Friday, May 1, 2015

Spring Update - Foliage Habit

Spring Update - Foliage Habit

In the early winter, I did this post on the foliage habits of daylilies in my garden and I published Di DeCaire's article on her experiences with foliage habit, so I wanted to do a follow up showing some of the same cultivars in the spring and discussing some thoughts on foliage habit.

I want to stress that I do not advocate any notion that all cultivars of any given foliage habit are 'good' or 'bad'. All daylilies have a place and all are right for some environment. The point of discussing foliage habit is that all daylilies don't work in all environments, but I personally believe that there are fewer that will fail in any given environment than will succeed. However, there are definitely some evergreen types that will either fail or perform poorly in cold climates and there are some dormants that will fail or do poorly in perpetually warm, southern climates. These are simple facts, and they are no attack on anyone.

With this disclaimer out of the way, I want to stress that one problem I keep seeing from every side and corner in the foliage habit discussion is the tendency to generalize. I see people say that all dormants are hardy, or that all evergreens are tender. Some say that all dormants are frost resistant, while all evergreens are frost susceptible. However, none of these things are true. I can't stress this enough. There are no possible blanket statements that can include 'always' or 'never' when we are discussing foliage type. It is a common human tendency to generalize, but it almost always misses the mark, because almost nothing in life is black or white. Life is shades of gray and this is also true of foliage habit. 

So I want to dismantle these generalizations and encourage people to look at the nuances we see in each and every cultivar. Finally, it is important to remember that all cultivars are not necessarily accurately registered for foliage habit, while some cultivars perform differently than they are registered for foliage type in environments different from the one they were grown and registered in. This often isn't any attempt at deception, it is just the nature of the beast. Daylilies can be highly variable depending on the environment and can perform very differently for foliage type when moved around the continent.

'All dormants are hardy and all evergreens are tender.' FALSE! There are tender dormants and very hardy evergreens. However, both of those examples are in the minority, but they do exist. The tender dormants are probably the rarest of the two things, and there are a good number of evergreens that are perfectly hardy. However, all evergreens are not hardy. The only way to know which dormants are tender or which evergreens are hardy is to either grow them and see what happens or to talk to people who have grown any cultivar you are considering in an environment similar to yours. And I must stress again - similar to yours. If you are in zone six or seven, there are evergreens that will do better further north or further south than they will for you, because the heavy snow cover throughout the winter in more northern areas insulates the plants from the extreme cold and drives them into a state not unlike dormancy. Yet in the more temperate yet still cold zones there is little to no snow cover for much of the winter, thus plants are exposed to drying, desiccating winds, extreme variations of temperatures including warm spells followed by cold spells and these can be exceptionally destructive to plants that might otherwise perform much better in both warmer and colder areas. So be sure you talk to people in a climate similar to yours to determine how a given cultivar might work for you. Your other option is to simply try the plant and accept the possibility of loss or poor performance.

'All dormants are frost resistant, while all evergreens are frost susceptible.' FALSE! Both statements are generalizations and not true. In my garden, I see a wide range of frost resistance/susceptibility and it isn't dependent on foliage type. I have registered cultivars and seedling that are evergreens, which show frost tolerance and I have registered cultivars and seedlings that are dormant, which are frost susceptible. There is no apparent linkage between foliage type and frost tolerance levels. It is so important to remember that each cultivar must be judged individually on not just on the registered foliage type. 

So with that out of the way, let's look at a few of the cultivars I showed pictures of in my blog post from 12/23/2014. This first group of pictures were taken on March 22, 2015.

Here we see Bill Fall on 03/22/2015. This hard dormant shows beautiful, frost tolerant foliage emerged from the resting buds of typical hard dormants.

I showed these three cultivars in the previous post last December. The one to the far left is a registered evergreen, though it actually goes nearly full dormant in my garden and arises from what appear to be resting buds. It also shows high frost tolerance. The cultivar in the upper center is a registered semi-evergreen and behaves much as I would expect, showing some frost damage and keeping foliate above ground all winter. The cultivar to the far right is a registered dormant, but it is the most frost susceptible of these three cultivars and it does not go underground in winter, nor does it  arise from resting buds in the spring. You can see it shows the most damage from winter cold of the three.

Here we see Challenger, a registered evergreen that performs as a dormant in my climate, rising from resting buds in late March of this year. It also shows strong frost tolerance. I have both this tetraploid conversion and the diploid version of this cultivar, and both perform in the same manner.

Here is Priscilla's Rainbow, another registered evergreen that goes dormant in my garden. Here you see it arising from its resting buds. This cultivar though does not have strong frost tolerance, being moderate in that regard.

Here is the semi-evergreen cultivar Gleber's Top Cream. You can see the winter damage in this picture from 03/22/2014. This cultivar recovers well, but it shows poor frost tolerance.

Here is a clump of an evergreen cultivar showing the result of cold winter weather. This cultivar recovers well and is quite hardy, but this is what it looks like after cold weather. While this is not a tender evergreen, it is a true evergreen. In my breeding program, it throws dormant seedlings as well as evergreen seedlings. It is a useful plant, but it is not a pretty sight at this time of year. When you compare this plant to the other registered evergreen cultivars that I have shown in this post, you can see that they are not the same type of foliage, regardless of the registration. The plant in this picture does not rise from beautiful resting buds and the foliage takes a time to look nice again.

Here we see Monica Marie, a registered evergreen that goes dormant in my garden. Here we see it rising from resting buds, showing beautiful foliage. This photo was taken the same day as the photo above of the true evergreen. These photos were taken the same day 03/22/2015. When you compare the two pictures, you can see a strong difference between the two plants.

This next group of pictures are from 04/02/2015, nearly two weeks after the previous pictures and the day after a hard frost.

This picture shows three cultivars in a row from right to left. On the far right is Bill Fall, a hard dormant with great frost tolerance. In the center is Insider Trading, a registered evergreen that tends toward dormancy for me and has good frost tolerance, recovering in just a day or two from frost damage. The third plant on the far left is Karen Stephens, a registered semi-evergreen that shows only moderate frost tolerance, but that recovers well.

Here is a registered dormant cultivar with poor frost tolerance showing considerable frost damage. This one does not tend to recover well.

Here is another registered dormant cultivar. It shows poor frost tolerance, even less than the one in the previous picture, but it recovers more quickly.

So I hope these pictures show that there is considerable variation in daylily foliage habit and frost tolerance. There is no way to generalize. Each cultivar has to be taken individually, and on top of that, each one may vary widely in any given garden depending on many variables such as soil type and composition, micro-climate and climate zone. I think foliage habit is an important discussion, but I also think it is important not to generalize so that we can have a discussion about actual observed facts, remembering that our observations in one garden may not be the same as what is observed in another garden with different climate and conditions.