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May Questions and Answers

© Keith Muraoka

Q. I live in a five-year old subdivision. There are two trees in our front yard that are thriving. One was planted by the original landscaper in the middle of the lawn. The other is a volunteer cottonwood that has located itself perfectly near the fence. Both are putting out prodigious roots near the ground surface. The planted tree is a sweet gum -- it has furry (not spiky) seed balls about the size of a golf ball. Its roots are headed for the sidewalk and will threaten to raise it in a few short years. The cottonwood also is putting out roots along the surface, which complicates our plans to "finish" the area near the tree with pavers and lavender. What consequence will ensue if I just hack off the threatening roots? Will the tree weaken and die? Will it become unstable?

A. I hate to give you bad news, but I would remove those trees before they really start to grow and break up your sidewalk or get into water/sewer lines. Both the cottonwood and liquidamber (sweet gum) are notorious for invasive, damaging roots. You may have a little more luck with the sweet gum since it is planted in the middle of your lawn. If it is at least 20 feet away from the sidewalk, you may be OK. I wouldn'y cut any surface roots because this will significantly weaken root systems. I wish I would have removed the tallow tree that the city planted in the parking strip. Its roots have not only cracked the sidewalk, but pretty near ruined the paving stones I installed. You might consider crepe myrtles as alternate plantings.

Q. This is a problem that I run into periodically. I have a dwarf orange tree in my backyard and, this year, I had a bumper crop. Unfortunately, I had a bumper crop of not-very-sweet oranges. Did I need to fertilize to get them to taste better?

A. You didn't do anything wrong! Citrus sweetness is directly related to the heat of the previous summer. That's why oranges grow so well in Florida and southern California. If you remember, last summer wasn't very hot except for that record-breaking single day. The acid/sugar ratio in citrus is determined by summer heat and there is no way we can do anything about it. If this happens again, use your oranges for juice instead of eating fresh, and add your own sugar.

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