Propagating Roses
How To Grow Roses From Seed
By C. H. Lewis, Salem, VA
The following was published in the October, 1958 issue of The American Rose, pages 16, 17, and 29.
THE beauties of the child are most evident to the parent. So with the rose. Though its charms are sweet to all, they are sweeter to him whose fostering hand raised it from seed. Thus, on several occasions over a period of years, I have harvested, planted, and watered the seeds of many roses, and anxiously awaited the germination and development of each tiny seedling.
Depending on your wish and purpose, experiments with rose seedlings may be conducted with seeds from either planned (cross-pollinated) or natural (open-pollinated) crosses.
Protect Parents
If you want to make your own crosses, you must start preparations during the flowering season by protecting selected blossoms of both parents from natural methods of fertilization, then make manual crosses with varieties of your choice and finally let the hips containing the seeds mature naturally on the plant before harvesting them in the Fall after the second heavy frost.
The most important part of any experiment is maintaining detailed, up-to-date records. Should you make planned crosses, your first notes will record each cross as to parentage, date, etc. Your records are not complete unless you make a diagram or plot plan of the exact location of each variety as it is transplanted to open ground. Also, be sure to record the bloom; its color, whether it is single or double and any unusual characteristic you may detect. Note if the plant repeats. Preserve and maintain these records during future bloom periods or seasons.
Have a seed flat ready to use as soon as you harvest the seeds. It is preferable to make it with untreated cypress boards, which will last for years without the use of any preservative. Cedar wood is rated next to cypress for this purpose. Any size flat may be used, governed by the space you have available and the number of seeds you wish to plant. The flat should be approximately 4" deep so that it will hold at least 2" of soil plus a 1" top layer of vermiculite (expanded mica used as a rooting medium to minimize disease, especially the deadly seedling damping-off fungus). The soil under it supports and sustains growth of the seedlings with minimum attention. Soil sterilized with live steam is preferred to chemically-treated soil. Almost any commercial greenhouse will give you enough sterile soil to fill your seed flat.
Moisten the soil and vermiculite in the flat well with pure rain water, rather than the chlorinated or chemically-treated water found in most cities, mine included. Then place the seed flat in a window having a northerly exposure. The temperature may range from 40 to 70°F.
Prepare Flats
Now you're ready to mark off the seed flat into areas, divisions or rows according to your needs. I use rows 2" apart, with each row separated by small-gauge, flexible copper wire stretched across the top of the flat and securely fastened at each end of it.
Next make a protective covering for the flat with 1/4"-mesh wire on a light-weight frame.
Collect the seed pods of your planned crosses first. Then gather the most colorful seed pods from other varieties and also from the ground, if you are positive of their identity. As a general rule, the most colorful pods are more mature and will germinate in less time. Collect one variety at a time, and be sure to properly identify and record each one.
A rubber mallet is useful for opening the seed pods. You can plant the seed immediately without any cleaning, testing, drying, refrigeration or treatment of any kind. In earlier experiments, I disinfected some seed with a 10% formaldehyde solution, but after several experiments, I discontinued this practice since there was no appreciable difference to warrant it.
Plant the rose seeds 1/2-3/4" deep in the vermiculite. Plant all the seeds from each variety together in the same row. Separate the different varieties with well-marked aluminum strips or tabs placed in the growing medium. You don't need to sow each seed individually. This is too time-consuming. Just pour the seeds from the envelope that you stored them in directly into the row. Even though they may be sowed as thick as mustard, tests have proven that they will still germinate without any ill effects.
Keep Seeds Moist
Keep the seeds moist at all times. Generally, you only need to water two or three times each week with a sprinkling can. Again use pure water, if possible.
Now comes the hard part - the waiting period. Don't be impatient. Some seeds take years to germinate. For instance, none of the 'Rose damascena' seeds that I planted on October 24, 1956, germinated by January 19, 1958. 'Harrison's Yellow' and 'Gloire de Dijon' seeds planted the same day began to germinate on November 11, 1957 and December 3, 1957, respectively. Others don't take as long. Seeds from an unnamed once-blooming seedling resulting from a cross of 'Black Prince' x 'Grande Duchesse Charlotte' planted on the same day began to germinate on December 26. 'Countess of Stradbroke' planted on October 24 germinated on January 13. Climbing 'Mrs. P. S. DuPont' planted on October 24 germinated on November 28. Seed from an unnamed shrub seedling of 'Mme. Lombard' planted November 1 germinated on December 5. 'Spanish Beauty' planted on November 16 germinated on January 18. 'Sunday Best' planted on November 16 germinated on February 1. 'Reveil Dijonnais' planted on December 5 germinated on April 7. 'Mermaid' planted on December 5 had not germinated by October 11. 'Billy Boiler' planted on December 21 germinated on May 15.
