Black root rot, also called dead man’s fingers or Xylaria root rot, is occasionally observed on mature apple and cherry trees. Although trees of all ages can be infected, most trees that die from black root rot are at least 10 years old. Black root rot is caused by two species of the fungus Xylaria: X. mail and X. polymorpha, with the former more common in southern Appalachian states and the latter more common in eastern states. The disease …
What are burr knots?
Burr knots are root initials that develop above ground. Rootstocks are selected for their ability to produce roots, but some rootstocks try to produce roots above the ground. The severity of burr knot development differs depending on the variety and region. In several rootstock trials, trees in Virginia tended to produce more burr knots than trees in most other locations. Sometimes several burr knots will coalesce and partially girdle the tree. Burr knots are considered undesirable because they can be …
Armillaria Root Rot of Apple
Armillaria root rot, also known as shoestring root rot, is a soilborne disease that can affect several fruit crops. However, it is most common in the eastern United States on peach and apple trees. Its host range also includes numerous species of deciduous and evergreen trees, shrubs, and woody vines. The greatest prevalence of the disease is in orchards planted on newly cleared land in which the soils are sandy and well-drained. In these locations, pieces of wood invaded by …
How should I choose among dwarfing rootstocks for my apple orchard?
Choosing the best dwarfing rootstock for your orchard will depend on multiple factors. Probably one of the most important is the cultivar that will be propagated on the rootstock. Cultivars vary greatly in vigor, with some being very weak growing (‘Honeycrisp’) compared to others that are very vigorous (‘Cripps Pink’/’Pink Lady’). You should select the cultivar/rootstock combination that will give you the desired tree size for your desired tree density, support system, soil, and management system.
The disease sensitivity of …
I grafted 10 apple trees in the spring and only a few of the grafts started growing. Can I reuse the rootstocks? What kind of grafting can I do now?
If your bench grafts do not take but the rootstock is healthy and growing, you certainly can re-graft them in the same season.
► The earliest option is chip budding and is done as early as late spring to early summer.
1. Remove a “chip” of scion tissue which includes a healthy axillary bud.
2. Remove a chip of comparable size from a healthy section of rootstock.
3. Place the previously crafted chip of scion in the place where the …
What is the method to get apple trees to set fruit?
All varieties of apple trees require some cross-pollination for fruit set. Even though some varieties are listed as self-fruitful, they will set fruit more heavily and more regularly if they are cross-pollinated. For solid block plantings, select varieties such as spur-type ‘Winter Banana’, spur-type ‘Golden Delicious’, or flowering crabapples such as ‘Manchurian’ and ‘Snodrift’ for pollinizers. Place honeybees in apple orchards when the first blossoms open. For more information on managing fruit trees, see this article on Pollination of Tree …
What are some suggestions for growing apples successfully in Colorado?
Reliable varieties for this area are ‘Cox Orange’, ‘Red Delicious’, ‘Golden Delicious’, ‘McIntosh’, ‘Jonathan’, ‘Fameuse’, ‘Northwest Greening’, ‘Joyce’, ‘Wealthy’, ‘Lodi’, and ‘Haralson’. Select two different varieties for cross pollination and good fruit production. In most cases, planting semi-dwarf varieties rather than standard size trees will allow enough room for at least two different varieties in the landscape. For additional hints for growing apples successfully, see the Colorado PlantTalk script on Apples.…
I missed pruning a few dead branches in an apple tree. Can I remove them in the summer?
The best time to prune is early in the Spring before bud break. Dead or broken branches can be removed anytime, but keep other pruning to a minimum.…
Should I wait until after a frost to harvest my apples?
No, harvest apples before the temperature drops below about 28°F. That is canopy temperature and will not necessarily be reflected by the thermometer on your porch.…
I have a 'Gala' apple tree. Would planting a 'Granny Smith' tree in my yard serve as a pollinator for the other?
Yes, ‘Granny Smith” would be a good choice. If you can’t find a ‘Granny Smith’ tree, then a ‘Mollies Delicious’ would work well. To see a pollination chart for apple varieties, refer to this article on Pollination of Fruit Trees.…