When Floyd Cove sent their fall sale plants, Guy included his opinion on the subject. I didn't notice it until today but it contains the same message that he has included in the past "DO NOT SOAK"

I am a little puzzled by some of this. I know Guy Pierce grows my favorite daylilies and his plants arrive looking fantastic. I also know I have been told that it is the microscopic root hairs that actually take up the water and nutrients. What has me confused is the tests done with Azoxystrobin showing that a 5 min root soak will give the plants up to a six week time period of protection from rust. I have been soaking all my newly arrived plants while I am preparing everything and getting ready to plant. Now I am wondering if it might make more sense to wait for the three to six week period and do a root drench? But wait, the 5min. soak showed to be effective. I have not had a problem doing it, and actually felt it might actually be helping to prevent some rot also? Not sure Azoxystrobin has any effect at all on root rot. Any thoughts out there. I have stopped the overnight soaking of daylilies due to the little short version of this message that I have found included in my purchases. I have not had any obvious differences shown in growth either way.
EDITED:
After a sort search I actually did find several studies on different plants(not daylilies) showing Azoxystrobin to be effective against root and crown rots.

First, an important qualifier. Since the information was sent with a daylily order my suggestion would be that it is best to follow the instructions, just in case any problems develop for whatever reason.
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Having stated that, there is a great deal of information in the note that does not match what is known about daylilies.

There are daylily sellers and hybridizers who expressly suggest that their plants should be soaked on arrival.

Daylilies do not naturally grow directly in water. However, they are plants that adapt quite well to wet conditions. In their natural populations they are often found growing in mires and moors. Mires are defined as swampy or boggy ground. Moors are boggy peaty areas. They also can be found growing on the edges of rice paddies. At least one daylily hybridizer grows their daylilies in "water beds".
Researchers have determined that daylilies are quite capable of surviving in wet conditions. They flooded daylilies in pots (with different types of soil) three times. For two of those floods the pots were completely immersed in the water for 24 hours.
Other researchers tested daylilies by apparently immersing pots completely and half-way in water for up to 27 days (research published mainly in Korean). This is what they concluded,
"The flooding tolerances of the plants were tested by analyzing their growth status under half immersion and full-immersion conditions, with varying durations of immersion. In decreasing order of flooding tolerance, the comparative analysis of plant height and leaf width is as follows: Hemerocallis fulva, Juncus effusus var. decipiens, Iris pseudoacorus, Phragmites communis TRIN, Typha orientalis C.Presl, Aster koraiensis Nakai, Iris sanguinea, Equisetum hyemale, Acorus calamus. Specifically, Hemerocallis fulva, Juncus effusus var. decipiens. Iris pseudoacorus showed excellent growth status under both immersion conditions. Iris sanguinea and Equisetum hyemale. withered to death by around day 27 of the experiment,"
A third group of researchers also tested the flooding ability of daylilies. From their published work,
"This study investigated tolerance of 15 candidate perennial species,
which experienced flooding cycles consisting of 1-day and 4-day inundation and draining phases."
Daylilies survived both flooding tests 100% and none of the growth measures were affected by the flooding.
Personally, over the years I have placed many dozens of daylilies in pots into our pond during the summers. The water levels have risen and fallen with the weather and at times been above the pot rims. I have never lost any of those plants. I currently have three containers with daylilies that have been soaking in water for many days with no problems (other than having to replace the water every few days because of mosquito larvae).

Separating the two fans of a double fan. If one fan is much larger than the other fan then it is possible that the larger fan is providing the smaller fan with more resources than the smaller fan is providing in return. If both fans are about the same size then they probably are transferring about equal amounts of resources to each other. I divide such double fans and plant them separately. Of course we do not know that joined daylily fans actually exchange any resources but it probably is a safe assumption that they do. Whether any such exchanges benefit smaller fans needs to be examined objectively. Whether joined fans are more "successful" than equivalent separated fans needs to be examined objectively.

It is debatable whether leaves cool the roots. Normally the roots absorb water and it moves to the leaves where it can cool the leaves but is in any case needed for photosynthesis and other functions. When the roots cannot absorb enough water the leaves wilt, etc.

Planting the daylilies too deep. When daylilies are planted too deeply they can extend their "crowns" to the soil surface. I have tested this three times. Once accidentally, when I was hoping to kill a section of a daylily bed by covering the growing daylilies completely with a mound of soil and twice by burying potted daylilies in deeper pots. In all cases the daylilies extended to the surface and grew new leaves. I will have a separate post showing the results of one such test.

