com
