As a Minnesota transplant I’ve become interested in breeding hardy shrubs, especially Rugosa hybrids. After four years I’m starting to see my first seedlings reach maturity–very rewarding.
I’m interested in how you experienced breeders working with Rugosas deal with the long lead time between germination and first bloom. About how many seedlings do you raise each year? Where do you put them? (Mine have taken over the entire vegetable garden so far.) How do you physically keep a tag or ID on the plants when they start to get bigger? When do you cull, and what do you look to eliminate first?
Thanks!
I usually cull for excessive early mildew and excessive thorniness in rugosas first. However, I live in zone 8b, so someone with a colder zone might cull differently. I find that they’re two common traits that make culling easy early on as to eliminate numbers for space to raise seedlings that show promise yet take at least 1 year to bloom.
Welcome to the wonderful world of Rugosa rose breeding! It is the ideal rose type to grow in northern (Zone 2 - 3) climates. Much more can be done to expand the colour range, develop new shrub and flower forms, increase floriferousness, etc.
I don’t have the luxury of lining out rose seedlings, so I cull them when they are very small growing in the container. It goes without saying, any seedlings having mildew are gone immediately. Foliage attractiveness is very important to me, so generally (crosses with some species or near species won’t produce seedlings of exceptional foliage quality) I only keep seedlings that are outstanding in this respect. This eliminates 95% of them.
As far as labeling the seedlings, there are many ways to do it. If you are lining the seedlings out, perhaps the best way is to put stakes into the ground with a label or writing on the stake indicating the cross of a particular batch of seedlings. Keep a record of them in a notebook in case something happens to your labeling.
Betsy,
The first time I raised some R.rugosa seedlings was about 4 years ago. They were very susceptible to powdery mildew and I culled about 90% of them because of that. A few bloomed in late summer that first year but most bloomed the next year. Because these were just some seeds that my mother-in-law collected for me and the plants are in the front landscaping I haven
Hi Betsy
I have a different vision of rugosa desease resistance and selection. My first breeding goal is desease resistance/tolerance.
Rugosa is a species with adaptations to wind swept areas, its resistances if conditions are bad fail: with poor air circulation mildew, BS and rust are often quite prominent. As seedlings with a confined environment a quasi certitude. That some earlier are more resistant is not linked with resistance when older. This is in a climate that at times induces every desease from repeated observations of entire progenies that were partly or totally heavily deseased when young and never more later.
I am renting a field and grow all seedlings without any early elimination for at least three years. Close to rugosa species seedlings are selected for good plant habit and nice flowers when outcrosses are mostly for different colors or nicer flowers as rugosa plant habit is lost usually.
I do map yearly seedling plantings and tag (durable yellow tags) the more interesting seedlings. Here french Riviera most seedlings bloom year two. Interspecific rugosa hybrids year three.
As for quantities: it is diversity dependent. With ample diversity you will never grow too large progenies. I grow many thousands yearly as with little ready made expectations I am exploring many complex combinations with many too little explored species.