Hybridizing Tips

Over the summer, I received a number of questions about how to make daylily seed, freeze pollen, etc. and as promised, here are some of the techniques and shortcuts I've found helpful.

The process of pollinating a daylily flower is very straightforward. You simply dab a small amount of pollen from the anther of one daylily onto the stigma of another. As long as you pollinate diploids with other diploids and use tetraploids with tetraploids you can use a long-term master plan or just a spur of the moment decision to create your own one-of-a-kind daylilies. With viable pollen, a fertile ovary and a bit of luck you can set a pod and harvest seeds in 6 to 8 weeks.

The pistil consists of the long tubular style and the stigma at the tip. The stigma receives pollen which travels down the style to the ovary where the seeds develop. The anthers contain pollen at the tip of the stamen -- there are typically six stamens on each flower.	Pollinating a daylily flower. I use hemostats (similar to reversable tweezers) to handle stamens. The hemostats are dipped in water and dried with a cloth before changing to a different stamen to prevent cross-contaminating  pollen from different cultivars.

There is always a chance that the flower was pollinated earlier than your attempt by insects or wind-blown pollen. To minimize this possiblity, I try to pollinate flowers as early in the morning as possible -- before the bees are out of bed and before the anthers have opened for the day. Using frozen pollen (as decribed below) works well as you don't have to wait for anthers to open. I simply make a note of the flowers that will open on the day then select pollen from the freezer to use on particular flowers. By the time I get out to the garden, it's ready to use.

There are some daylilies that produce pods easily, others will produce seed only under certain conditions and there are those that are pod infertile. Before I give up on a daylily I really want to use in my hybridizing, I will try several different methods, such as pollinating the evening before the flower opens, breaking the style into half its length if it is very long, using pollen from cultivars that seem to have very fertile pollen or selfing the flower (by using its own pollen).  It seems that once you can get a tough-to-pollinate plant to produce the first pod, others are often easier.

For difficult cultivars, I make long hybridizing tags that I can make shorthand notes on.  In the photo above, I was trying to pollinate 'Webster's Pink Wonder.' The first two attempts with  'Stick Figure' and 'Topspin' did not work.  The slash beside "SB" ('Stringbean') means I broke the style to shorten the length. The circle beside "FLR" ('Forestlake Ragamuffin') means I pollinated it the evening before and then had a final try with 'Debary Canary.'  Unfortunately, none of my attempts resulted in seeds this year.

Make sure your hybridizing tags are attached at very base of the flowers as close to the scape as possible.	It's really disappointing to lose tags of a cross you were counting on. This tag will fall off with the flower because it was not properly placed.

The tags I've found to be the best for my purposes are homemade using vinyl mini blinds (you can pick these up at garage sales for a song) cut to the size I want.  A sturdy hole-punch that accepts several tags at once makes quick work of the holes and the wires are green plastic covered wire garden ties available by the spool. I've never found a problem with sun fading using a fine point "Sharpie" marker.

Seed pods will begin to brown as they ripen.	Seeds are mature when the pod softens and cracks.	But if you wait too long, the seeds can tumble out. You can tie netting or a piece of pantyhose over ripening pods if you are unable to harvest them before they get to this stage.

Freezing Pollen

Almost all of the pollen I use is frozen. Most of the new daylilies that arrive from the southern US bloom well before our season begins here so it's great to have a ready supply of pollen when I need it. I have used tiny centrifuge tubes and empty gel caps for storage, but they are really fiddly and hard to write on. This year, I came up with this storage method which has worked very well:

Items you need: Plastic food wrap, a hole punch, 4" lengths of vinyl mini-blinds and cotton swabs.

Using a swab, gently brush and/or tap the anthers so the pollen falls onto a square of plastic wrap. Working on a dark surface is helpful.	Roll cotton swabs over the pollen until they are covered.	Cut swabs in half.

Each swab is rolled up in plastic wrap with a some excess on the end to form a "tail."	Two holes are punched in mini-blind pieces and each is labelled.	The "tail" is folded over to seal the swab and then inserted into the two holes.