Answer: Dogwood (Cornus florida) trees do best in a location with morning sun or bright dappled light all day and good air circulation. The soil should be organic and humusy, acidic, and evenly moist yet well drained. (This tree will not tolerate soil that is overly wet or overly dry.) The root area should be mulched year round with two to three inches of organic mulch spread out in a flat layer. Keep the mulch several inches away from the bark of the tree. The soil should be kept evenly moist like a wrung out sponge, not saturated and not sopping wet. Top dress once or twice a year with good quality compost, fertilize lightly in spring with a slow release fertilizer for acid loving plants such as Hollytone. Do not overfertilize, this tree is not a heavy feeder.
There are several serious disease problems with these trees, if the diseases are prevalent in your local area it may not be the best choice of tree to plant. Also, if you have lost a tree to disease, do not replant in the same spot.
Ornamental cherries do best in full sun and soil that is well drained. They are more drought tolerant than dogwoods but would still need careful watering for the first year or two. To know if you need to water, dig into the soil with your finger. If it is still damp, do not water yet. When you do water, water slowly and thoroughly so it soaks down to the deepest roots. After watering, wait a few hours and then dig down and see how far it actually went; sometimes this can be surprising. It is better to water deeply less often than to water lightly every day.
Cherries also have some serious potential problems such as borers, so they need to be kept growing vigorously to try to ward them off. You would fertilize in the spring with a granular or slow release fertilizer such as 10-10-10 per the label directions and top dress with compost once or twice a year. Maintain a mulch layer as above.
Correct planting procedure is also important. The best time to plant these is in very early spring. A midsummer planting is going to stress them and may send them into shock due to the hot weather.
They should be planted at the same depth as they grew before, no deeper. Dogwoods are especially sensitive to being planted too deeply.
You also need to make sure there are no encircling roots at planting, if you find those you need to cut them or unwind them and direct them outward.
With ball and burlap trees you need to remove all the burlap and twine, and if they have been dipped in a clay solution so the rootball is hard on the outside, that needs to be scratched and loosened as well.
Your local professionally trained nurseryman and/or county extension should be able to help you determine if you have a suitable location for these trees and may be able to help you troubleshoot what has happened in the past so you can take corrective steps. I hope this helps.
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