Hi everyone!
I checked my DLs and I saw that two of them have these little holes on leaves, even the newest one. It seems only two of them are affected. Do you know what can cause this?

My guess would be a slug or snail. I just put out slug bait last week because I had seen some while weeding one of the seedling beds.

Sabrina, that is very similar to one of the symptoms of "spring sickness", those holes are possibly caused by bulb mites when the leaves are very small. Check out images 4 and 5 on this page:

http://web.ncf.ca/ah748/spring...

Fred, I already put slug poison all around, so I don't think it's cause of slugs.

Sue, so the lettuce leaves were really spring sickness. This is happening on the same two plants that had lettuce leaves. I have to read if it's there a sort of treatment?

If by lettuce leaves you mean a frozen look, no that's not spring sickness. With spring sickness the fans are stunted and/or bend sideways and have "saw-tooth" ragged edges and holes in the leaves like in your pics - I don't remember now, did I think some of your previous pictures looked a bit like spring sickness?

No, no treatment that has been proven because we don't know for sure what causes it. Bulb mites may be involved but the damage occurred most likely before the leaves even appeared above the soil. We don't know whether bulb mites cause some, all or none of the damage for sure but the damage is typical of what they do to other plants, and they've consistently been apprehended at the scene of the crime in spring sickness. I've seen similar damage on tulips in the presence of bulb mites too.

Most of the time the plants will recover on their own and can still flower. In some cases there may be what I presume to be a secondary infection and the fan can rot but looking at yours I don't think that will happen in this case. You could try giving them some liquid fertilizer, that may help them grow out of it. Some people cut off the affected fans but that's just to remove the ugliness.

Edit: I would also say that if those leaves were frozen at some time those holes could be some kind of physiological damage from freezing causing uneven growth in those areas. We know full scale spring sickness isn't caused by freezing after fans emerge but there could be more than one cause of certain symptoms. It's also possible that a daylily might get frozen and already have been going to get spring sickness, doesn't necessarily mean they are related.

I remember you mentioned spring sickness maybe because of the "ribbon like" leaves I had.

I cut those fans (I left 10 cm from the ground) and they are slowly growing, but the new leaves show that holes too. When I cut the leaves I felt with my hand that they were really "hard", I don't know how to explain it. Like a sort of thin wood.
One of these DLs emitted a new fan that is completely healty, deeper green, no signs on leaves.

Some leaf has that saw tooth ragged edge, yes, really near to the ground, and a rust color.
These two DLs never disappeared during the winter.

I just fertilized them with a liquid fertilizer, soil was very dry I didn't give much water so it's not really humid. I was expecting rains but no rain came until now.

New leaves didn't get freezin temps I guess, near 0°C.

Yes, the fans that are affected by spring sickness may be a different colour. I think "brittle" may be the word you were looking for? If it is spring sickness I do not think there would be a connection with not having disappeared in winter. Daylilies die back every winter here and still get spring sickness when they emerge. I actually see it more in those that are registered "dormant".

The two plants with suspect spring sickness are light green, except for the new fan one of them is producing.
Brittle and dry, yes, as something that's not really "alive". One is an EV and the other is a SEV, both behaved in the same manner this winter, but I wasn't take it as a connection. I will wait and see what happens!

Sure sounds/looks like Spring Sickness to me. I often have that on many of my daylilies. I wish there were some conclusive knowledge and a way to avoid Spring Sickness. Last year my daylilies looked SO good in the early spring. Then we had several frosty nights and the Spring Sickness began. They always grow out of it, but it sure makes them look awful for a while.

Sabrina, once you're familiar with spring sickness, you can often tell which fans are going to do it even before they do because of the different colour. Sue, the frosty nights appear to be coincidence because if you dig up a daylily that was planning on getting spring sickness before it emerges above the ground and bring it indoors, it will still get spring sickness in the warmth of the house. Also in some years there is no frost after growth starts outside and they still get spring sickness. So it starts even before the fans emerge in spring, it just takes a while for the affected plant parts to grow into view. In many gardens spring sickness can be predicted to make an appearance around the time forsythia blooms.

One member of the unofficial "spring sickness task force" had some reduction in spring sickness with the use of insecticide and fungicide (separately). It may be caused by a combination of factors, the prime suspects currently being bulb mites in cahoots with the leaf streak fungus (Aureobasidium microstictum), but there may be other factors as well, such as soil conditions. I've sometimes wondered if soil pH was another contributing factor but so few people actually know their soil pH it hasn't been possible to do a meaningful survey on that.

Thanks again. I will let the fans as they are and see what happens.
What it looks strange to me is that it appears on one fan and not the other, on one plant and not on another.

cybersix said:Thanks again. I will let the fans as they are and see what happens.
What it looks strange to me is that it appears on one fan and not the other, on one plant and not on another.

That's typical of spring sickness and one of the things that makes it hard to figure out.