Experts tackle readers’ garden questions.
Q: We planted a valley oak in our front lawn area to provide shade. The Tree Foundation counseled us what to plant. The tree was planted a few years ago and is now approximately 15 feet tall. My concern is that there is approximately a 3-foot growth on top with very few branches. It appears to have been topped and has significant growth at the top-most end, which now causes the top portion to lean.
I had a similar situation where I topped a corkscrew oak. The result was that the tree developed a second main stem. Please advise the best way to rectify this problem.
Nancy Diehl, Carmichael
Master gardener Annie Kempees: The photo of the tree you sent shows me a very young valley oak (Quercus lobata) in good health with normal branching patterns.
Young trees are tall and gangly with slightly bending pole-like growth during the first 10 to 30 years of their lives. As the tree grows and matures, the top will straighten up and the branches will grow outward.
Fortunately, it is unlikely that the tree was topped. Topping seriously injures trees, disfigures them and forces the growth of many vigorous upright shoots that are weakly attached.
Properly trained trees are easier to maintain and generally will live longer than untrained trees. Key points to training are to:
▪ Remove broken, diseased, dying or dead branches.
▪ Select a central upright leader.
▪ Select the lowest permanent (or scaffold) branch. This branch is the lowest branch that will remain on the tree through its life and is determined by the use and location of the tree. For example, the lowest permanent branch over a sidewalk might be 8 feet up, while over a street it might be 14 feet.
▪ Keep some temporary branches below the lowest permanent branch.
You can learn more about tree care with a series of cards available from the UC Cooperative Extension. To order the series of seven cards, send a self-addressed, stamped business-size envelope (with 71 cents postage) to: UC Cooperative Extension, Tree Cards, 4145 Branch Center Drive, Sacramento, CA 95827.
Annie Kempees is a UC Cooperative Extension master gardener for Sacramento County.
Questions are answered by master gardeners at the UC Cooperative Extension services in Sacramento and Placer counties. Send questions to Garden Detective, P.O. Box 15779, Sacramento, CA 95852. Send email to firstname.lastname@example.org. Please put “Garden Detective” in the subject field and include your postal address. To contact UC Extension directly, call:
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