Questions from the Help Desk

Feb 11, 2014

UC Master Gardeners of Napa County answer garden questions at our Help Desk on Mondays, Wednesdays, and Fridays from 9:00 a.m. - 12 noon. Free advice is given for growing conditions in Napa County.

Drop-in: UC Master Gardeners of Napa County, 1710 Soscol Avenue, Ste 4

By phone:
877-279-3065 (toll free for American Canyon/Up valley residents)

Complete the 
diagnosis form or e-mail 

Following are some examples of recent questions asked of our Help Desk volunteers. Thanks to Monica Finigan for summarizing them. Read further information on these subjects at

Pruning Oleander: 

Client called to ask if it was OK to prune an oleander in December. Client was advised that oleanders should be pruned in the period of late summer to autumn. Source: American Horticultural Society Pruning and Training, by Christopher Brickell and David Joyce. Please note: this book is an excellent resource for questions on pruning and training specific plants.








Frost Damage in Citrus:

Several clients called about frost damage to citrus. They were advised to remove any frost-damaged fruit now but to wait several months before making an assessment of the extent of the damage to the trees. When warmer weather occurs in the spring, the frost-killed twigs and branches will become apparent and can be pruned out without removing healthy portions of the tree. Heavy pruning should be postponed until the following year, so that the plants can regain their full canopy. In the meantime, the clients were urged to follow the frost protection measures described in ANR publication 8100.



Pruning Hydrangea:

Client asked whether frost-damaged hydrangea should be pruned now. Client was advised to wait until spring toassess the damage. Prune the previous year's flowered branches by up to 12 inches, cutting to fat buds. Badly cold-damaged plants may be cut to the base in the spring, but there will be no flowers the following summer if the hydrangea is the type that blooms on old wood. Newer varieties, such as the Endless Summer series, will bloom on new wood.


Pollinating Kiwis:

Client called to ask if her Vincent male kiwi would be able to pollinate her Hayward female plant. She was advised that for pollination to occur, the male cultivar needs to have pollen when the female cultivar is receptive. For this reason, the Vincent cultivar cannot be used to pollinate the Hayward. The ‘Chico, Matua or Tamori male vines can be used to pollinate the Hayward on a 8:1 female-male ratio.