No, it isn't a good practice. It is a useful way to re-wet the soil when it is so dry that the water is repelled by it, but it isn't a good way to water routinely.
First, we need to know what your soil is like. We usually recommend a free-draining soil, something that water runs through fairly easily. In this way, the roots will never rot. The soil needs to hold enough moisture so that the roots don't dry out, but not be soggy.
If your soil stays soggy, the trees may get root rot or other root problems. Too much organic material (peat moss, etc) will keep the soil too wet. Try this.... take a wooden chopstick and stick it into the soil, all the way down to the bottom of the pot. Leave it there between waterings. When you pull it out, you should check it to see that the soil in the lower part of the pot is just moist... not too wet. If the soil is wet, and soil sticks to the chopstick, don't water yet.
If you find that your soil does dry out all right, then you need to start watering from the top. A gentle "rain" of water, enough so that the soil is nicely moistened, followed by another "rain" in a few minutes, enough so that water is running out of the holes in the pot. As the water runs through the soil, it pulls oxygen behind it, and refreshs the atmosphere inside of the pot. It flushes salts and carbon (dioxide? Monoxide? I forget which) and cleanses the soil.
Always fertilize the same way... and make sure that the soil is moist before giving fertilizer.
If you don't do this, you may risk accumulating salts in your pots. Salts will slowly kill your trees. They won't be able to absorb nutrients.
You may have to help us understand your climate, since we don't have a lot of members living in your area.
Joanie