Growing Daylilies Together

I have read that some people trim their daylily seedlings while growing through the winter in the greenhouse. Trimming other types of seedlings results in a bushy lush plant so it might make sense for daylilies. But I have no evidence that it helps or hinders a daylily seedling. What do the experts think?

Trimming seedlings which then grow into bushy lush plants removes the growing tip from those seedlings. What that does is remove what is called 'apical dominance' and allows other buds to start to grow so the seedling develops many branches with leaves. Trimming daylilies only cuts the leaves - it does not remove the growing tip because that is hidden deep in the centre of each fan.

The seedling leaves make the food the seedling needs to grow so removing them reduces their ability to make food and to grow. However, removing some part of the leaves may not make a very large difference. How large an effect depends on how much is cut, how often it is cut, how the seedling is transplanted into the garden, how long the growing season is and probably many other factors. Some growers feel the effect is small or not noticeable; other growers with different conditions feel it is noticeable.

I had hoped that others would post what happens to their seedlings when they trim them so that you could form a consensus of opinion but that has not happened.

Unfortunately, as far as I know, there has been no published scientific research on how daylily seedlings are affected when their leaves are trimmed. There has been research on what happens when the leaves are trimmed in other plant species. We can try to use those results but it is not easy.

Plants do not have a choice about the conditions in which they grow. Wherever the seed ends up, sooner or later it either dies or germinates. Plants have evolved the ability to grow differently in different conditions and to be as fit as possible in different conditions - called phenotypic plasticity.

Theoretically, if one cuts some part of the leaves off the plant should suffer. Plants do not necessarily obey theory. When some plant species lose their leaves they act as if nothing has happened. They grow at the same rate as if the leaves were still there and at the end of a growing season will be smaller than if they had not lost parts of their leaves. Other plant species grow faster and they recover at least partially. Yet other plant species grow even faster and they recover completely so that at some time during the growing season they are the same as plants which had not lost part of their leaves.

We do not know what daylilies do in comparison to the other plant species that have been tested. And most of those species were tested as mixtures of immature and mature plants (or just mature plants) rather than only seedlings.

But it is even more complicated. In a plant species that recovers completely when it has lost leaves it takes time for it to do so. That means if we look at the plant at one time only it may not yet have recovered - so we need to look at the plant several times and those times may be over more than one growing season.

But it is even more complicated. For a plant to recover it needs to grow and that means that the conditions under which it is growing affect how fast it can grow. The obvious conditions are fertilizer, for example, how much nitrogen, how well the plants are watered, how strong the light is and how long the days are, etc.

But it is even more complicated. Some of the plant species that recover after losing part of their leaves do not recover if they lose larger parts of their leaves. Some do not recover if they lose their leaves later rather than earlier. That suggests that the length of the growing season affects whether a plant can recover in the first season after losing parts of its leaves.

When seedlings are grown indoors different people use different conditions. Also, their gardens have different length growing seasons and different temperatures, etc. The end result is that daylily seedlings that are trimmed by one grower may recover completely and quickly in their garden and growing conditions yet might not recover the first year for another grower in a different garden. It is difficult to make a prediction without knowing all the factors for each grower and with no research information for daylilies.

I would suggest that growers who would like to know the answer for their own indoor growing conditons, garden locations and garden growing conditions try a small test for themselves. For example, take five seedlings from one cross and not trim them and take another five seedlings from the same cross and trim them. Then watch and if necessary measure how they grow and see if the trimmed seedlings become as large as the uncut seedlings (or see how long it takes them to catch-up).