I purposely left several varieties of seed pods on the plants until late Winter to expose them to our lowest temperatures (as low as 8°F) before collecting and planting them. Among these were 'Queen Elizabeth' (planted February 6, germinated April 11) and 'Rosa setigera' (planted February 18, not germinated by October 11).
When To Transplant
The seed flat, of course, will not accommodate the growing seedlings indefinitely. It all depends on the conditions of weather, space, time available, etc., as to whether to transplant the seedlings to individual pots or to open ground. In either case, they require more attention than while in the seed flat. Potted seedlings require regular and frequent watering. Also, it is not always easy to find a suitable location with proper temperature, humidity, light and air circulation for potted plants if you do not have a greenhouse. For instance, in March 1957 some of the seedlings in my flat were being damaged by growing through the wire frame covering them. I thought that it would be quicker to pot about two dozen of the tallest seedlings than to make a higher frame cover. I did so, then placed these potted seedlings on shelves in a work shop window. The outside temperature was unusually high during the latter part of March, and very few potted seedlings survived. As the weather continued unduly hot, I had to do something else or take a chance of also cooking the seedlings remaining in the flat. So, I moved the flat outdoors under the shade of a tree, and began to transplant the seedlings to the open ground. Some of the plants already had buds on them. A 'Climbing Mrs. P. S. DuPont' seedling began to bloom on May 2, 'Spanish Beauty' on May 15 and 'Sunday Best' shortly thereafter.
Since all of the seeds had not germinated, I left the seed flat outdoors under the shade of the tree during the Summer. The seeds lay inactive during the hot weather. But, as soon as our Fall rains and cool nights arrived, I moved the flat to its former location inside for further germination. During the past Winter and Spring as many seeds germinated as during the first year after planting.
You can't imagine how much joy this one small box creates over a period of many years. Why don't you try it yourself this Fall?
Depending on your wish and purpose, experiments with rose seedlings may be conducted with seeds from either planned (cross-pollinated) or natural (open-pollinated) crosses.
Protect Parents
If you want to make your own crosses, you must start preparations during the flowering season by protecting selected blossoms of both parents from natural methods of fertilization, then make manual crosses with varieties of your choice and finally let the hips containing the seeds mature naturally on the plant before harvesting them in the Fall after the second heavy frost.
The most important part of any experiment is maintaining detailed, up-to-date records. Should you make planned crosses, your first notes will record each cross as to parentage, date, etc. Your records are not complete unless you make a diagram or plot plan of the exact location of each variety as it is transplanted to open ground. Also, be sure to record the bloom; its color, whether it is single or double and any unusual characteristic you may detect. Note if the plant repeats. Preserve and maintain these records during future bloom periods or seasons.
Have a seed flat ready to use as soon as you harvest the seeds. It is preferable to make it with untreated cypress boards, which will last for years without the use of any preservative. Cedar wood is rated next to cypress for this purpose. Any size flat may be used, governed by the space you have available and the number of seeds you wish to plant. The flat should be approximately 4" deep so that it will hold at least 2" of soil plus a 1" top layer of vermiculite (expanded mica used as a rooting medium to minimize disease, especially the deadly seedling damping-off fungus). The soil under it supports and sustains growth of the seedlings with minimum attention. Soil sterilized with live steam is preferred to chemically-treated soil. Almost any commercial greenhouse will give you enough sterile soil to fill your seed flat.
Moisten the soil and vermiculite in the flat well with pure rain water, rather than the chlorinated or chemically-treated water found in most cities, mine included. Then place the seed flat in a window having a northerly exposure. The temperature may range from 40 to 70°F.
Prepare Flats
Now you're ready to mark off the seed flat into areas, divisions or rows according to your needs. I use rows 2" apart, with each row separated by small-gauge, flexible copper wire stretched across the top of the flat and securely fastened at each end of it.
