Rose Care FUNdamentals for March 2019
Last updated 3/11/2019 at 7:43pm
Location, Location, Location. Depending on location – or more specifically, that of the garden – gardeners may have experienced frost damage to their roses and tender young plants recently. The past week and the forecast for the first weekend of March is for cool to cold temperatures around Riverside County. All areas of Southern California have had above average rainfall. Some may even see a little more snow. Even gardens in the same general vicinity may have different effects due to their prevailing micro-climates. These wintry temperatures could delay growth of vegetation and bloom time due to the cooling of the ground as well as the air. It is comforting that all of this rain will flush excess salts that may have built up from irrigating and fertilizing.
If the roses experienced fungal diseases last year, gardeners might think of applying a lime sulfur dormant spray soon. First, make sure the garden is free of left-over debris and to dispose it in the green garden waste bin – do not compost rose debris in the yard. Also, remove all old leaves that may be left on the bush. This cleanliness will help keep down disease. Read the dormant spray label completely to ensure the proper strength of the mixture for “growing season instructions.” Be sure to saturate all canes and the soil surface of the entire bed. Maintain a minimum of 2-4-inches of organic composted mulch over the entire garden surface to insulate the upper 8-12-inches where most rose roots feed and to reduce evaporation and conserve water, while still providing sufficient moisture. It will also supply nutrients to build the soil for the roses over the season.
If there is space available and a gardener hasn’t yet purchased new roses, they can still do so and they might find some great offers. Over the past several years, there has been a drop in the number of new varieties introduced into the market and commercial rose production has dropped, so there is less of a selection at fewer outlets. Some nurseries are still shipping to this area. Plants already in pots are the best to buy as they will be far easier to transplant and will establish themselves quicker. Look for those with 3-5 major canes.
Take time now to inspect and make any necessary repairs to the irrigation system. Drip systems are the most efficient, and they avoid problems created by above-ground sprayers and sprinklers, which waste water and can foster molds like mildew and rust. If possible, avoid any overspray or misting of water being applied elsewhere in the garden that may hit the roses, but if a garden does use overhead watering systems, avoid doing so when there is any wind to avoid moisture evaporating or collecting on leaves which could result is sunburn or add to conditions favorable for fungal diseases. For best results and efficiency, be sure to time the irrigation so it is complete before the day gets hot, preferably by midmorning, that is, 8-9 a.m. Avoiding daytime watering prevents excess ground moisture into nighttime. Too wet soil can lead to unhappy roots and fungal diseases.
Now would be the time to sprinkle 1/2 cup to 1 cup of Epsom salts widely around each rose bush; use half as much for minis and mini-floras. There is some indication that this treatment helps stimulate new cane growths known as “basal breaks” at the “bud union,” which is the big part next to the ground where grafting was done.
When new growth is 2-3-inches long, begin fertilizing. I suggest an initial feeding each year be higher in nitrogen (N) to encourage new stem and leaf growth. In about two weeks, apply fertilizer that is higher in phosphate (P) and potassium (K) to give roots a boost at start of season. New information suggests that continued use of fertilizer higher in P and K will foster greater root development and lead to better growth, resistance and healthier plants. Look for fertilizers rated as 8-10-8 that include micro elements for greater results.
I highly recommend organic type fertilizers versus inorganic or “chemical” ones. Organics foster better soil development, a richer, livelier, more viable community of soil organisms that break the elements into easily absorbed form and release them slowly. They will “build” soil structure into a healthy component, and when used regularly will develop a soil rich in reserve energy, allowing gardeners to use less product with the same results.
There are rose events coming up which may be of interest. The Pacific Southwest District Rose Show and Convention, April 26-28, is at L.A. Arboretum, 700 West Huntington Drive, in Monrovia.
The San Diego Rose Society rose show May 4, is at the El Cajon Community Center. Plan to attend and experience seeing the blooms of many favorite roses or to research possible new additions to the garden. Entry applications for garden show at the San Diego Fair are now being accepted. Inquire http://www.sdfair.com.
Be sure to visit the Rose Haven Heritage Garden is located at 30500 Jedediah Smith Road at the cross street of Cabrillo Avenue in Temecula. The 3.4-acre rose garden is owned and maintained by the Temecula Valley Rose Society, a nonprofit organization supported with donations. Look for the donation box when visiting. Also, visit the website at http://www.TemeculaValleyRoseSociety.org regularly for great information and schedule of events. Spread the joy of roses.