@admmad,
Any comments on the fine hairy roots being the ones that take up the water and the nutrients, and the visible roots that come with the plants not being able to take up water and nutrients? Maybe there is some ability of the larger roots to take up water and nutrients, or maybe there are enough fine roots left when the plant is dug to absorb chemicals like Azoxystrobin during a root soak?

@Seedfork
Larry, root hairs certainly take up water and the other material requirements of the plants. Most plant tissues have outer coverings (for example cuticles) to help prevent/reduce water loss. They would also reduce/prevent water absorption. I do not know if daylily roots (not root hairs) can absorb water directly.

I expect (easily proven wrong) that both the normal roots and the crown can absorb water directly.

I do not know how quickly plants regrow their root hairs.

A "rough" test would seem easy (Pat & Sooby will set me straight :-).
Take two freshly dug daylily fans of the same size, including leaves and roots and of the same cultivar. Leave one in the sun in dry soil; leave the other also in the sun but in a container of water (that the sun cannot heat any more than it can the other container of soil). Compare the two plants after an afternoon in the sun. To make it more objective weigh each plant before and after the afternoon in the sun and compare the differences in weight. The two plants should be of approximately the same size to begin with and with approximately the same amount of root, etc.

A simpler test might be to take a daylily fan, remove all the leaves, let the crown and roots dry for a day, weigh the plant (crown & roots), place it submersed in a container of water for 24 hours, reweigh the plant (after drying the surface moisture) - are the two weights different?
Repeat the test with say five plants.

admmad said:
I do not know how quickly plants regrow their root hairs.

A "rough" test would seem easy (Pat & Sooby will set me straight :-).
Take two freshly dug daylily fans of the same size, including leaves and roots and of the same cultivar. Leave one in the sun in dry soil; leave the other also in the sun but in a container of water (that the sun cannot heat any more than it can the other container of soil). Compare the two plants after an afternoon in the sun. To make it more objective weigh each plant before and after the afternoon in the sun and compare the differences in weight. The two plants should be of approximately the same size to begin with and with approximately the same amount of root, etc.

I seem to recall something in the AHS 2002 New Daylily Handbook in the anatomy and physiology chapter that for a period of time they observed that a daylily naturally has no discernible root hairs.

The first problem that comes to my mind regarding the "rough" experiment is that the daylily in the sun may lose moisture but the soaking one will likely be prevented from losing moisture by the water. In that case there would be a difference but it doesn't necessarily mean the soaked one took up moisture as opposed to not losing it. So it would really be important to weigh before and after.

Some people put fertilizer in the soaking water which is something I would not do because if you make the concentration too strong it may draw moisture out of the roots.

A theoretical concern with soaking can be the so-called "water molds" that can cause rotting. They can spread from one plant to another by swimming in water. Of course many of us have soaked daylilies on arrival without a problem so how often this might occur I have no idea. I remember that the late Ra Hansen was very much against soaking new plants.

These days I tend to "park" them in damp medium in a large container instead of soaking if I can't plant them right away.

The section about roots and root hairs is in the original 1968 daylily handbook from the American Horticultural Society. You can download it here, the roots section starts on page 122:

https://ahsgardening.org/wp-co...

I've always thought that article had some great information and some of the best illustrations of daylily growth I have seen anywhere.

Thanks for the link, Sue. I downloaded a copy and will enjoy reading it.

I have run a quick test of whether daylily roots can absorb water after being dug, cleaned of soil and allowed to dry. In digging up a daylily clump for a test, the fan of leaves of one crown broke off leaving the roots and part of the crown. It was discarded on a small pile of grass clippings in the sun. About eight hours later I realized that a crown with roots but no leaves would be appropriate for a test of whether daylily roots can absorb water without living root hairs. I retrieved the partial crown and roots, brushed off obvious soil, weighed it and immersed it in water overnight (12 hours). The weight before being immersed was 89 grams. The weight after being immersed and paper towel dried was 111 grams. It absorbed 22 or more grams of water. It probably absorbed somewhat more water since the soil was originally removed from the roots and crown by dry brushing. A small amount of soil was still on the surface of the roots before they were immersed (left on the roots because I did not want to roughly break all the thinner roots). Some soil soaked off the roots during the night and some was removed during the towel drying.
The sun and air drying should have killed any/all the root hairs. If they were not all killed then the typical or normal process of digging and dividing daylilies for shipment and shipping them would not have done so either.

