Roses are still blooming in December

Frank Brines

Master Rosarian

Perhaps gardeners are among the first to experience the effects of climate change. Gardeners have increasingly been experiencing diseases and critters never before seen in the region. Many are results of the changing climate which brings new and unfamiliar environments from other regions.

One recent example of this, in my opinion, is the cancellation of the Palm Desert Rose Show Saturday, Nov. 12. Major rose exhibitors allegedly informed the show committee that their roses suffered severe damage from chilli thrips and the unusual high-temperature fall weather. In my nearly 40 years of growing roses in the Pacific Southwest District, it is the first show cancellation to my knowledge.

I mentioned last month that the Asian "chilli 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 western thrips with which gardeners are familiar. 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 blossom. Its damage resembles the effects of Roundup overspray or rose virus: severely stunted and very narrow leaves, stems and buds. Gardeners I've spoken with use several different products to gain some control, but a regular program is necessary with applications weekly at least.

All of this struggle should lessen those feelings of insecurity if your garden has not performed to your expectations this past season. I've heard many gardeners complain that pests and disease were out of control in August/September. Personally, my garden was untended for weeks in August and fell into that category as well, but that's on me.

If you're in this situation, the only practical road to control is to prune out the affected parts and consign them to the green waste bin. Then immediately apply a chemical insecticide spray and begin a spraying program as directions indicate or, every 7-10 days until control is reached, then at two weeks intervals.

Depending on which side of the valley you live, weather has been relatively good for our fall roses. Roses were still seen actively growing and blooming in many Temecula Valley gardens during the Thanksgiving holiday, as most areas still haven't had low temperatures anywhere near frost which, on average, occurs in mid-November. Normally, lower nighttime temperatures cool the soil and reset the roses' biological clock to slow down and go into a kind of dormancy. Roses need a four- to six-week dormant period during the winter months to allow them to undergo natural hormonal changes that prepare them for the next growing season, including forming buds at the base of the plant to produce new canes. At this point, aside from pruning away diseased branches as described above, I encourage you to not deadhead or prune until late January to early February.

Be sure to monitor your plants when daytime temperatures are warm: They still need to be kept hydrated. Also, do not fertilize until after the major pruning in January or February. I'll provide thorough information on all that early next year.

Speaking of fertilizer, the San Diego Rose Society is currently taking annual fertilizer orders for January delivery to have on hand when new spring growth is 2-3 inches long. Visit their website for more information at https://www.sandiegorosesociety.com/fertilizer-sale.

There is still time to order that new rose you have been dreaming about. Garden stores may still be adding to their list of orders or go to your favorite online nursery and make your order. There are many fine new roses out there. 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, go online.

Walter Andersen Nursery will soon have recently potted roses available. You can view the varieties that will be in stock by going to their website. I'm sure other nurseries will have similar information on their websites.

A few new varieties I find of interest are: At Last (floribunda, good apricot color, fragrance, disease-resistant); Bordeaux (floribunda/WineRed, 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 Redstriped gold, small clusters, mild fragrance, disease resistant, compact, hybridizers Christian Bedard & Tom Carruth); Gaye Hammond S (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 feet) growing habit, 60-65 petals, fragrant; it would be great for small spaces or en mass); Golden Iceberg (mild spicy fragrance).

For more ideas, visit TVRS' Rose Haven Heritage Garden at 30592 Jedediah Smith Road in Temecula, as well as http://TemeculaValleyRoseSociety.org/index.shtml. Enjoy the holidays of your choice as best you can – and spread the joy of roses.