Edible Landscaping: Apples – Part 1


Apples would be the first fruit mentioned when the subject of fruit trees is raised, so we would be amiss not to start with them.

There are excellent orchards in Loudoun that are sources of a wide variety of apples, so we continue to PYO at these orchards frequently, even buying excess that we make into applesauce. As you will see, the list of pests and diseases that can potentially attack an apple tree or its fruit is quite extensive, requiring long hours of studying and possibly numerous sprayings throughout the growing season, so leaving apple growing to the local orchards might be the approach to take. Don’t worry, there are many other fruits and nuts to pick from, so don’t be dissuaded right off the bat.

Let’s take a look at our criteria (and add a couple) to see how apples may (or may not) be a factor in our landscape;

Disease resistance: In the Mid Atlantic, there are many diseases which can affect apple trees and their fruit, which can be reviewed at the Mid-Atlantic Orchard Monitoring Guide and at the WVU Index of Fruit Diseases. While these lists are long, some of the more troublesome ones in this area tend to be Apple Scab, Cedar Apple Rust, Fireblight, and Powdery Mildew. The good news is, there are varieties that are resistant in varying degrees to these diseases. To simplify matters, let’s take a look at those cultivars that are [1];

VR = Very Resistant

R = Resistant

MR = Moderately Resistant

Variety Resistance ratings Tree growth habit Comments
Apple scab Cedar apple rust Fire blight Powdery mildew
Dayton VR MR R MR Semi-vigorous, spreading Sometimes prone to bitter pit
Enterprise VR R R MR Moderate to high vigor Best flavor after Very resistant month in storage
Freedom VR R R R Vigorous, spreading Good pollinator for Liberty
Jonafree VR MR MR MR Moderately vigorous, may have some bare wood Similar to Jonathan in appearance, not prone to Jonathan spot
Liberty VR VR R R Vigorous, spreading One of the best disease-resistant cultivars, a McIntosh-like fruit. Susceptible to European Red Mite and San Jose Scale
Nova Easygro VR VR R R Moderately vigorous, spreading Developed in Nova Scotia
Novamac VR VR R MR Vigorous, upright and spreading Susceptible to preharvest drop, developed in Nova Scotia
Priscilla VR VR R MR Moderately vigorous, thin branched Fruit cracking when overmature
Pristine VR R MR R Moderately vigorous, spreading, wide crotch angles Less susceptible to bruising than Lodi
Redfree VR VR MR MR Vigorous, spreading,wide crotch angles Some bare wood on limbs
Trent VR R MR R Moderately vigorous, slightly upright Susceptible to bitter-pit, from Ontario
William’s Pride VR VR R R Vigorous, spreading, large tree size Not recommended on a MM. 111 rootstock due to bitter-pit, prone to water core

Pollination: Apples require pollination from another cultivar that flowers during the same time (crabapples can also be used as a pollinator). Semi-dwarf trees should be within 50 feet of their pollinator; dwarf trees within 20 feet.

Cultivar Pollination time Typical

harvest time

Storage

time

Fruit characteristic
Pristine early late July 1.5 months Medium-large; yellow

with blush; slightly tart

Williams’ Pride early/mid late July 1.5 months Medium-large size; red fruit;

softens quickly; spicy,

well-balanced flavor

Redfree early/mid early Aug 1 month Medium size; bright

red; well-balanced flavor

Jonafree early/mid early Sept 2 months Similar to Jonathan
Liberty early/mid early Sept 5 months Small-medium size;

red over green color;

McIntosh-type of fruit;

tart with coarse texture

Enterprise mid/late mid Oct 6 months Large; bright red;

spicy and juicy

Trent mid/late late Oct 6 months Medium-Large; Red blushed

over light green, sub-acid

,less than McIntosh

Fruiting Schedule: See above chart for times.

Harvest: To ensure maximum storage life, apples should be harvested when mature but not yet fully ripe or overripe. If harvested before they have matured, apples will have poor eating quality, will be more susceptible to storage disorders such as scald, cork spot, and bitter pit, and may not ripen properly. [2]

Storage: See above chart for storage duration. An apple continues to live and respire after it is picked. Although respiration cannot be halted completely, the objective of postharvest cooling is to slow the process and thus increase storage life. Even if apples are to be stored for only a short period, it is still very important that the field heat be removed from them as soon as possible. Apples respire and degrade twice as fast at 40 F as at 32 F. At 60 F they will respire and degrade more than six times faster. The optimum storage temperature for apples depends on the variety, but all are within the range from 30 to 40 F. [2] Ventilation keeps ethylene and carbon dioxide from building up to damaging levels. While refrigerators are generally used by commercial orchards/wholesalers, backyard orchardists can also take advantage of root cellars and barrels in garages for late season apples, as long as humidity levels can be maintained.[3][4]

Size: The size is predominantly determined by the rootstock. Virtually all commercially available apples (with some exceptions) use a rootstock to impart size and disease resistance qualities to a grafted variety. Some common rootstocks are shown below along with their sizing tendencies. Note: Standard size apple trees are very difficult to manage, due to the need to prune, harvest, and inspect. Semi-dwarf trees are much more manageable, and dwarf trees are by far the easiest.

There are many other rootstocks available, and it helps to know which rootstock a nursery is offering with a tree (though often times that information is not at the fingertips of the person answering the phone. I normally discover the rootstock on the tag when the tree arrives.)

Growing Techniques: These range from the ordinary freestanding to espalier, trellis, and spindle (advanced trellis) techniques. Most beginner backyard growers default to the usual freestanding central leader, which is fine for simple purposes. Espalier produces a decorative look that also provides support for dwarf varieties. Trellising gives easy access to a number of dwarf apple trees that can be space efficient. Spindle systems are by far the most productive in terms of space, productivity, and time to full bearing [5][6].

Technique Density per acre Spacing
Freestanding 132-290 12’x 20′
Trellis 605 6’x 12′
Slender Axis 908 4’x 12′
Tall Spindle 1320 3’x 11′
Super Spindle 2178 2’x 10′
Tall Spindle

Tall Spindle

Super Spindle

Super Spindle

Part 2 will cover pests and miscellaneous.

— Will Stewart

References:

1. University of Missouri Extenstion Office, Apple Cultivars, http://extension.missouri.edu/publications/DisplayPub.aspx?P=G6022

2. NC State Extension Service, Postharvest Cooling and Handling of Apples, http://www.bae.ncsu.edu/programs/extension/publicat/postharv/ag-413-1/index.html

3. Maryland Extension Office, Root Cellars, http://extension.umd.edu/publications/pdfs/fs803.pdf

4. Purdue Extension Office, Storing Fruits and Vegetables at Home, http://www.hort.purdue.edu/ext/ho-125.pdf

5. Terence L. Robinson, Cornell Department of Horticultural Science, Modern Apple Training Systems, http://orchard.uvm.edu/uvmapple/hort/ROBINSON_ModernAppleTrainingSystemsVTFGAFeb2006.PDF

6. Michael L. Parker and C. Richard Unrath, Department of Horticultural Science, North Carolina State University, High Density Apple Orchard Management, http://www.ces.ncsu.edu/depts/hort/hil/pdf/ag-581.pdf

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