Saturday, August 18, 2012

Pollinating Roses

I've received numerous inquiries concerning how you go about creating your own rose hybrids. First, let me share with you there are many ways to accomplish this. What I am about to share with you is simply what has proven successful and easy for me. It isn't meant to be taken as the ONLY correct way to do this as there are many different ways to succeed.I try to make it as easy, simple, uncomplicated and CHEAP as possible! Please feel free to make it as easy, or complicated and expensive as you desire.

Tools and Supplies...

Once you have come up with ideas of what roses you wish to cross, and decided which you wish to use for seed and which for pollen, you will need to both collect and process the pollen, and prepare the seed parent blooms. Nearly twenty years ago, I was fortunate to have my sister save me all the baby food jars she generated raising her new baby. I still use those 'antique' baby food jars to collect and hold my pollen. People have also successfully used the plastic film containers 35 mm photographic film was packaged in. Any small, inexpensive, durable, easily obtainable containers can be used. I like the baby food jars because there was a great supply of them at the time; they last until you drop and break one; I can run them through the dishwasher when needed; they're clear, so I can see into and through them easily; and they fit my hands perfectly. 

You'll also need something to cut the anthers from the blooms to collect them for pollen. I know some who use curved tweezers to pull the anthers from the blooms and they like them. I've also heard of some using an Xacto Knife to cut them from the flowers. Any small, sharp scissors work OK, but these tweezer action, needle point sewing scissors have been a tremendously easy, inexpensive tool for me. You can easily find them on line or at sewing stores for under $10, under names such as "Squeezers", Easy Cut and Spring Action names. They're small, light-weight and easy to handle with one hand, making them very useful when trying to extract anthers from a flower still attached to the plant.
Unless you don't care what went in to making the seeds you've created, you will need some method of marking the hip so you'll know who the parents were. I generally don't want to use a rose for breeding unless I can research what made it, to make sure I'm using genes which have proven themselves healthy and vigorous where I grow roses. While not absolutely necessary, I'll bet you there will come a time when you wish you had kept track! 

There are several ways of marking a cross to keep track of the parents. If you are only using a small number of pollen parents, you can use colored string, ribbon or yarn, a different color for each type of pollen. Just secure the appropriate color around the peduncle of the hip to keep track of which belongs to what "daddy". I've read of one gentleman who used telephone wire with its many different colored smaller wires inside. He assigned each color to a specific pollen type, going so far as to combine colors for the ones which exceeded his number of single colored wires. Of course, you will need to keep a list of what color indicates what pollen parent, but that is a very unobtrusive, durable method of marking the hips. Still others use colored plastic tape or ties, even writing the cross on the tape before tying it around the stems. Anything which permits you to keep track of all the information you wish to keep track of which lasts as long as you need it, is fine. 

My personal choice is to use paper string tags available at many office supply sources as well as on line. 
 It's difficult to see through the glare, but the model number of the tags is 12207. This size is large enough for me to write the name of the pollen parent on it and the looped string permits me to easily attach it around the peduncle while pollinating. Unless a snail or slug eats the tag, as long as it doesn't sit in the soil, it lasts long enough in my garden to permit me to collect it with the hips when it's time to harvest the seed. At that point, they look like this. 

Of course, only writing the name of the pollen parent on the tag means I have to keep track of which ones came from what seed parent, but that has seldom been an issue. You may write the full cross on the tags if you desire. 

Down to Business...

Some roses begin releasing their own pollen on their stigmas as soon as the sepals begin to separate and the petals begin showing color. I learned from Natalie Anderson at Texas A&M University they don't follow the old, established instructions of preparing the seed parent and waiting for them to mature, when the stigmas appear wetter and sticky. She reported that the pollen can be successfully applied as soon as the flower is prepared and pollen is ready. She was right! I began following that method this year and, if anything, the success rate increased over previous years. 

Select which variety of rose you wish to use for a pollen parent. You may either remove the flowers used to donate their pollen if you don't also wish to use it for seed with other pollen, or leave these blooms attached to the plant for pollinations. Some people cut off the sepals as it often makes it faster and easier to attach the tags and accomplish the pollination. Some rose types won't fertilize and set seed if the sepals are removed. Many others, will. It's your choice whether you wish to remove the sepals or not. The one benefit I can see of leaving them is, some varieties' sepals fold back as the flowers open and remain folded back until the hip is ripe. At that time, the sepals will actually turn back up and poke out away from the top of the hip. 

