Monday, July 11, 2011

Hybridizing Daylilies, Step By Step

 Daylily 'Dallas Star,' showing its form and interior.

My friend Blondee asked me to do a blog post about how I breed my daylilies.  Today was a perfect morning to do that, so I took my camera outside while I dabbled pollen around.  Breeding daylilies is ridiculously easy - absolutely anyone can do it.  It makes a great long-term home school science project, too, since any kid can crossbreed them, grow the seedlings, and see them bloom in  1-2 years.

 The stamens (shorter, up-curled, with pollen sacs on the tips) 
and the pistil (longer, with a plain, sticky tip).

Daylilies are very simple flowers.  Each bloom is made up of three petals and three sepals.  Since the sepals are colorful like the petals, it gives the appearance of one, six-petaled flower.  Daylilies have six stamens, which bear the pollen, and one pistil, which receives pollen and transfers the genetic material down a long, thin tube to the ovary of the flower.  The ovary of the flower becomes the seed pod after fertilization occurs.

There are two kinds of daylilies - diploid (having two sets of chromosomes) and tetraploid (having four sets of chromosomes).  They aren't easily distinguished by eye (although generally tetraploids are huskier than diploids, having broader foliage and thicker blooming scapes with bigger, thicker flowers).  They can't crossbreed.  If  you have a mix of daylilies but aren't sure which are which ploidy, plan on making a handful of crosses between different flowers to make sure you get some to successfully set seed.  Most plants sold by box stores now are tetraploid hybrids.  Old-fashioned varieties are more often diploid, taller and with more elegant flowers. (The orange "ditch lily" [Hemerocallis fulva] so common along American roadsides is actually infertile, and spreads by its roots, so don't try to use those for breeding.)  I'm using two diploid, older daylilies to demonstrate hybridizing today:  'Dallas Star' and 'Ida Miles.'

Weather affects your pollinating success quite a bit.  You need a warm, dry morning for the best results.  The pollen sacs will open gradually as the day warms; some plants will open earlier than others.  If the sac isn't fully open and the pollen visibly fluffy, it's not ready.  The flower to the left isn't ready to be used for pollination yet, even though this picture was taken at the same time I was pollinating DS x IM, just before 10AM.  It could probably accept pollen from another flower on its pistil, but its own pollen isn't ready to be used.

Wet weather isn't good, because wet pollen will rarely "take" on another plant.  If it rained the night before, the pollen may still open dry and be okay, but if it's raining while you want to try breeding, your success rate will be low - it's better to just wait for another, drier day.

Chose a flower to be the "pollen parent."  While you can try to breed for specific characteristics, the element of chance is what makes breeding daylilies so much fun.  It's amazing how different the seedlings raised from one pod of seeds can be, just like kids in a family.  One great gardener said, "I just breed pretty with pretty," and there's nothing wrong with that philosophy at all.  So, here's the first step:  using your fingers, gently break off one stamen an inch or so below the pollen sac.

Breaking off a stamen.  
Notice the pollen sacs are wide open, and the pollen visibly fluffy.

Take the pollen to the flower you've chosen to be the "pod parent."  Make sure there's no pollen already on the pistil of the bloom you've chosen (so you know that flower hasn't been pollinated by a bee already).  Gently dab the fresh pollen all over the sticky tip of the pistil.  Cover the entire tip of the pistil; really pile it on.  

 Pollinating - really, really easy.

Another cross - see the pollen all over the tip of the pistil?

And that's it.  Really, I told you it was dead easy to do.  Serious hybridizers will sometimes put a paper bag over the freshly pollinated flower, to prevent any other pollen from contaminating the cross they just made, but I've never done that.  I'm not using rare pollen from expensive flowers, and frankly if you coat the tip of the pistil really well, the chances of a random bee adding enough new pollen to throw off your breeding results are pretty small.

BUT, there's one final important step, if you're keeping track of what you crossed:  LABEL THE BLOOM YOU JUST CROSSED with the pollen parent and the pod parent (in this case, 'Dallas Star' x 'Ida Miles').  Don't remove the flower - let it dry up and fall off naturally.  Here's a picture of another recent cross I made, where I hung a tag with the information right at the base of the flower I pollinated.

If your pollination activity was successful, within a week you'll see something like this on your plant as the flower dries up and falls off:


The new seed pod is under the end of the dried up flower.  A week or so later, it will look like the pod on the right.  Daylily seed pods generally take 60-75 days to ripen, so by the beginning of September (from plants pollinated now) you'll have mature seeds.  Daylily pods are ripe when they start to turn yellow.  You can also gently squeeze them at that time if you're not sure, and if the seams of the pod pop open a bit, they're ready.  The seeds will be shiny black, and about 1/4" long.  Each pod can hold up to a couple dozen seeds, but sometimes you'll get less than that.  If the weather was poor when you hybridized, you might only get a few seeds.  The seeds can be sown immediately if you want to get a head start on next year's season (I haven't done that yet, but I'm going to try it this year with some of my seed), or they can be dried for a few days to a week on a paper plate indoors, then refrigerated in a baggie (in the veggie drawer works well) until you're ready to winter sow them or plant them the next spring.  I've had good results winter sowing them most years.  Most daylilies will bloom for the first time the year after they're sown, but it takes a couple years for them to mature into their final bloom form.  First year blooms are often uneven in form or color, but if it looks good as a first bloom, it will probably be even better the second year.  If it's a real dog the first year, it's your choice to give it a chance for a second year - daylilies can really change a lot for the better between their first and second year of blooming.

Have fun!

A nice, dark red seedling from 2007 - it's a bit darker than this in person.  
It's a keeper - now I just have to think of a name for it.


  1. Thanks! I'm bookmarking this post for future you need to be mindful of the weather the day of/after doing this? For instance would a rain shower or thunderstorm wash away/disrupt the transferred pollen?

  2. I lovely lady.
    I will also bookmarking your lovely Blog.
    I love all your Beautiful flowers and the storys about your garden. Thanks so much for becoming my newest follower on my Blog.
    I hope you have a Great Week.
    XXOO Diane

  3. @Blondee, if you think it will rain the afternoon after you've been pollinating, protecting the blooms would be a good idea - a baggie would be fine, and could be removed the day after. The day after doesn't matter - pollination happens within a very short time of dusting the pollen on.

  4. I mean, the WEATHER the day after pollinating doesn't matter. Sheesh, I can't proofread today.