COLLECTING, STORING, AND UTILIZING POLLEN
Pollen can be collected from cut blooms or from blooms that are left on the plant to be pollinated later with pollen from another variety. Both methods are effective and are described below. In general, select a bloom that is partially open, in a loose bud stage. The "ideal" stage for a variety depends on the number of petals in the bloom. For single blooms (having 5-12 petals), pick buds in a "soft bud" stage, when color is just beginning to show. For a double bloom with few petals (25-35), the flower should be no more than one quarter open. Very double flowers should be nearer the one-third to one-half open stage to permit the anthers and their pollen to mature. The intent is to select blooms with anthers that are fresh, yet mature enough to yield pollen when dry. A common test as to whether a bloom is far enough along to use is to lightly squeeze the bloom with your fingers. If the bloom does not have any "give", it is too early. The anthers should be plump and light in color, normally yellow but sometimes white, greenish white, or red. If one is not interested in using the plant (as a mother) from which the pollen is being provided, one can use the "cut bloom" method.
CUT BLOOM METHOD: There are 2 variations to this method.
1) Cut the bloom from the plant, leaving a half inch or so of the stem as a handle. Carefully pull off the petals. Place the flower with the stamens downward in a 2 by 2 inch zip lock plastic bag. Put the plastic bag over the flower that you desire to pollinate (and have already removed the petals and stamens) with the stamens touching the stigma. I use this method with plants such as John Davis which are almost always in flower and are not good mothers but do have good pollen.
2) Cut the bloom from the plant, leaving a half inch or so of the stem as a handle. Carefully pull off the petals. Lay the stems of one variety on a sheet of waxed paper. Mark each sheet as to variety. Place each sheet, uncovered, in a dry, warm (at least 68 degrees-F) area away from direct sun and wind or drafts. An example system would be to use a picnic cooler which contains a cotton bag of calcium chloride (commonly available from hardware stores). The calcium chloride will removed any excess moisture from the picnic cooler. Most pollen will be mature in 24 to 48 hours. The pollen color may be white, yellow, orange, or red. The powder-like grains of pollen will be visible on the paper when the stem is shaken. Grasping the stem, shake the pollen onto the waxed paper and then put the collected pollen into a clean wide mouth container which is air tight, such as a plastic perscription pill container. Plastic containers have an advantage over glass. If one plans on refrigerating the pollen, a glass container takes longer to warm up after being removed from the refrigerator. If the container is opened before reaching room temperature, moisture can condense on the inside and ruin the pollen. Do not use any container that has a rubbery seal or any glue-like or oily residue in the cover. Write the variety name and the date collected on the cover. I use this method with plants that have a very large main flush (like William Baffin) to collect a very large amount of pollen for refrigeration so that it can be used later.
CUT ANTHER METHOD: This method is used when I want to use the pollen provider also as a mother.
Anthers are removed from the flower by using a sharp pointed tweezers. The stamens are held over the opening of a plastic prescription pill container and pulled loose with the tweezers. I label the container using a small stick on price tag label; I write both the rose's name and the date of collection. If the stamens collected are from only one or a few flowers, the cover can later be used to "ripen" the anthers. When ready to put the stamens in the picnic cooler, just turn the container over, tap the sides to have the stamens fall into the cover, and place the covers in the picnic cooler containing the bag of calcium chloride. Most pollen will mature in 24 to 48 hours. If the pollen has not been released by 48 hours, try crushing the anthers with a flat blade chromed screwdriver. If pollen is then released it shows clearly against the chromed surface of the screwdriver. I then pollinate using the screwdriver to deliver the pollen.
Note, if you are planning on using the flower (from which you have just removed the anthers) as the female parent with another variety's pollen, it is important to remove all of the anthers; check carefully for buried anthers - not all roses have them but some do.
Preferably, the dried pollen should be used immediately. If the pollen must be stored, it probably can be kept for several weeks in a refrigerator or for about nine months to a year in a freezer (this is a general statement - how long a given set of pollen will live depends on the variety and even on the growing conditions of the individual plant). After a week or two of refrigerator storage, you may not want to risk using the then questionable pollen on a variety for which you have only a limited number of blooms. Instead, you may want to use the pollen (by itself or mixed with other questionable pollen) on a variety that you have an excess of. Decide on your breeding program ahead of time so that you will be ready to pollinate roses when the first blooms appear in the spring. Try to pollinate when the plants are actively growing and it is cool enough that the plants are not under too much stress. In general, hybridizers do most of their pollinating during the first bloom cycle. The seed on some varieties will not mature when the second bloom cycle is pollinated, especially in northern climates (although 90 days of maturity is considered average, some varieties may take up to 120 days). Unfortunately, some varieties are not as fertile during the first bloom cycle as in later cycles. Also, some varieties mature relatively quickly (as quick as 60 days); and, for these, even the third bloom cycle may be used in warmer areas.