Question: I have a lemon tree that we planted three years ago. It is not growing well. It is next to an adult California pepper tree. (10 feet away) I would like to dig it out and transfer it. Are there any concerns or special care doing this?
Answer: Ten feet away from another tree is likely too close and the California pepper tree is known for its competitive roots so I am glad you are thinking of moving the lemon. One of the first things to consider when planting is the mature size of the tree so there will be plenty of room between the tree and anything else. There are some basic guidelines when transplanting. Moisten the area where you intend to plant a few days prior to digging to make it easier. Dig the planting hole twice as wide but only as deep as the root ball. The edges of the excavated area should be rough and sloping. A shallow hole prevents the tree from sinking and burying the trunk. One of the most common mistakes is planting too deep. Since your tree has already been in the ground for three years the roots will be growing. You may have to prune some of them back to extract it from the original planting hole. This is a good opportunity to check the root system for matted or circling roots. If needed you can cut and separate roots that are circling or heading in the wrong direction. Place the tree carefully into the planting hole. Remove just enough soil from the top of the root ball to expose the root collar, which should be level or slightly above the surrounding soil. The root collar is where the trunk flares out just above where the roots begin.
Backfill the planting hole with native soil. There is no need to add amendments. Studies show there is no advantage to mixing compost or other organic amendment into the soil. If hand watering or using bubbler irrigation, form a berm just outside the root ball to create an irrigation well. Apply water within this area. As the tree grows, expand the well. If using a drip system, use two or three emitters to wet this same area. Increase the number of emitters and spread them out to stay in line with the edge of the crown as the tree grows. Set your irrigation schedule to supply water every seven to 10 days in the summer and make sure the water reaches a depth of 36 inches. Apply a two to four inch layer of mulch to the entire tilled area. Keep mulch away from the trunk.
Peter L. Warren is the urban horticulture agent for the Pima County Cooperative Extension and the University of Arizona.  Questions may be emailed to tucsongardensage@gmail.com.
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