NEW QUESTIONS:
"I've no clue if they may be Too dried out and in need of some water-only-soaking or not "
You will know if they are too dried out. Usually 24 hour drying in the shade will not over dry them, but if they look like the daylilies that come in the plastic bags (from big box stores) then they probably are too dry
"- I know for garden-to-pot diggings there are both professional and hobby hybridizers who, after initially placing a display/fan in the field/garden, decide to bring it back in under shadier conditions to ensure better pollen production and pod setting (very difficult over 90 degrees in-ground). Any other reasons or reasons-not-to? These might include advice about a plant that is struggling or diseased (like possible early stage root rot) that the owner wants to tend to more easily and directly, or cautions against it?"
I have taken a daylily that was in ground that had crown rot issues and after I soaked it potted it up. One reason is I did not want to replant in the same area for the rest of the season and another is so I could easily keep drenching it with the solution and I knew it would go into the soil with the roots and crown instead of maybe running off away from the plant.
Some people decide to pot theirs up so they can be moved around. Fred (spunky1) does this with his display area daylilies (or did), they are in pots that are in another pot in the ground. That way if he wants to change them out yearly or whatever he just grabs the pot out and puts another one in.
"- What are some visual signs that a potted plant needs re-potting (pale or rapid browning of foliage, pot soil dries out too rapidly, etc.)? For fans already established in pots, is it better to take the plant out to check on roots if one is not sure about it needing dividing, or is it better to divide before that root-bound stage is reached? Three to five years between dividing established potted plants is a good rule of thumb, but with such variety in size, growth-rate and time-to-increase, it would be great to hear some thoughts on other ways to evaluate when dividing is called for. "
I find that if a plant gets root-bound the soil that is in the pot (which the roots are usually all wrapped around) cannot get ample water and if you take the daylily out and un-bound it you will usually find the soil is bone dry. That is why a lot of times the pots need to be watered to get the soil moist and then gone back and re-watered so the soil soaks up the water. I'm sure most people have seen this when a pot is watered and it just seems like the water runs out the drain holes and doesn't get to the plant at all. This is either the soil is way to dry or it is root-bound. Usually the result of this is yellowing/browning foliage, plant shrinking, looking like it is going dormant (summer dormancy for the non-dormant)
It really depends on the growing zone on how long a plant can stay in a pot. If I start out with say a DF and put it in a big 5 gallon pot (keep in mind I use the black nursery pots) I may can go 2 years without messing with it but normally I really would need to divide and repot EVERY year here unless it is a really slow increaser. I have had plants in pots that I was giving to my club and what I have noticed is if it is to root-bound or too crowded fan wise then the fans tend to shrink and there is less scape production.
One sure way to tell if a plant needs to be repotted is the roots are busting out of the pot (I have had this happen) or the sides of pot are bulging. I have had to actually cut the pot from around the roots because I could not get it out. I know some pots will not do this since they are really sturdy and thick walls. If in doubt, I would lift the plant from the pot (if possible) and check the roots. Most of the time people will be able to tell without this due to poor performance, etc. After awhile you will just know which ones need to be done when. Another way to check is if you can stick your fingers down into the pot (in the soil) with no problem they should be ok. I have had some pots that I couldn't even get the plant marker into the pot because the roots were so bound.
"- Is it best to leave all repotting until a certain time of year or temperature range, if possible, or are DLs generally hardy enough to handle repotting year-round as long as temps are not extreme?"
Usually it is best to do this in the fall. We do all of our potting starting in Sept. Sometimes we may need to do some a little before that but if we do we try to sit them in a less sunny spot and we definitely soak them first. Now some people in colder climates who don't want to chance losing any to winter may want to do it in early spring or even in the summer if their temps are NOT extreme. Some zones don't get over 80 in the summer so it would be ok to do it. I wouldn't advise doing it in 95 degree or higher temps unless they will be put in the shadier spot. The hotter the temps the greater chance of rot issues (in my experience).
"As well, I'll add in that the bleach- or peroxide-solution might be used after soaking the fan/s to clean and disinfect the tools and the new or re-used pot."
GREAT IDEA
"- What about blooming or re-blooming? Will trimming always mean that it will be a year before you see another bloom? If repotting a rebloomer variety after a first summer bloom is already done, might you see a rebloom the same summer, or will it take a few months or a year to re-establish the foliage and send up a scape?"
No it does not always mean it will be a year before you see bloom. I really think it depends on what zone you are in and when it is done. There is 2 sides to this and some will say that trimming the roots affect the growth and blooms while others say the ones that they trimmed the roots did better than the ones that they didn't. Someone ( I can't remember who) said that short roots equal short scapes so you may end up with shorter scapes on first bloom scapes. Of course I see this anyway even without cutting roots so who knows.
Some plants will send up a scape right after being divided and roots cut while others wait until the following season. I can't tell you how many plants we divided last Sept that sent up new scapes about 2-4 weeks after being potted. usually these will of course not be full size scapes or the full bud count, etc, but some will surprise you. I'm sure there are zones that it will take a year to get re-established and may not see bloom for 2 years but I really don't know.
"- Do you fertilize after repotting (slow release or mild liquid solution or just use new amended/soil, etc) after re-potting? "
YES YES YES--- we add all the things to the pot that we feed the daylilies. We add alfalfa pellets, chicken litter (dry processed chicken manure). slow release fertilizer, and a quick release fertilizer. We usually go back and add Epsom salt as well. We will then continue with our regular fertilizing schedule of water soluble fertilizer (Miracle-Gro, Daniels Plant Food, or the likes). We re-use our soil but the nutrients are pretty much depleted when we get to the point of potting.
