Here are a few things I have learned about rose hybridizing, many the hard way. I, when I first started breeding roses, found it very difficult to find any useful information on the how-to of breeding roses. I once read an article on how to sow rose seeds. The article said " just sow them in your garden in the fall and you will have rose seedlings in the spring". I took the advice and planted a year’s worth of work, several hundred seeds, in the garden. The following spring I had several million weeds and zero rose seedlings. Thanks to this uneducated advice I served the birds and mice a gourmet meal that winter. The person who wrote the article probably had the rose growing experience of adding water to a vase much less ever growing one from seed.
The first thing you must do is find out what roses are good seed parents and what roses are good pollen parents. I don't care what you are doing it will be a waste of time if the rose you are brushing pollen on will not set seeds. There are a few ways to do this, ask others that breed roses, read about the parentage of other roses, close observation and of course trial and error. You also need to know the Ploidy (I really don't think this is a word but I like it) number. If you are working with tetraploids make sure you have a male and female tetraploid. You can mix ploids (Again a gross misuse of the word) but you need to know what you will end up with for example, a tetraploid (4) and diploid (2) cross [the math is Female ploidy number + Male ploidy number =off spring ploidy number then divide by two (2). If the offspring number divided by two equals an uneven number the resulting offspring will be incapable (or nearly incapable) of dividing it's chromosomes in half to produce sex cells (pollen and seeds). Any uneven number will be either sterile or close to it. If you have to mix ploidy numbers remember you have a better chance of a conversion with pollen than with seed. Sometimes if you reverse the parents it can mean the difference between fertile and sterile offspring depending on what you are crossing. I have more information on this subject in the Hybrid Tea section. I also have a page on Rose Chromosome counts. I will start with emasculation (removing the pollen); I use tweezers and cuticle scissors. I have several small plastic containers with snap on lids, this is a must when carrying the containers around the yard full of pollen and you drop one. I start at either first light or late in the evening. I use blooms that are ready to open you will have to get know the bloom type to perfect your timing. As a general rule the more single the bloom is the quicker it will open. Weather will also be a factor; high humidity and/or cool weather will slow or even prevent some of the more double blooms from opening. You can use the ones that have just opened at first light if they haven't started to shed their pollen yet. I remove the petals and carefully remove the anthers with the tweezers letting them fall in the plastic container placed under the bud. I hold the container with my thumb and other three fingers except my forefinger and I position the bud over the opening with my forefinger. Be very careful not to damage the bud either by bending it to far or damaging it with the rim of the container. Remember you must remove all the anthers or you chance self-pollination. I snap the tops back on the containers as soon as I am done. I carry the containers in a plastic utility basket that hold about eight containers. I once dropped a container full of pollen trying to carry two uncovered containers into the house. When the pollen is collected I do one of three things, put the pollen in the refrigerator if I am going to wait awhile to use it. I put it in a cabinet to use the next day or so if the humidity is low. I place them in a small cooler with the top on. There is an inch or so silica gel covering the bottom (get the kitty litter kind it is cheaper) to dry out the pollen if humidity is high. Remove the lids when storing pollen except in the refrigerator, just set the lid on top of the container. I start pollinating the bloom the next day. With the lid on the container I shake the dry anthers to shed the pollen. I take my dry pollen and gently apply it with a soft, small, real hair paintbrush. You can tell when most roses are ready to receive pollen, The Pistil secretes a sticky substance that can be seen, as a general rule you remove the pollen one day and the bud is ready to receive pollen the next, but if in doubt dust it with pollen.
Every cross you do will not necessarily take, some roses will reject some pollen, so don't give up try different pollens that will get you in the direction you are aiming. I feel you should have a goal in mind and use roses that you feel will get you to that goal, not just any pollen on any flower, you can't tell if you are nearing your goal if you don't have one. You will have some surprises along the way even with a goal in mind but keep to your goal and if it is a good surprise keep it too but don't let it sidetrack you! You will know which crosses have taken, as the good ones will set hips, the ones that don't take will just wither and fall off.