Either remove or fold back the sepals to expose the petals. You can often firmly grab the point of the petals and wiggle them back and forth to break the petal bases free from the ovary. You will probably also loosen quite a few stamen and anthers in the process and lose them as you remove the petals in one, folded mass. You may also peel off each petal individually to finally expose all of the stamen and anthers. 

To collect these stamen and anthers from this bloom and leave it on the plant so it can also serve as a seed parent, I hold a baby food jar in my left hand (I'm right handed) and place it just under the bottom edge of the ovary. In my right hand, I hold the tweezer action scissors, then begin carefully cutting through the stamen where they attach to the ovary, collecting them in the baby food jar under the bloom. This is where the squeeze action of the scissors I showed above really comes in handy! It doesn't require your thumb and another finger to operate them, you just squeeze them together and they cut. What results looks like this. 

With something like this in the baby food jar. 

Drying the Pollen...

Ideally, you have somewhere warm and dry, where there will be no strong breezes from windows, doors, fans, etc., where you can spread the anthers out on pieces of plain old paper. If you've collected the anthers in the morning hours and your day is hot and dry, spread out on a piece of plain old computer printer paper (what we USED to call "typing paper", I know, I'm dating myself!), the pollen can actually begin releasing from the anthers by mid to late afternoon. The cooler and damper it is, the longer this will take. You don't need full sheets for each one, unless you've collected a bucket full. I've cut them into small pieces just large enough to hold small quantities, and even used index cards for drying. You can see the pollen releasing from the anthers as they dry. It will appear as a colored (usually) "dust" when you gently shake the pieces of paper. At that point, I carefully dump all of the material back into the appropriate baby food jar.

Unfortunately, from experience, you want to put your pieces of paper out of reach of the house cat. Fur makes an EXCELLENT "brush" for pollen! Several hours of effort can be wasted by one "brush" with the cat's curiosity!

Once back in the jar, I grasp it with the palm of my hand over the opening and shake it side to side to help release the pollen from the dried and drying anthers. You will see the pollen sticking to the sides of the jar like this. 

As mentioned above, as soon as the seed parent bloom is "emasculated", has the anthers and stamen removed like this...
you may begin applying the pollen. 

There are as many methods of applying pollen as there are each other step. Some use Q-Tips; some use small brushes. I simply use my finger. I swipe my finger through the pollen on the jar sides
and gently massage the pollen into the prepared stigma. Watch bees when they "molest" a flower. They are anything but gentle! You don't want to squash the stigma, but you do want to get the pollen transferred to all of the stigma pads so you create as many seeds in each hip as possible. The stigmas are actually more durable than you imagine. Don't let them intimidate you, but don't bruise or smash them. Just firmly, but gently work the pollen into the stigma until it resembles this. 
Tag the bloom, and you're ready for the next one. 

It can sometimes be difficult to see if there is enough pollen applied because not all pollen is the same color. It can range from golden, through light yellow, to white. Basye's Purple Rose actually has purple pollen. It looks rather dirty, but it works. Sometimes the pollen from Burgundy Iceberg can be almost as purple. If you don't have much pollen to spread, making sure each flower used as seed parent is flooded with pollen can be more efficient than trying to pollinate more blooms with less per bloom. 

Pollen varies in size and that can make huge differences in how fertile it is with other roses. Flooding each bloom you pollinate with pollen, making sure as many of the filaments of the stigma are thoroughly coated with pollen, can result in many more seeds per hip, giving you much more bang for your buck. Ideally, you want to pollinate the blooms when it isn't expected to rain on them for about two days to give the pollen the chance to fertilize the ovaries before being washed off. Some actually make paper or foil "caps" to put over the flowers to prevent any rain or sprinkler issues. 

Once you have applied all of one kind of pollen and are ready to switch to the next, clean your finger or brush, or pick up a new Q-Tip. If you don't use any pesticides or fungicides on your roses, you can even just suck the pollen off your finger. You can wash your hands or just wipe the pollen off with Rubbing Alcohol and a paper towel. I'm told if you use brushes, the alcohol is excellent for cleaning them between each type of pollen. You CAN wipe your finger on your clothes, but some of them can stain badly, so be forewarned. 

