CaliFlowers said:

Sue P. - is the seed-starter layer underneath the cells also coir-based?

No, the layer under the cells is either Jiffy mix seed-starter or Espoma Organic seed starter. I bought both but didn't keep track of which flats got which seed-starter.

CaliFlowers said:
Regarding trimming, it seems to me that you're at the point where maximum growth is no longer a priority. With leaves reaching past your light fixtures, and the rest crowding the lamps and shading the other leaves, a light, uniform trim might be beneficial, as it would allow more light to reach the other leaves. As the plants develop, their spacing should increase, but that's not really practical, and there's a limit to how high most of the lights can be raised. The trimmed plants will respond with more leaves, and there's a possibility that fewer of the outer leaves will brown if the total leaf area of each plant is reduced a bit. Ideally, an indoor seedling operation would be designed so that half of the lighted bench area could be held in reserve so that as the seedlings grow they could be spread apart for better growth. Usually that's not practical, so we make concessions.

I think I'll do a test and trim just a bit off of one flat and see how things progress. I love testing techniques.

CaliFlowers said:
I still have a few flats of seedlings under lamps, in 3.5" pots, with up to 10 plants per pot. I've been taking them outside during the day to get sunlight, but I bring them in at dusk so that they can get a few more hours of indoor light in the evenings, along with a little more warmth than they get outside. The lights also come on before dawn in the morning. They really respond to the rain. My favorite crosses have been bumped up to 6" square pots and are growing outside. I usually move the contents of one 3.5" pot to a 6" square pot or a 1-gallon nursery container, loosening the roots a little to space the seedlings a little further apart. They seem to not notice the disturbance, and are good until they go into the ground.

The following doesn't apply to your situation because the roots of your plants are growing together in the under-flat of seed-starter medium, and will need to be teased apart—which is a good thing.

When transplanting any single cell-grown plant to a garden bed, it's true that they will not suffer transplant shock, but I don't recommend transplanting this way. If a container-grown root ball is just plunked into the ground, initial watering must be directed specifically so that it wets that root ball. If the bed is uniformly overhead-watered, the root ball can dry out fairly fast while the native soil surrounding it remains wet. The plant probably won't die, but it'll struggle until roots grow out into the surrounding soil. In the case of daylilies, their foliage helps direct rain and overhead watering to the base of the fans..

I have some flats that were planted ONE seed per cup (they are small cups). They didn't seem to do as well as other flats that were growing in "company" situations. About two weeks ago I lifted them out of their cup, cut the bottom off of the cup and replaced them into the same cup, then they were put back into the flat with a bottom layer of seed-starter like the other flats. The roots were already circling around the bottom of the cup so I think it was a great improvement for them.

ALL ! ! I know I'll be back to ask more questions when it gets closer to planting them in the ground. I love ATP and its members.

Great idea to do a test, do please let us know your results. I know of a couple of other people who've tried this and the cut back seedlings were slower to gain size - and remember that the ability to flower depends on the size of the fan, so slower growth of the crown means later flowering. Sometimes, though, you gotta do what you gotta do.

In theory at least, cutting the leaves back from the tips is a double whammy. Firstly your're reducing the area of leaf that can photosynthesize and produce food for growth. This means that the new growth for a while may need to take its energy food for growth from what is stored in the crown, and/or grow more slowly on what is available from current photosynthesis.

The second whammy is that the most developed cells for photosynthesis in a monocot seedling leaf are the leaf tips because they're the oldest part of the leaf. So any extra light that falls on the remaining parts of the leaves may not be used as well as it would have been on the tips.

Sometimes theories don't pan out because of some unforseen factor, so do go ahead and experiment because the result will be useful information for yourself and the rest of us either way.

petruske said:
I have some flats that were planted ONE seed per cup (they are small cups). They didn't seem to do as well as other flats that were growing in "company" situations. About two weeks ago I lifted them out of their cup, cut the bottom off of the cup and replaced them into the same cup, then they were put back into the flat with a bottom layer of seed-starter like the other flats. The roots were already circling around the bottom of the cup so I think it was a great improvement for them.

I've noticed this as well. Gang-planted seedlings tend to do much better - particularly when they're very small, and I suspect it's because there are more roots in the pot, which probably tends to mitigate any excess moisture problems. Sometime around the middle of November I planted a round of seeds in 3.5" pots, and have had them under lights, outside on nice days, and in the rain whenever possible. When I was sowing, I had room for one last pot under the lights, and the envelope had almost 30 seeds in it, so I put them all in that pot. They've done surprisingly well, and today the plants seem to be at least 80% the size of those in the other pots, which ranged from 4-10 seeds at planting time. The crowded pot is drying out pretty quickly now, and I have started dunking it in a weak fertilizer mix to keep it going. It needs to be dealt with soon, because the sides of the pot are starting to bulge noticeably. I like that these will self-select for vigor and stamina, and once I tease them apart it'll be easy to pick the toughest 10 or so to grow on.

It's a wide-format picture, so you'll have to click on it to see the whole thing.

This is a flat of seedlings, mostly from Steve Todd's (Ahead) Lily Auction offerings. They're from his tet Rose F. Kennedy lines crossed onto various parents, including some of Judy Davisson's best. Most of them were beginning to sprout in the refrigerator in mid-March. I used a greenhouse-grade potting mix for the lower 2/3 of the 3½" pots, topped with a coconut coir/perlite mixture. Because they were very nice crosses, and I didn't want the neighborhood cats, raccoons, crows or anything else bothering them, I built tray-top cages out of ½" hardware cloth. These are a little more elaborate than usual—I typically lay a flat sheet of ½" hardware cloth over the tray—but with the taller cage I get a little more growing time in before I have to ditch the cover. They're showing pretty good growth for three weeks. A couple of the pots contain crosses from other sellers and which hadn't sprouted in the fridge. They were a little slow to show, but every day I see new shoots. Pretty close to 100% germination now.

so much for sharing your experience and pics of your seedlings. They are very helpful to newcomer like me. I appreciate it all very much.