Definitely NOT rust. I see something similar on some of my daylily leaves. I think mine is the residue of thrip damage as the leaves are dying. (Being sucked dry by the thrips and high temps.)

sooby said:If you're going to give them a shampoo best to do it early in the day before it gets hot because soapy things themselves can damage plants especially under hot dry conditions. Some people leave the soap solution on for a while and then rinse it off with plain water before the sun gets high. You could also try the shampoo in the evening when it is cooler and the soap effect will last longer.

Sue, I was just kidding
But if it's something beneficial I may try that!

The bigger mites you are likely to see running around with your naked eye probably aren't spider mites. The "bad mites" are very small, and best viewed with a loupe. I've heard that they might be predatory mites, a good thing to have around, but I'm not positive.

Unfortunately, mites are very hard to kill, and as a result, miticides are very powerful, and will generally kill everything, both good and bad, leading you down the path of total dependence on chemicals. Water, directed in a brisk spray at the underside of the leaves is probably the best thing you can do for the mites. Do it in the early morning, and don't worry about how damp the soil remains. Not having daylily rust gives you a lot more flexibility. If you need more "power", use soapy water, but keep in mind that it must be a real "soap", not a detergent soap, which may be harmful to the plants. Ivory Flakes and Dr. Bronner's are the only "real soaps" that I am aware of, so I usually buy a horticultural, insecticidal soap.

I really miss the time when I could indiscriminately spray and cool my daylilies on hot, dry days. I once set up some oscillating fan sprinklers to water my containerized daylilies when I went on a two-week vacation. I set them to run for 15 minutes, twice a day, around noon and three o'clock. When I returned, my plants looked better than they did before I left—lush, healthy and green. The sprinklers weren't delivering as much water to the soil as I normally did with my hose and water-breaker nozzle, but they kept the humidity high during the afternoons.

Ah, but we were talking earlier about dishwashing liquid sprays so I thought you might have meant that, Sabrina. I believe some people use baby shampoo in home-made remedies for plants also. I'm not generally a fan of using something not formulated specifically for plants because there is more risk of plant damage and also I suspect collecting together all the ingredients may work out more costly than just buying something like commercial insecticidal soap (which is also organic, where that's a concern, whereas concoctions made from household ingredients generally are not).

Ken, they use that technique on golf course greens during hot weather, as you may know. Called syringing. Just enough to wet and cool the turf leaf blades without watering the soil too much and causing problems when soil moisture may actually be adequate but cooling transpiration low because of high humidity. I think there's a move now to adding fans in very hot climates (for golf greens that is, haven't heard of anyone using that for daylilies).

I've used original Dawn dishwashing liquid for years with no harm to my daylilies. I've read that Ivory dishwashing liquid is used with equally good results. I live on the Louisiana gulf coast so heat is an issue 8-9 months out of the year. When I spray, it's early of a morning before the sun can create a prism effect on wet leaves. I feel if soap/detergents have to be washed off after being sprayed, too much was used in the first place.

I have never had spider mites (touch wood), but have done a lot of reading about them. Nasty critters.

UltraDawn dishwashing liquid is what was used in the daylily rust tests, although the study report covered themselves with a caveat about possible damage under some circumstances although they didn't see any. My comment about homemade was referring more to some of the concoctions that include multiple household items. The rust study used UltraDawn at 1%.

Ken, so I have two types of mites? Mites Kingdom here!
I will spray more often the plants with water to help them. I'm not keen to use something like dish soap or insecticidal soap just because we're in two different countries, I can't choose by brand and ingredients may not be the same. Sometimes I just can't find something similar to what you suggest.
Let's see what two days of rain and less heat will do.

Sue, sorry, I wasn't remembering we talked about soap so didn't think you could connect the things! My fault!

sooby said:Ken, they use that technique on golf course greens during hot weather, as you may know. Called syringing. Just enough to wet and cool the turf leaf blades without watering the soil too much and causing problems when soil moisture may actually be adequate but cooling transpiration low because of high humidity. I think there's a move now to adding fans in very hot climates (for golf greens that is, haven't heard of anyone using that for daylilies).

I wasn't aware of that—not being a golfer, I don't pay much attention. To be honest, the sum total of my fairway maintenance knowledge was gleaned from multiple viewings of Caddyshack. I do see that a lot of western golf courses are having problems and/or closing down due to the current drought.

cybersix said:Ken, so I have two types of mites? Mites Kingdom here!
I will spray more often the plants with water to help them. I'm not keen to use something like dish soap or insecticidal soap just because we're in two different countries, I can't choose by brand and ingredients may not be the same. Sometimes I just can't find something similar to what you suggest.
Let's see what two days of rain and less heat will do.

Probably more than two types. It may be a situation similar to fleas. There is a fun-factoid going around which states that the fleas on a dog or cat have fleas, and those fleas also have fleas. There are a lot of critters out there—the better your microscope, the more mites you're likely to find.

Rain or overhead watering will be little help—that's why the mites colonize the underside of the eaves. When you spray, concentrate on the underside of the leaves. A large volume of water isn't necessary—it's the force of the spray that really does the work—so use a fine nozzle spray setting that doesn't deluge the ground. Don't be afraid to get in there with your fingers and wash their protective web-netting off.

The brand names were for the benefit of the US members, however if you search out a good walk-in nursery or nursery supply in your area or even online, you should have no trouble finding an insecticidal soap product. One common brand here is "Safer's Insecticidal Soap", I'm sure there is a Euro equivalent. "Safer's" itself may even be available in Europe.

I have always used a 40 part water to 1 part dishwashing liquid as a spray for spider mites. I use Sunlight dishwashing liquid, the original lemon one. I just put that in a hand sprayer and spray the underside of the leaves. It is best to do it when it isn't too hot outside or if the plant is in full sun. I usually wait 15 to 20 minutes or so and rinse with clear water.

In our area, we have a call in radio show with a plant guru, Ed Lawrence, and whenever I think of the soap solution, I can hear his voice repeating the ratio of water and soap. He must have repeated that on air a million times

Math is not my strong suit but I think that's a lot stronger than the dilution of UltraDawn used in the daylily rust study. That latter was 1%, am I right in calculating that 1:40 is 2.5%? Could be a difference in the concentration of the detergent itself maybe.

sooby said:Math is not my strong suit but I think that's a lot stronger than the dilution of UltraDawn used in the daylily rust study. That latter was 1%, am I right in calculating that 1:40 is 2.5%? Could be a difference in the concentration of the detergent itself maybe.

It is not mine, either. I just went by Ed Lawrence's 'recipe' and have not had any problems. I rinse it off just to be on the safe side. I have used it on a lot of house plants and outdoor plants for various insects, such as spider mites, scale, mealy bugs, earwigs.