Generally, you may begin pollinating as soon as you have blooms of what you wish to work with available. Because it usually takes up to three months for the seed to ripen, you probably want to stop pollinating at least that far in advance of your expected first frosts. I COULD pollinate virtually year round in my climate, but find the best time for planting where I am is late November. I stopped pollinating about the first of August to give the remaining hips the desired three months before optimum planting time here to ripen. 

Now, You WAIT...

Rose hips are actually fruit, closely related to apples. Like apples, hips can take on many different colors as they ripen. Don't be concerned if you don't see them turning the expected reds or oranges as not all varieties of roses color their hips brilliantly. Some do, but not all of them. Many are just fine and remain green. Some species actually turn black. Generally, the seeds are viable after two and a half to three months from fertilization. If you're lucky, nothing will have knocked them off or eaten them before then, so you can have the excitement of harvesting your crop of potentially beautiful new rose seeds. Many "garden visitors" LOVE eating rose hips! During WWII, when Britain was experiencing large outbreaks of scurvy due to the lack of imports of fresh produce, it was discovered the hips of their native roses contained up to 25 times more Vitamin C than oranges and up to 60 times more than lemons! Now, you understand the benefit of teas and vitamins with "rose hips". The seeds can be rich in other vitamins and all sorts of rodents appear to be very well aware of that. Squirrels, rats, mice and rabbits LOVE rose hips and rose seed!

Because of the "garden visitor help", I began harvesting hips a few weeks ago in hopes of getting to the really experimental ones before they were eaten. I shelled the seed, removing them from the hips, and storing them in small zip lock type plastic bags with tags containing the cross information written in pencil instead of ink. Graphite has to be rubbed off. It doesn't dissolve in water, nor fade with heat and light. The bags of seed are stored in the refrigerator to keep them chilled, potentially delaying any from germinating until the weather is more conducive for them to germinate. Generally, better germination occurs at temperatures which remain lower than about seventy degrees. Spikes into hotter temperatures may slow germination, but once the cooler temperatures arrive, it resumes. They also germinate better when it rains. The seeds and seedlings seem to know the difference between rain and hose water.


 You may plant in many ways and may have to experiment with several to see which is better for your climate and gardening style. Many use pots. Where I am, it is very hot and dry. Pots overheat and dry out rather quickly. What I have found works best for me here are boxes, made of plain old 8" wide, fir fencing boards. I have two boxes, 2' wide, 4' long and 8" deep, filled with moisture control potting soil. I use moisture control because it doesn't dry out as quickly here in the heat. It may be too heavy and wet for you if you live where it is cooler, damper and actually have RAIN. My inexpensive, easily made boxes rest on saw horses where they receive sun most of the day. 
The sides are screwed together. The bottom has half inch, galvanized hardware cloth and nylon window screen stapled to the box side bottoms. The box is then rested on two, 2" X 4" lengthwise with smaller pieces of wood attached to them like rungs on a ladder, to support the bottom and prevent the soil from falling out. I water with the hose and a soft rain head. Drainage is perfect! 

The tags are always put at the same end of each row for uniformity and to make it easier for me to keep track of what seedling belongs to which cross. The separations between the rows are simply thin bamboo stakes cut down to the appropriate size. The seedlings will remain growing in the boxes until the rains begin in fall, when I can safely transplant them into individual pots. Once emptied, I will refill them with potting soil and plant the seeds of this year's efforts. You can just see the box lid at the upper edge of the box. To prevent critters from getting into the boxes and eating the seed and seedlings, I created a frame of 1' X 1" wood and stapled plastic hardware cloth to it. The lid is slightly larger than the actual box, so it slips down over the sides and rests on screws partially driven into the sides. Think shoe box and its lid and you have the idea. This prevents entry to the box, but permits air, light and water to flow through without issue. Once the seedlings began growing through the lid, I removed it. 

I hope it helps make pollinating less "mysterious". It really isn't brain surgery or rocket science. I mean, BEES have done it for eons! It can be a lot of fun and you just might raise something quite good! If nothing else, you will see baby roses flower in your garden, no one else in the world has ever seen!


