Hybridizing Daylilies

Gulf Coast Daylily Society of Southeast Texas










By Harland Merriam, February 2008 (updated June 2008)

I'll admit I am a relative newcomer to hybridizing compared to the likes of Jack Carpenter, or the Stamiles, or the Trimmers or others.

Dan Trimmer and Matthew Kaskel of Florida have mentored me with some ideas about hybridizing which I am applying here in Southeast Texas.

Kaskel Daylilies from Kaskel Farms, Inc.
Dan Trimmer's Website (click on image to go there) Matthew Kaskel's Website (click on image to go there)

1.  SET A CLEAR GOAL.  Both Dan and Matthew were very assertive in demanding that I determine what my goal was in hybridizing.  They asked about plant qualities and flower qualities and other very specific objectives.  I realized, as I have in other parts of my life, that if I don't know where I am going, I am not likely to get there.

My goal:  I will hybridize high-percentage polytepal daylilies, both diploids and tetraploids. My objective is a highly rust-resistant, evergreen daylily that will tolerate the heat and humidity of Southeast Texas.  This foliage on this daylily will be upright and well-formed, a vital blueish green color and will multiply at a moderate rate from year to year.  The scapes will set flowers above the foliage, with several branches and 16 or more buds per scape.   The plants will rebloom. 

I have chosen to allow rust to remain active in my garden and do not treat it.  This allow me to subject all my seedlings to rust and see which ones are resistant.

2.  SAY "NO".  In order to say "yes" to the above goal, I will be ready to say "no" to many, many new cultivars that do not achieve or advance my movement toward this goal.  I will simply not have the time or the room to spend with plants that do not move my efforts in this direction.

3.  START WITH GOOD BREEDING STOCK.  Doing good research on those who have already advanced in the direction of my goals and choosing cultivars which have the kind of genetic predisposition to take me toward my objective is important.  I have collected over 30 polytepal varieties, including some of the most recently developed.  Dan Trimmer reminds us that the most important element is color.  Color, color, color!  He recommends picking cultivars that have the absolute best qualities -- fans, scapes, buds, branching, vigor, spacing of flowers, and outstanding blooms.  Choose parents with great flower color -- pure, deep, lasting, crisp, bright. 

4.  KEEP GOOD RECORDS.  One of the keys is good records of pod and pollen parents and of seedlings.  I keep mine in a clipboard notebook, with notes taken throughout the growing season.  I also use the software "Flower 2008" to keep records.

Click to download a PDF File of Harland's PowerPoint Presentation for the March 2008 Gulf Coast Daylily Society Meeting  HOW HARLAND HYBRIDIZES



Since I live and grow on a relatively small city lot, I have chosen to plant my seedlings in one-gallon pots.  There are advantages and disadvantages to this.  The main advantage to me is the control of space.  When a plant does not meet the above criteria, I remove it completely and easily readjust the remaining pots.  Examples:  plants that get rust, plants with weak or poorly shaped foliage, or plants with no rebloom...

I make evaluations and take action based on results after the first year of growth.  Many of the first-year plants can remain in these one-gallon pots for a second year.

Those that pass the test are transplanted into five-gallon pots or into planting beds for further evaluation and multiplication.

Although most of my daylilies are grown in flowing garden beds throughout the yard, I have established a "small nursery" area in my backyard, with overhead sprinkling for my seedlings.  I have placed a woven fabric groundcover under the pots.

My potting formula is the following, for 3 cubic foot recipes:

  •   2.0 cubic feet of "Bruce's Mix" (hard and softwood bark fines, rice hulls, and wood ash from paper mills).  You could use finely shredded pine bark.

  •   .5 cubic feet of sand  (this is a 1 to 4 ratio of pine bark to sand)

  •   4 cups of perlite (keeps it loose)

  •   4 cups of peatmoss

  •   1 cup of bonemeal

  •   1 cup of bloodmeal

  •   1 cup of fishmeal

  •   1/2 cup of milorganite  (as you can see, I appreciate organic fertilizers)

  •   1/4 cup of gypsum

  •   1/4 cup of agricultural lime  (could require more -- see note on ph below)

  •   2 tablespoons of sulfur (could require more -- see note on ph below)

  •   1/4 cup of epsom salts

  •   2 to 4 cups of alfalfa pellets

VERY IMPORTANT:  Check the ph of your mix and adjust up or down.  If it is too acid (too low a ph) as mine was, you will add ground limestone, as per directions, until the ph is back in the 6.5 - 7.0 range.  If it is too alkaline (not likely), the addition of sulfur will rebalance the ph. This may take several weeks for the ph to come back to a stable level.  As we know, the ph of the soil in which the daylilies grows is critical.  If the soil is too acid or too alkaline, the plants will not be able to take up the nutrients (nitrogen, phosphorus, potassium, etc.).  I learned the hard way with 1000+ seedlings, of which only about 3 set scapes, when the ph was too acidic.  After adjusting, the plants flourished.

NOTE:  Dan Trimmer is using a large quantity of an organic supplement from Alpharetta, Georgia, 1 quart per 5 gallon pot, which has alfalfa and chicken meal as main ingredients.  He noted how this formula greatly increases the number of fans set by the seedlings.

I like hands-on learning, so I made my own, mixing ingredients on the concrete driveway, first mixing together the larger quantity items (Bruce's Mix, sand, peatmoss, perlite).  Then separately mixing together the smaller quantity items in a pale and dusting the first pile and thoroughly mixing all of the components of the potting mix.


I've tried for years to get my tetraploid daylilies to set seeds, with little success, something like one or two out of a hundred attempts.  Then Dan Trimmer taught me what to do.  The temperatures here in Southeast Texas get into the 90's before 9:00 a.m. and it too hot for them, he says.  So, bring them inside to the airconditioning!

I pot up my Tetraploid Daylilies, those I want to hybridize as Pod Parents.  On the day they bloom, I bring the pot inside to an air-conditioned porch and do my hybridizing.  The key is to get the plants under 80 to 85 degrees. 

I use a 3 gallon pot, which makes it still manageable to carry in and out. With this technique, I am able to get a high percentage to set seedpods.  I take the pots back outside the day after I dab pollen.  They are inside for only one day.

It may be the romantic music playing inside or the scented candles, but Dan says it is the temperature.  Some others use shade cloth in the garden to get the temperatures down to help set seeds.

Any comments? Click here to email a comment to  Harland Merriam