What causes my apple and pear trees to look like they have been burned with a torch?

A disease called fire blight, caused by a bacterium (Erwinia amylovora), has these symptoms. The causal bacteria are spread by wind-blown rain and insects. Fire blight is difficult to control in highly susceptible varieties. Avoid excessive nitrogen fertilizer. The blighted shoots and blossoms can be pruned out as they appear if you sanitize the pruning shears by dipping them in a 10 percent bleach solution or 70% isopropyl alcohol (rubbing alcohol) between cuts. Otherwise, prune the blighted shoots …

How do I find out what variety my apple tree it is? Can my local Extension office tell me ?

It is difficult to identify apple varieties unless your variety is a very common one. There are more than 10,000 named apple varieties in the world today. Sometimes we may be able to tell what “type” of apple it is (e.g., Jonathan type, Delicious type). When planting fruit in the landscape, it is important to create a plan showing where different varieties are planted. Put the plan in a notebook and a copy in the garage or planting shed.…

When is the proper time to thin fruit on apple, pear, and peach trees?

Apples and pears have three periods when some immature fruit drops naturally from the tree. The June drop (Zones 6 and 7) is the last one, and many growers feel that thinning should follow this drop. However, if a heavy bloom has coincided with good weather so that bees worked the blooms, the chances are that relatively few fruit will drop from the tree. In this instance, heavy thinning is required. The earlier the fruit are thinned, the greater the …

How long can I store fresh apples?

Late-maturing varieties of apples will store for use throughout the winter if the fruit is hard, mature, and in perfect condition. Apples picked too green (unripe) are subject to a number of storage disorders, such as scald and bitter pit; if picked beyond maturity, they quickly become overripe in storage. Cool fruit as quickly as possible after harvest for best results. For most varieties of apples, the optimal storage temperature is 30° to 32°F with a 90% relative humidity. Higher …

How can I control insects and diseases on my apple tree?

Homeowners are often surprised at the damage pests can do to apples. It is not easy to grow apples as pretty as those seen in the grocery store. Several diseases and insects can damage apple trees. Besides spraying pesticides, other things can be done to reduce pest damage, but it is very difficult to grow quality apples without some kind of pesticide application schedule. Rake and destroy leaves in the fall to reduce damage from diseases that overwinter in infected …

What is the best way to tell when apples and pears are ripe?

Harvest time varies with individual tastes and locality. One may consider a fruit ripe, while another individual believes it is immature. However, fruit picked too soon does not store well and does not develop full flavor. Probably the most reliable index is the number of days after bloom: Red Delicious takes 135 to 155 days from full bloom to harvest, whereas Granny Smith takes 170 to 180 days from full bloom to harvest. Other factors to consider include seed maturity; …

I bought some Whitney crab apples for pickling. I ate one prior, and it was fine. After I did the pickling, I cut a few open and there was a brown ring around the core of the seeds. Do you know what might have caused this?

The brown flesh around the core may have been caused by a fungus such as Alternaria sp.that entered through the calyx early in the fruit’s development. The condition, called moldy core, often cannot be detected until the fruit is harvested and cut. Here is a note about moldy core from the University of Massachusetts Apple Team:
“Moldy Core: This disease causes a rot with visible fungal growth in the seed cavity and core of some apple cultivars, particularly Delicious …

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.…