Hip storage; In the fall before the first hard frost when the hips are ripe gather them separately and put them in zip-lock bags with the cross name written on the bag (it is customary to put the seed barer first such as "Peace" X "Rio Samba". If you tag the crosses as you make them keep the tags on the hip in the bag. Keep the hips in the refrigerator till you are ready to sow the seeds. Refrigeration has been proven to help in germination and health of the seedlings.
Germination; I start germinating in January or February up to as late as March as soon as the night temperature are above freezing. First I soak the seeds in enzyme as a chemical stratifier. Let me back up a little bit, the first thing I do is take the seeds out of the hip. I use a steak knife cut the hip in half or fourths and remove the seeds. I use the drain cleaner "Enforcer". I soak them for two days. Henry Kuska has a good article on this please read it. Just remember not to soak them over two days or the enzyme will kill the seeds. He says you can also use "Beano" I have never tried it. I have had good luck so far with the "Enforcer". I then place the seeds in seed starter trays, with out the dividers, keeping them separated by cross so you know what the seedling is when it sprouts. The trays (with top on) are covered with two layers of red plastic wrap (red light has also been proven to help germination). The trays have an inch of either white play sand or perlite just on the bottom. The seeds are planted in which ever medium you use. These trays are in the basement, which is not heated, under two shop lights per tray. When the seeds sprout I put the seedlings in their own seedling tray that have the peat dividers and are filled with seed starting mix. In the bottom I put a layer of vermiculite so if the roots grow through the bottom of the peat divider they are still in a moist environment. I keep a tray for each cross with the cross written on the lid with permanent marker, as seedling spouts it has a place ready to grow in.
If you have just a few crosses you can skip all the labeling but do all the other steps. When I first started rose breeding I had only three or four crosses so I just used one tray for all the same cross or seed parent. I just wrote the cross on the lid of the domed tray. I just bought some large and some small trays.
When the seedling out grows the starter trays I have peat moss pots to put them in, by this time they can be under the light with out the high humidity of the seed-starting tray domes. I use regular potting soil when moving them to the peat pots and the dividers are also peat so I just cut them apart and put the whole thing in the peat pot. I put the peat pots in a plastic tray, also with an inch or so of vermiculite for the same reason. At this time I start using fertilizer at about half strength. I use a spray of 1 part Hydrogen Peroxide to 9 parts water to keep my seedlings healthy. I have tried other methods but I have found nothing that works as well. I use this spray as a damping off preventative and it helps with blackspot and other rose diseases. It is cheap and safe. I learned of this from Mr. Kuska's Web Site, I have a link posted.
Hardening off; I try to get my seedling outside as soon as possible. When the seedlings have three or four sets of leaves or just seem strong enough to put outside. I put the seedling in the ground leaving a shallow depression with a bottomless milk jug over the seedling. The milk jug keeps the humidity higher till the seedling adjusts and the jugs can be removed in a week or two. Keep the seedling well watered during the transition. You may have to adjust this in your area depending on your growing season. I also use Gibberellic acid, which helps with early maturity.
Maturity; I water and fertilize my seedlings often to encourage their growth. I have read that fertilizing and watering make a rose "lazy" but I have found just the opposite result. The better health a rose has, the more foliage it produces. The more foliage a rose produces the equal amount of roots they produce to provide water and nutrients to the growth. A rose, like any plant, uses its roots not only for nutrient transportation but also as anchors so the bigger the plant grows the more anchorage it needs.
I never re-use potting soil or peat pots. The trays are re-used but I wash them with soap and water then bleach and let air dry before use. Using peat pots will save you time and in time will improve your soil.
The last and ongoing crucial part of rose breeding, and for me hardest, is deciding which seedling to keep and which ones to discard, I dispose of hundreds of rose plants yearly. The first or second bloom I discard based on symmetry, if rose lacks symmetry that will never improve so I cut my losses early. The following years I compost seedlings based on petal count, Bad color, Lack of vigor, and just plain lack of reason for being. You would be amazed how many roses start out full of vigor and decline with each year ending up puney and weak.
Spring 2003 this year I am trying a "Beano" soak for 48 hours followed by a "Gibberellic acid" soak for 24 hours then rinse. I will report the results.
Results: I found "Beano" worked as well as the "Enforcer". My results this spring (2003) were OK. I had fair results with everthing except my mosses with them I had better than average. This spring so far has been cool and long so that has also been a positive factor.