Hi Cathy,
I'm certainly not an expert but I do have some seedling trimming experience to share. I'm glad Maurice jumped in here with some scientific in put as well.
I've been starting about 1000-1500 seeds a year in my basement in January under regular florescent lights for 7 years now and plant them outdoors 4 months later. I have shelves made of 2 x 4 studs and 1/2" treated plywood (covered with heavy plastic). Each shelf holds 8 standard seed trays (some hold 10). The florescent lights are connected to the underside of each sheet of plywood. In order to accommodate the number of seedlings I grow on each shelf, I trim the foliage every few weeks to keep it at about 6" tall, enough to keep the foliage at least 4" from the light tubes. I have only one shelf (that holds about 200 seedlings) that has enough room that I do not have to trim the foliage of those seedlings at all. I water and fertilize with half strength Miracle Grow once a week.
Every year I have marked those trays of seedlings (that have untrimmed foliage) so that when I plant all my seedlings outdoors I can compare the root systems to the seedlings that had the foliage regularly trimmed for four months. The root systems on the trimmed foliage seedlings have always been much more plentiful and advanced than the untrimmed foliage seedlings. Now, it may very well be that the genetics of some of the specific crosses play a role in SOME of those seedlings, but I'm a firm believer, based on my own experience, that trimming the foliage was of some benefit to the more mature root development. The time it took for all the seedlings to bloom was still 2 years (here in zone 5 Ohio), whether it was the group that had their foliage trimmed or not.
I can also share that a couple of years ago, I helped a fellow hybridizer plant out in the ground his greenhouse grown (untrimmed foliage) seedlings that the seeds were planted in his greenhouses at the same time I planted mine in my basement. I was a little shocked at the puny root systems on his greenhouse grown seedlings and they had been regularly and heavily fertilized. I know many folks on here have strong opinions one way or the other about seedling trimming and I can only speak for myself and my own experience. It works for me!

Becki

Becki-Thanks for the reply. First hand experience was exactly what I what looking for. Your results are what I would have expected by judging what happens with other plants. My quandary was the whole idea of the leaves being the solar collectors for the roots. Though the blooming time is the same for you it seems as if the more robust seedling must have other benefits. Less transplant loss I would guess, though I do not seem to have much loss. I hold my seedlings longer in the greenhouse than you do. I begin them starting in August through october and keep them until outdoor planting time in April and May. Thanks for your input. Off I go to trim!!!!!
Thanks again!
Cathy

Cathy,

As Maurice explained, different plants react differently to their leaves being 'damaged' (whether through insect, chemical or weather-related damage or from a pair of scissors). When I am out and about my daylily beds, I'm always on the lookout for damaged leaves on my mature daylily plants and I carry a pair of clean scissors in my pocket. If just the ends of the leaves are damaged from whatever reason, I trim off the damaged part of the leaf at an angle just because it looks better. It never kills the leaf; the cut edge of the leaf just heals itself (when it comes to daylilies, a DAMAGED leaf is different than a dying leaf). Of course, I have a small enough property that I can do this. People that grow tens of thousands of daylilies obviously wouldn't want to bother. But sitting on less than a quarter of an acre with my house in the middle, all my daylily plants are up close and personal for my garden visitors and I try to keep them looking their best.

The young daylily seedlings I start from seed in my basement generally do the same thing when I trim them, they just continue to grow out. Occasionally, if it's a leaf on the outside of the fan, it may turn yellow and died down as newer leaves come out of the center of the fan. Keeping the foliage trimmed to no less than 6" still gives the plant the necessary foliage exposure for photosynthesis. For the 4 months these seedlings are in my basement, my main goal is not about their foliage development but rather their root development.
I have never lost a single seedling to transplant shock or anything else for that matter. The first few years I lost a couple of seedlings here and there due to damping off (while still growing indoors) which was caused by not enough vermiculite in my potting soil mix (Miracle Grow Potting mix). Once I started using a higher quality mix (Pro-Mix), I've not had that problem since.
Good luck with your seedlings!

Becki

Pruning WILL NOT improve the overall yield of a plant. This being the case, why do most gardeners feel that trimming their plants is important? There are many good reasons to trim the growth on a plant and when done properly, the desired effect will always be achieved. The main reasons to trim or prune indoor plants is to maximize energy distribution throughout the plant as well as to control the overall plant size and next is to improve the overall quality of flowers, fruit, foliage, and stems and lastly to improve and maintain plant health and vigor.

Pruning WILL NOT lead to an increase in plant yield. Pruning improperly can cause stress, serious damage to the plant, and an open wound through which disease and infection can infiltrate. These factors alone or combined, can drastically effect the growth and fruiting/flowering production on a plant. In extreme cases, improper pruning can even cause death.