by Donald W. Trotter Ph.D.
No pruning is necessary other than removal of dead canes and tips.
Hard pruning is recommended for newly planted bush roses of the hybrid tea, grandiflora and floribunda tribes. Hard pruning is often used by growers to produce show blooms for exhibition.
This method is not good for established garden roses and should not be practiced. It can still be used to rejuvenated sickly plants and neglected ones, but hard pruning is no longer accepted as correct pruning.
Moderate pruning is the accepted method for treatment of established garden roses. Floribundas, hybrid teas, grandifloras, and tree roses all respond best to this pruning practice. If the roses are fed well, you can expect show quality roses on beautifully shaped bushes.
Light pruning is not generally recommended as it will produce spindly bushes and if practiced year after year will result in an early blooming bush with poor quality flowers.
In special cases such as very vigorous hybrid teas, climbers and shrub roses, light pruning is the only recommended way to cut these plants.
Chemical insecticides are only effective until the target pest develops a resistance to that chemical. Then it becomes necessary to alternate harmful substances to control an insect population that continually gets worse because of lack of competition and natural predators due to high concentrations of chemicals. The major rose pests that we encounter here in Southern California can be controller by establishing populations of two beneficial insects and periodic treatments with a bacterial and a seed extract. The two beneficial insects are the Green Lacewing and Trichogramma Wasps. These two insects will guard your roses against everything from Aphids to some Scales and Spider Mites. Lacewings are very active and voracious feeders who's host or target prey are aphids, mealybugs, whiteflies of some species, juvenile scale insects, and some spider mites. The tiny Trichogramma wasp is a parasite of caterpillars some species of bud worm and will antagonize a number of other butterfly and moth species. These parasites do not have a stinger (no need to fear them), they have an ovipositor that lays her eggs inside the host. As the wasp larvae develop they use the host as a food supply.
The bacteria that I spoke of is Bacillus thuringiensis Kurstaki or Berliner. This product is often referred to as BT and is a paralyzing bacteria that affects many species of worm and caterpillar including the leaf skeletonizer worm. By paralyzing the stomach of its host this bacteria is very useful against its target pests.
The seed oil that I was referring to is Oil of the Neem Tree of India. The active substance in this sap has been named Azidirachtin after the botanical name of the tree. The extracted oils from the tissue of the seed of this tree are very effective at repelling and keeping your rose bushes free of any sign of insects. Although it smells like hazelnut to us it has the most repellent affect on pest insects. Neem oil is sold under the name Bio-Neem under the Safer label and Rose Defense under the Green Light label. These two products can be found at any garden supply store.
Controlling diseases in your rose garden is really not very difficult at all. There is no need for harmful fungicides that can cause severe physical problems or have a negative affect on outdoor pets and bees as well as wipe out entire earthworm populations from a single spraying. Balanced nutrition and a couple of minerals can keep your garden disease free without weekly exposure to chemicals.
Most diseases of plants will leave a healthy plant alone. It is the same with us, if we're healthy we don't get sick. Plants also have immune systems. This is where a balanced diet that contains the proper amount of copper, sulfur, potassium, magnesium and calcium will ensure that certain very commonplace and damaging fungi don't get a foothold in your garden.
Potassium is very important for resistance against powdery mildew and rust on roses. Not in some crazy amount that is available to the plant in five seconds after application but instead long lasting natural sources from mineral deposits or from other natural source. When potassium is broken down in the soil by a healthy soil it will actually help to prevent the onset and spreading of powdery mildew and rust, which are tough problems for most chemical gardeners to control. High calcium levels along with an abundance of naturally available magnesium will cause your roses to produce thick healthy canes without problems with of slow root development in our heavy soils. Copper and sulfur are the two elements which I use as a spray fungicide if absolutely necessary. Other than dormant spraying minimal spraying should be necessary to prevent fungus and disease if the roses are fed naturally.
Natural fertilizers are released after the natural biodegradation process occurs in the soil thus enriching the soil as the rose plant is fed with a balanced supplement. Natural fertilizers are also often very long lasting thus minimizing the release of carbon dioxide form the soil. The use of chemical fertilizers in residential as well as agricultural and industrial applications is responsible for a great deal of greenhouse gas escaping from our soils. When natural fertilizers are used a process known as carbon sequestration occurs. Carbon is the universal filter, sponge and storage facility for toxins and assists in the creation of environments where organisms can survive with a greater degree of health. Remember that most filters that remove impurities form water are different grades of carbon. When soils digest natural fertilizers they do so with bacteria and a number of micro organisms. Organic matter is turned to food and plants can achieve a greater level of health in these conditions. No speed is lost, nor are roses any smaller or fewer in number when fed naturally. They are just healthier, thus more trouble free.
Natural rose foods are used less often due to their slow rate of release into the soil. This means, of course, fewer trips into the garden to feed=less work=smaller cash expenditures on fertilizers. This equation certainly seems logical.
Several good organic rose foods are produced on the open market. Whitney Farms produces the most recognized natural rose food, and it is very good. The Grow More Company also produces a superior rose food that can be purchased at Grangetto's along with the Whitney Farms rose food. Over the years I have developed a rose fertilizer that works very well and is used less often than all of the commercial brands. It has been broadcast on the television, and radio , and it appears regularly in a score of local newspapers and magazines. The recipe is as follows:
Not only will this rose food do its job, but it will improve your garden soil while it works to feed your rose bushes. All of the components in this recipe are available at Grangetto's Farm and Garden Supply in Encinitas.
I suggest the use of Sulfate of Potash Magnesia instead of Epsom Salt as a magnesium source. Sul-Po-Mag is very inexpensive and goes a long way. you are also applying more that just magnesium. This mined mineral compound is rich in potassium, which we know as the third number in commercial fertilizers and its disease fungus fighting capabilities. The small amount of sulfur in this product is very useful for reasons previously discussed. One cup per rose during the dormant period will do all of the things that Epsom Salt does without the salinity and the problems associated with salinity. Sul-Po-Mag breaks down more slowly so the plant gets a regular supply of these nutrients. Epsom Salts are 100% water soluble and what isn't immediately used by the plant is either washed form the surface of the soil during rain or is leached away by rain or irrigation. Sul-Po-Mag can be purchased at many garden centers and Grangetto's. This product is only applied once a year.
In closing, I would like to stress the importance of a good layer of organic compost or mulch in the rose garden. This is fuel for the many organisms that make soil rich and healthy. Any commercial compost can be used or homemade is the best. Remember that organic matter is the food of earthworms. More compost=more earthworms=more porous soil that accepts water better and doesn't dry out nearly as fast=savings on the monthly water bill.
This seminar and the accompanying literature are copyrighted and are the property of The Organic Gardener's Resource Centre, reproduction of this material without permission is okay by me!
You can find more of Donald Trotter's articles at his site for Growing Roses Organically. For more information, please contact:
Donald W. Trotter Ph.D.
The Organic Gardener's Resource Centre
295 Neptune Avenue
Encinitas, CA. 92024
is copyrighted. No reprints without permission