Sue, how hot does it get up there in Ontario, Canada anyhow?
You are correct about raising mowing height. That way the grass can shade itself.
I never mow less than 4".

I live in Florida and NEVER water my St Augustine lawn or even my Bahia grass lawn.

I also have trees that provide shade at various times of the day. And that helps keep the yard cooled off.
Most of my daylilies get afternoon shade, and I notice many have set pods they wouldn't do if too hot.

I have also been told that when new plants are dug some of the roots are damaged so it helps to cut back on the foliage, but I was also told that once you see the first bloom and establish that what you bought is correct you should actually cut the scape out then. I have never been able to bring myself to do that and the daylilies seem to have done just fine. I can see that it might actually be best for the plant. I think most people assume that the foliage is cut back to make shipping easier, and I am sure that is part of it, but also I think the leaves are cut back to help prevent transpiration.

I have heard that too but I have never cut scapes off. Can't bring myself to do that.

[quote="Xenacrockett"]Sue, how hot does it get up there in Ontario, Canada anyhow?

In July when most daylilies bloom it can be 86-97 degrees F in the shade on some days - would be in the low to mid-80's more often. Not as extreme as those of you in more southern areas of course! Winter lows can go down to the -20's to -30's F so quite a range (hence all daylilies are winter dormant here).

I just won an interesting booklet on eBay. "Growing daylilies in Queensland" M. Chantrill 2001.

"When blooming is finished, the foliage may be cut back to a height of 20cm This is believed to stimulate the production of new fans." What you think?

Well, I have no experience with that, but I think it does sound possible and maybe worth a try with certain varieties.

Gleni said:I just won an interesting booklet on eBay. "Growing daylilies in Queensland" M. Chantrill 2001.

"When blooming is finished, the foliage may be cut back to a height of 20cm This is believed to stimulate the production of new fans." What you think?

I have seen no evidence of this. We cut ours back every year at the end of season to either move them or the ones that aren't getting moved to help so we can replenish the fertilizer, alfalfa, and whatever else around the clumps and I have not noticed any increase in fans by doing so. It may just be that the daylily is no longer putting it's energy into blooming and can then put it's energy into increasing. What we do at the end of our hybridizing season is cut the scapes off so they will no longer bloom and put energy into blooming (that don't have pods) and this will help the plant increase in fans. Stamile is the one that told James Hall about doing this and said that is what he did.

Sounds like you've given me some great summer experiments to get underway soon, and I am eager to try them out! Some fans are already showing signs of early dormancy, and I'll hate losing all the buds that are on scapes if it dormancy gets into full swing too soon here. And, If I can save one cultivar from retrograding fan and root size during the regular dormancy months of July through August, it will be one less that may succumb and have to get tossed or, at best, sheltered in my tiny greenhouse over the winter just to rebound at juvenile size (one step forward, two back).

I will try:

1. Leaving some to naturally go dormant with full foliage.
2. Trim some back to about 8 inches (thanks for the 20 cm recommendation).
3. Try to rig a shade cloth over a few.
4. Have one set that gets less frequent but deeper watering (I've heard this helps grass avoid rust, too ... ?).
5. Have another set that gets regular watering along with regular leaf spray treatments.

If anyone else has other ideas ... there are enough cultivars "to be culled" from my gardens this year that learning how to manage summer losses and setbacks from dormancy would be a great use of my time.

Follow Up: I think my experiment may have already mostly done itself due to the run of 104-to-106-degree days we just had. I'll explain the pictures, but it seems that my daylilies really do need supplemental shade to avoid stress and perform at their best in my 9b garden. The sun is direct on my "blast furnace" garden from about 8 am to 4 pm, so they get 8 hours of full sun, with an additional 4 hours of indirect rising or setting sunlight (mostly blocked by neighboring houses and 6-foot privacy fences).

Potted and trimmed daylilies in shade did great even with soil that quickly dried out, perhaps because the shade reduces temps by about 20 degrees (down to 85-90), and sun exposure by 50% or more from lattice on the roof and sides of the patio. Those planted in-ground in the deep shade garden, and between two shading bushes, also fared well without or without trimmed foliage.

But, the untrimmed fans in the blast furnace garden did not seem happy at 106 with no shade. And, like Sooby mentioned, trimming might have left them even less able to withstand the heat and sun.

All plants receive approximately the same amount of watering, with an extra pass given to the 106/blast furnace garden. That soil stays just this side of moist, with a finger poke that tells me there is cooler, well drained soil under dry topsoil. If I'd trimmed foliage, the browning and curling-up of leaf blades would perhaps have just gone even deeper in toward the crown. But, leaving them uncut and exposed to full sun for eight hours is still putting them under much more stress than plants 30 feet away that enjoy the shade of patio, bushes, or trees.

Potted, trimmed plants at the side of the patio, temp reduced to approx. 85-90 degrees by 50% shade provided


Potted, trimmed plants on the patio under latticework, temp reduced to approx. 85-90 degrees by 50% shade provided


In ground, trimmed plants flanked by bushes on either side, temp reduced to approx. 85-90 degrees by 50% of shaded provided


In ground, untrimmed plants shaded by trees and buildings, temp reduced to approx. 85-90 degrees with 80% or more shade


In ground, untrimmed plants in blast furnace garden, 106 degrees and unshaded during eight hours of full sun. Pinks, Carnations, Sea Thrift and Cactus all stayed fully green.


Thanks for letting me try this out. I can tell now that trimming foliage (or not) will provide little or no protection for my full sun daylilies. I can also see that providing them with 50% shade cloth coverage, as soon as temps go above 90-100 degrees, might help them avoid the stress of heat dormancy. I'll work on setting up a retractable clothes line, strung with shade cloth, to pull over them for next summer. As always, though, if anyone has cautions or thoughts about other ways to provide them protection from full sun, I'd be interested in hearing about it. However, planting trees or bushes in the blast furnace beds is not an option for me - so that alternative solution would not be possible in this case.

Very interesting experiment and quite a difference in appearance between the two groups.

Without a doubt the ones in the shade do look much less stressed.