Q: I think I've got the only grapevine in Napa that will not make a grape!
We have a red seedless table grape plant that will not produce any grapes. The plant is about 5 years old and I'm ready to take it out. It's a beautiful plant. I use the leaves in cooking but would really like a few grapes.
I would be grateful for any advice.
– Jim Wisinger, Napa
A: Sometimes grapes that get too much water produce a lot of growth but no fruit, says UC Master Gardener Bill Pierce. They are deep-rooted plants and, when established, may need water only every two weeks during the dry season.
Is your vine planted near a lawn or other cultivated area that gets frequent irrigation? If so, the plant's lateral roots may be soaking up lots of water.
"My grapes grow under these conditions, so they are not irrigated and they pick up sufficient water from the adjacent vegetable garden," Pierce said.
Are you cane or spur pruning this vine? Table grapes are pruned during the dormant season with either the spur or cane method, depending on the variety of grape. Poor pruning techniques could result in lack of fruit.
For a copy of Garden Notes No. 108, "Grape Vine Pruning," please send a self-addressed stamped, business-size envelope to: Garden Notes No. 108, UC Cooperative Extension, 4145 Branch Center Drive, Sacramento, CA 95827.
Q: We are concerned about a native oak tree located on the Chicken Ranch Slough Drainage/Utility Easement adjacent to our residence. The tree is 2 1/2 feet in diameter. It was a sapling when we moved to this property in 1955.
Over the past two to three years, the tree has not leafed out properly in the spring, and tended to drop its leaves early in the fall.
Indeed, it appears something is badly wrong. We would certainly like to save the tree by correcting its problems, if that is at all possible.
Accordingly, we would be very appreciative of any information you can provide. Would it be possible to have an inspection visit by a county farm adviser?
– Robert and Mearline Williams, Sacramento
A: During the drought years of 2008-10, native oak trees changed their growth patterns because of the lack of soil moisture, according to UC Master Gardener Bill Pierce. They had a continuous leaf drop that began in June and continued throughout the summer.
Perhaps that is all that ails your tree.
Decline may result from a succession of stressful conditions or events, such as: chronic or acute drought stress, drought exacerbated by heat, severe mineral deficiency, defoliation, root injuries, soil aeration deficits, pest infestation or disease.
When stress is prolonged or severe, secondary pests may accelerate the process, resulting in tree death. The aging process itself can cause or contribute to decline.
A good reference book is "Oaks in the Urban Landscape: Selection, Care and Preservation" by Laurence Costello, Bruce Hagen and Katherine Jones (University of California, $55, 265 pages). It is available for purchase at http:// anrcatalog.ucdavis.edu.
You may want to have an onsite inspection by a licensed certified arborist who specializes in oaks. For recommendations, contact the Sacramento County master gardeners at (916) 875-6913, 9 a.m. to noon or 1 to 4 p.m. weekdays.
GARDEN QUESTIONS?
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 h&g@sacbee.com. Please put "Garden Detective" in the subject field and include your postal address. To contact your UC Extension directly, call:
• Sacramento: (916) 875-6913; 9 a.m.-noon and 1-4 p.m. weekdays
• Amador: (209) 223-6838; 10 a.m.-noon Monday through Thursday; email ceamador.ucdavis.edu
• Butte: (530) 538-7201; 8 a.m.-noon and 1-5 p.m. weekdays
• El Dorado: (530) 621-5512; 9 a.m.-noon weekdays
• Placer: (530) 889-7388; 9 a.m.-noon on Tuesdays, Wednesday and Thursdays or leave a message and calls will be returned
• Nevada: (530) 273-0919; 9 a.m.-noon Tuesdays through Thursday or leave a message
• Shasta, Tehama, Trinity: (530) 225-4605
• Solano: (707) 784-1322; leave a message and calls will be returned
• Sutter, Yuba: (530) 822-7515; 9 a.m.-noon Mondays and Tuesdays and 1-4 p.m. Thursdays
• Yolo: (530) 666-8737; 9-11 a.m. Tuesdays and Fridays, or leave a message and calls will be returned
About Comments
Reader comments on Sacbee.com are the opinions of the writer, not The Sacramento Bee. If you see an objectionable comment, click the "Report Abuse" link below it. We will delete comments containing inappropriate links, obscenities, hate speech, and personal attacks. Flagrant or repeat violators will be banned. See more about comments here.