Rose growing is a very difficult and labor intensive art form. I will try and help to clear up some ideas of propagation and disease control. There will also be some internet sites to help inform you of new cultivars and varieties of roses.

Plant propagation can be achieved by seed, stem cuttings, root cuttings and grafting.

Seed cuttings-

-Seed propagation is usually done with greenhouse roses and is only used for producing new cultivars. This is because the plants vary so much in genetic characteristics that you will never get a true-to-type plant from seed.

Stem cuttings-

-Stem cuttings are usually referred to as "own root" plants. Roses can be rooted from cuttings taken from flowering stems. Remember that younger wood roots faster and easier. Roses propagated by stem cuttings are seldom produced because they require considerable time and space to root. It is used though to overcome shortages of plants.

Root cuttings-

-Roses are seldom if ever propagated by root cuttings. You may get different colors of roses from root cuttings than what you have on the stem. This is most likely do to a periclinal chimera. This is where the bud tissues are different genetically from those of the roots. Therefore giving you a different flower color.

Grafting-

-Grafting is used not only to give you hardy rootstocks but also to increase a population that is in shortage during the winter months. Another type of grafting used is bud grafting. Here you are just taking the bud of a plant that you want and grafting it in place of a bud on the original plant.

For more information on propagation I invite you to look at the following web sites.

http://www.rooting-hormones.com/rose.htm

http://www.cals.cornell.edu/dept/flori/hort400/rose/rosetbl.html
 

Diseases are a common problem among all plants. There is always an organism out there that will feast on it. I will talk about the most important and detrimental disease, Black Spot. You may also here it called leaf blotch, leafspot, black blotch, stary sooty mold, rose Actinonema and rose leaf Asteroma.

Black blotch induces leaf defoliation and may greatly weaken the plants. They are unsightly due to the yellowing of the leaves and leaf drop. It also cause a reduction in the length and strength of stems as well as the quality of flowers. This pathogen is restricted to only the Rosa spp.

Symptoms of black spot occur on the leaves, canes, petals, petioles among other parts of the plant. Below is some helpful information on diagnosing the problem.

--Leaves

-characteristic black and brown spots on upper surface. They contain feather mycelial strands. White chlorosis extends throughout the leaves and the leaf eventually turns yellow. The premature yellowing and abscission of leaflets is associated with ethylene. Green leaves with blackspot produce large amounts of ethylene and decreases as they become yellow. For those who don’t know. Ethylene is a gas that hastens maturity.

--First year canes

-develop a purplish-red, raised, irregular blotches on immature wood of highly susceptible varieties. Spots later become blackened, blistered, and dotted with black fruiting bodies. Lesions are tiny and rarely kill branches. But these lesions will aid in overwintering survival of the pathogen.

--Petioles and stipules

-have inconspicuous black spots similar to those that you find on the leaves. Girdling may also occur without leaf abscission.

--Petals

-red dots and distortion of the flower occurs. Small black pustules (acervuli) are found in the lesions.

Below are some web sites that can help in trying to prevent and fight off blackspot as well as other common diseases among roses.

http://metrokc.gov/hazwaste/house/garden/controlrose.html

http://randomaccesssolutions.com/Diagnosis/Witches%20broom.htm

http://media-net.net/clients/plantdr/flowers/fall_rose_care.htm
 

There are areas of roses that can be improved. The problem is just finding how to improve it. Disease resistance varieties include only R. cinnamomea and r. pendulina. If there is any hope to overcome these detrimental diseases we need to find out what makes these varieties, among a few others, resistant to blackspot. Most are native to Europe and Asia. Maybe the answer lies there but until further work is done, there will always be those few things that keep the rose from being perfect. They may contain the environmental factors, or it may be the age of the leaves on the plant. There are many possibilities to look at.