Time to let rose bushes rest
Last updated 12/12/2019 at 8:36pm
Depending on which side of the canyon gardeners live, the past few weeks have produced much needed rain and, for some folks, too much of a good thing. In any case, the roses are appreciating the break.
After being buffeted around, shoved from hither to yon and finally getting a great shower removing the dusty layer from more recent Santa Ana winds and rehydrated soil, a resting period will be a welcome state.
Most areas still haven't had temperatures anywhere near frost. Roses could still be seen actively growing and blooming in many gardens during the Thanksgiving holiday. This cold rain and temperatures will cool the soil and reset the roses' biological clock to slow down and go into some kind of dormancy.
Roses need a four- to six-week rest or "dormancy" period during the winter months. During dormancy, the plants go through natural hormonal changes that prepare them for the next growing season. Dormancy is triggered by a variety of factors. Cold temperatures, including frost, slow the plant's metabolism while cold rains chill the soil further slowing growth rate.
Gardeners can help promote dormancy by not deadheading or pruning this month. Allow the rose "hips" to set and mature so they can send hormonal signals to the plant that it's time to rest and marshal its energy for a vigorous growth spurt in the spring.
Just the same, be sure to monitor the plants when daytime temperatures are warm as they still need to be kept hydrated. Also, do not fertilize until after the major pruning in January or February and only after a couple inches of new growth.
On the topic of pruning, some gardeners are anxious to prune their roses in December. That's understandable because the area hasn't had a hard frost yet even though the average date for first frost in the area is Nov. 17.
Pruning now not only prevents dormancy, but also produces tender new shoots that will most likely be killed by the next hard frost. So, the bottom line is please wait four to six weeks after the first frost to do a major "spring" pruning.
In the event that there is no frost or freeze it is typical to prune by mid-February. Watch the Temecula Valley Rose Society website or local newspapers for the dates for free spring pruning workshops. I will be presenting a one-day, one-time pruning demonstration Jan. 26, at 10 a.m., at Rose Haven Heritage Garden, 30592 Jedediah Smith Road, in Temecula. Come prepared to learn and to participate in this hands-on workshop.
I mentioned in November that the Asian "chili thrip" is spreading rapidly in the Southwest and is becoming a global threat. This pest is extremely successful and particularly resistant to conventional control methods.
The chili thrip is even smaller than the thrips gardeners are familiar with. It works in similar ways, only more devastating and more difficult to control. It doesn't seem to have any preferences except new growth of almost any plant and blossoms.
Gardeners with whom I've spoken use several different products to gain some control, but a regular program is necessary with applications weekly at least. Its damage resembles the effects of Roundup over spray or rose virus: severely stunted and very narrow leaves, stems and buds.
Cool, moist air promotes mildew and rust, so be watchful for these fungi. Be prepared also for spraying with a dormant spray immediately after the spring pruning. Read the label and be sure to buy enough to thoroughly cover plant and garden bed. I find that a 2-gallon pump sprayer with 2 gallons of mix will cover about 15 rose plants after pruning.
There is still time to order that new rose gardeners have been dreaming about. Garden stores may still be adding to their list of orders, or visit a favorite online nursery and make an order. There are many fine new roses that gardeners simply must have in their collection. Many are more disease resistant than in the past. Most nurseries or wholesalers no longer print catalogs, so for a list of current roses available from each gardeners will have to go online.
A few new varieties I find of interest are: At Last (floribunda, good apricot color, fragrance, disease-resistant); Bordeaux (floribunda/wine red, large blooms, heat tolerant, disease resistant); Easy Spirit (floribunda/white, hybrid T form, fragrance, hybridizer Tom Carruth, disease resistant, lasting form); Frida Kahlo (floribunda/scarlet red-striped gold, small clusters, mild fragrance, disease resistant, compact, hybridizers Christian Bedard and Tom Carruth); Gaye Hammond (bright yellow with touches of orange, slight fragrance, disease resistant, bloom making machine); Parade Day (grandiflora/fuchsia pink striped white, strong fragrance, hybridizer Christian Bedard, holds color); Flowerland (shrubby, pink, low (1.5-foot) growing habit, 60-65 petals, fragrant; it would be great for small spaces or enmass); Golden Iceberg (mild spicy fragrance).
For more information, visit http://www.TemeculaValleyRoseSociety.org/index.shtml.