  1. You did a great job of explaining the whole process, Kim! Thanks again for taking the time to educate! I am wondering if there are any detrimental effects if one leaves the hip intact in the frig. I have thought from some other comments I have heard that others may leave the hips intact and remove the shell when ready to plant, so am curious if there is any benefit one way or the other as to when the outer part of the hip is removed. Are you using the water retentive Miracle-Gro product for your soil mix for germinating seed? I have had a good deal of trouble keeping the soil moist enough to keep seedlings growing, but not so wet they begin to damp off. Jim has promised me a planting box like yours! Thanks again for your helpful blog!

  2. Hi Sally, thank you! Yes, there is quite a bit of evidence the hip flesh contains germination inhibitors to prevent the seed from trying to germinate until they are freed from the hips. There is also evidence that leaving them in the hips until they are fully ripe can delay germination. Harvesting the seed a bit before the hips either appear ripe by color or the stems begin to yellow and release seems to permit earlier, faster germination.

    Some people do leave them in the hips until planting. LeGrice wrote in Rose Growing Complete, he left the hips intact until spring when they had rotted and made cleaning the seeds easier for him. I extract the seed immediately from the hips to prevent having to deal with the rotten hips, which can be nasty. Though probably nothing harmful, I don't relish breathing any moldy spores from fuzzy, mushy, rotten hip flesh while I attempt to find the tiny seeds in it. Yuck!

    I've usually used the moisture control soil until I tried Super Soil this year. What a mistake! Nasty, terrible product, Super Soil! I'm planning to use the moisture control soil this year, but with the top inch or so amended with either more perlite or seed starter mix. I want to loosen the texture of the soil to make it easier for the seedlings to emerge.

    You'll love boxes like these. They make it so much easier, especially if you raise them high enough so you simply stand at them without having to lean or bend over. I will probably need to make larger ones for this year. I kind of over did it. I still have quite a few hips left to harvest, which aren't mature enough to pick yet. Without them, there are already 178 crosses stratifying in the refrigerator! Add the few which have been sent to share with me and there are way too many!

  3. Thanks for the info on the hips, Kim. I will remove the seeds from the hips I have harvested at once--less daunting to do a few at a time in any case! And I will get some of the moisture control potting soil as well--thanks for the tip on the perlite layer too.

    We were so busy earlier this summer that most of my crosses are pretty new, so I will be harvesting later & planting toward spring. Our winters are usually mild enough that I am hoping these late crosses will ripen over winter. When I started the process I realized the timing was not great, but it was a "better late than never" situation with nothing to lose but a few hours of my time.

  4. You're welcome Sally. I completely understand doing "bite sized chunks" rather than a bucket load at a time. I remember Laurie Chaffin, of Pixie Treasures Nursery, telling me years ago she continued pollinating through Christmas because the hips would ripen just in time for her to get the seeds planted. There in Yorba Linda, and with her greenhouses, she could handle all of that year round. I find it easier for me to plant around Thanksgiving (presuming it is cool enough and the rains have begun) and letting Nature keep them watered for me. They're going to require a period of time in the soil, cooling and warming and remaining damp to stimulate germination. I've found getting them under soil around then has many of them germinating long before it gets too hot in late spring to summer.

    The "perlite layer" should probably be a mixture of the types so there isn't a really dramatic difference in water retention. You don't want the seedlings to dry out quickly, just for the soil that covers them to be loose enough for them to come up through.

    1. The first year I tried hybridizing I planted in late fall (before Christmas) and the seedling popped right up. However, I had to keep them under the edge of a roof so they didn't get too much water so they were soggy and cold all the time. I lost most of them trying to remember to check them for dryness, but not keeping them too wet, so maybe up here with the colder, wetter winters early spring might work better for me anyway.

      Thanks for the tip on the perlite--I tend to be a "too much/too little" kind of person :o) By the way...meant to ask where you purchased those handy-dandy little snips--I looked at the craft store but didn't see anything as lightweight and nice.

      Thanks, Kim!

  5. As long as your medium drains well but retains moisture, you shouldn't have too much worry about it being over watered. I try to keep mine out where they will receive any rain we get and all the sun possible, when there is any. You can plant in spring, if you can keep the seeds from germinating prematurely in the refrigerator. That's why I plant in November. If they germinate quickly, great! They're where they need to be so they can just grow. If they don't, that's OK, too. They're where they will germinate when they're ready and the pressure is off me about it.

    The scissors are actually sewing scissors. You should be able to buy them anywhere sewing notions are sold. Here are a few links to some on line.