Next make a protective covering for the flat with 1/4"-mesh wire on a light-weight frame.
Collect the seed pods of your planned crosses first. Then gather the most colorful seed pods from other varieties and also from the ground, if you are positive of their identity. As a general rule, the most colorful pods are more mature and will germinate in less time. Collect one variety at a time, and be sure to properly identify and record each one.
A rubber mallet is useful for opening the seed pods. You can plant the seed immediately without any cleaning, testing, drying, refrigeration or treatment of any kind. In earlier experiments, I disinfected some seed with a 10% formaldehyde solution, but after several experiments, I discontinued this practice since there was no appreciable difference to warrant it.
Plant the rose seeds 1/2-3/4" deep in the vermiculite. Plant all the seeds from each variety together in the same row. Separate the different varieties with well-marked aluminum strips or tabs placed in the growing medium. You don't need to sow each seed individually. This is too time-consuming. Just pour the seeds from the envelope that you stored them in directly into the row. Even though they may be sowed as thick as mustard, tests have proven that they will still germinate without any ill effects.
Keep Seeds Moist
Keep the seeds moist at all times. Generally, you only need to water two or three times each week with a sprinkling can. Again use pure water, if possible.
Now comes the hard part - the waiting period. Don't be impatient. Some seeds take years to germinate. For instance, none of the 'Rose damascena' seeds that I planted on October 24, 1956, germinated by January 19, 1958. 'Harrison's Yellow' and 'Gloire de Dijon' seeds planted the same day began to germinate on November 11, 1957 and December 3, 1957, respectively. Others don't take as long. Seeds from an unnamed once-blooming seedling resulting from a cross of 'Black Prince' x 'Grande Duchesse Charlotte' planted on the same day began to germinate on December 26. 'Countess of Stradbroke' planted on October 24 germinated on January 13. Climbing 'Mrs. P. S. DuPont' planted on October 24 germinated on November 28. Seed from an unnamed shrub seedling of 'Mme. Lombard' planted November 1 germinated on December 5. 'Spanish Beauty' planted on November 16 germinated on January 18. 'Sunday Best' planted on November 16 germinated on February 1. 'Reveil Dijonnais' planted on December 5 germinated on April 7. 'Mermaid' planted on December 5 had not germinated by October 11. 'Billy Boiler' planted on December 21 germinated on May 15.
I purposely left several varieties of seed pods on the plants until late Winter to expose them to our lowest temperatures (as low as 8°F) before collecting and planting them. Among these were 'Queen Elizabeth' (planted February 6, germinated April 11) and 'Rosa setigera' (planted February 18, not germinated by October 11).
When To Transplant
The seed flat, of course, will not accommodate the growing seedlings indefinitely. It all depends on the conditions of weather, space, time available, etc., as to whether to transplant the seedlings to individual pots or to open ground. In either case, they require more attention than while in the seed flat. Potted seedlings require regular and frequent watering. Also, it is not always easy to find a suitable location with proper temperature, humidity, light and air circulation for potted plants if you do not have a greenhouse. For instance, in March 1957 some of the seedlings in my flat were being damaged by growing through the wire frame covering them. I thought that it would be quicker to pot about two dozen of the tallest seedlings than to make a higher frame cover. I did so, then placed these potted seedlings on shelves in a work shop window. The outside temperature was unusually high during the latter part of March, and very few potted seedlings survived. As the weather continued unduly hot, I had to do something else or take a chance of also cooking the seedlings remaining in the flat. So, I moved the flat outdoors under the shade of a tree, and began to transplant the seedlings to the open ground. Some of the plants already had buds on them. A 'Climbing Mrs. P. S. DuPont' seedling began to bloom on May 2, 'Spanish Beauty' on May 15 and 'Sunday Best' shortly thereafter.
Since all of the seeds had not germinated, I left the seed flat outdoors under the shade of the tree during the Summer. The seeds lay inactive during the hot weather. But, as soon as our Fall rains and cool nights arrived, I moved the flat to its former location inside for further germination. During the past Winter and Spring as many seeds germinated as during the first year after planting.
You can't imagine how much joy this one small box creates over a period of many years. Why don't you try it yourself this Fall?