I have been investigating the common idea that root hairs are necessary for absorbing water. Generally, it seems that both roots and root hairs absorb water. Large roots that have a corky outer surface may not absorb water well but roots without such layers do absorb water.
There has been a recent review of root hairs and water absorption. The full document is not easily/generally available (reading it at a university library may be possible) but the abstract is. I have included the abstract below.
"Abstract
Sufficient water is essential for plant growth and production. Root hairs connect roots to the soil, extend the effective root radius, and greatly enlarge the absorbing surface area. Although the efficacy of root hairs in nutrient uptake, especially
phosphorus, has been well recognized, their role in water uptake remains contentious. Here we review recent advances in this field, discuss the factors affecting the role of root hairs in water uptake, and propose future directions.
We argue that root hair length and shrinkage, in response to soil drying, explain the apparently contradictory evidence currently available. Our analysis revealed that shorter and vulnerable root hairs (i.e. rice and maize) made little, if any, contribution to root water uptake. In contrast, relatively longer root hairs (i.e. barley) had a clear influence on root water uptake, transpiration, and hence plant response to soil drying. We conclude that the role of root hairs in water uptake is species (and probably soil) specific. We propose that a holistic understanding of the efficacy of root hairs in water uptake will require detailed studies of root hair length, turnover, and shrinkage in different species and contrasting soil textures."

From "The role of root hairs in water uptake: recent advances and future perspectives"
Journal of Experimental Botany 73(11):3330-3338, 2022.

I have bolded and italicized the important conclusion. It is quite possible that root hairs are not very important for water absorption in most daylily cultivars.

I also learned that root hairs are quite short-lived. In barley they only last about three days or so. They are continually being replaced.

This all brings about another question I have, but is still in a way related to soaking or not soaking, but more directly related to daylily roots and their
water and nutrient up take by them directly after being transplanted.
I had followed for years the suggestions by many that when you first transplant you should water once then hold off for a week at least, and that no fertilizer should be applied at the time of transplanting, but that should be delayed for at least two weeks minimum and preferably until noticeable growth began.
Then I read here on this site by someone reporting that they had seen faster growth and better recovery when transplanting especially weak plants when they added some fertilizer at the time of transplanting.
I suppose the main purpose of delaying watering and fertilizing was to avoid rot, and as was mentioned by the Floyd Cove post, to avoid burning off any new hair roots trying to form.
So I created 14 new beds along my back fence and bought a slew of plants from club sales and did some trades, was given some plants and got some great deals from some hybridizers and sales here on site and now have those 14 new beds (Sept. and Oct. of last year) filled. Those plants for the most part with only a few exceptions have done very well, showing great growth and performance their first year.
Well, that post about adding fertilizer during the transplanting process stuck in my brain, and most of those plants I added to those new beds I dug deep holes, an idea reinforced by a speaker at our club regional meeting, layered and mixed in compost, native soil, and a mixture of fertilizers (milorganite, 16-4-8, 30-0-10, and a slight amount of pelletized lime). I watered them when the soil felt dry.
I felt the plants did much better with that treatment, but in order for that to be so then the roots would have to be taking up the water and combination of nutrients presented to them. I felt that it was actually stimulating plant growth (leaves and roots) and I was very pleased with the process. I did not lose a single plant to any kind of rot, not a single plant died. I do have one plant in the bunch that has dwindled down about 90 percent, but I am hoping that is due to summer dormancy ( just have to wait and see).
So I am really interested in feedback, water-don't water, fertilize-or don't fertilize. When transplanting is additional watering and fertilizing increasing plant growth (both roots and leaves)-or burning the roots and delaying new growth. Also, does providing all water and the nutrients a plant needs to grow create a weak pampered plant, or a strong vigorous plant?

I suppose the main purpose of delaying watering and fertilizing was to avoid rot, and as was mentioned by the Floyd Cove post, to avoid burning off any new hair roots trying to form.

Root hairs die and are replaced every few days in those plants that have root hairs.
Why would fertilizing plants when planting them "burn off" or otherwise kill any new root hairs trying to form as long as the fertilizer concentration was appropriate?