I am not an expert, but I did grow about 24 trays of plant from seed last year with mostly great results. I tried Lobelia, Echinacea, Galardia and Petunias from your list. The Lobelia can certainly be in a shallower pot, their roots are not deep. Echinachea will probably not bloom the first year, but should come back gangbusters the second, so a smaller pot, even if it stunts them a little should be fine. Petunias have pretty extensive roots, so I would pot those up in the larger ones. I had mine in 9oz plastic cups last year (twice as tall as wide) and they did well. (as the petunias send out trailers, you can snip them and root in pearlite. I tripled my number of plants last year) Galardia (I grew dazzler mix) also did well in the 9 oz cups. They bloomed profusely by mid July. There arent many things that will do well in 2 1/2 inch pots for as long as you will need to keep them. Do check out the plastic cups at a dollar store, or Wallyworld. You can get a lot more height for the roots with out getting a lot wider (which is what takes up the light space).

I wonder if you could spread a 1/2 layer of perlite over the pea gravel -- would that keep the gravel from getting too hot? I know a lot of people are directed to the Plumeria 101 site, but I think those directions have to be adjusted for our individual, unique growing situations. I've had stem burn happen when it gets somewhere between 90 and 100 degrees. It might depend on how the cutting had been grown (sun vs. shade?). And, our summers can be so wet and humid that I never thoroughly water my pots when I first pot up the cutting (per Plum 101). I slightly 'pre-moisten' the mix and I believe this gives the cutting enough moisture to encourage rooting, but does not encourage rot. Then, like tdogdad, I create an indentation in the potting soil, which I partially fill with perlite, then place the cutting on that and fill around the cutting the rest of the way with perlite. Our ambient humidity will keep the soil moist for quite a long time. Only when we get really hot will I spray the cuttings and the top of the soil a bit.

ALL interior browning is normal ... no conifer holds its needles forever ... most 1 to 3 years ... as the canopy extends .. the interior are shaded out.. and turn brown ... its good to clean out this particular plant .. put on a leather glove... and just loosen and pull out some of that junk ... especially if you are in a high humidity area ... no need to be anal about it.. the more the better .. but no need to get the shop vac out there ... and do it every few years .. the more often.. the easier ... ken

"Where then are they getting the nutrients needed for growth? One can't dispute the need for nutrients in some form." Yes, in my comments above, I really hope I didn't make the impression that no nutrients were needed for plant growth. I don't always express myself well. I was trying (I may have failed lol) to make the point that - as you mentioned Dave - while organic nutrients in such mixes are not immediately available to plants, a percentage (usually a small percentage) of the nutrients are in available forms. Enough of the nutrients may be available to sustain the life, and modest growth, of the plant. Thus the claim of "no additional fertilizer is needed for two months" might technically be true. However, it's also true, as you point out, that purposeful applications of additional fertilizers might indeed help to promote growth, and make for healthier plants. I have found that experience is the best determining factor for fertilization. There are times when I cut back on adding fertilizers on purpose. If I do not want too much growth, too quickly, I won't fertilize... or I'll use less. I also usually wait until plants recover from transplant shock and become settled in new containers (sometimes more of an issue than other times... each case is different) before I fertilize. And, as we are discussing, the type of medium, and it's content of available nutrients, are a big determination of the need for additional fertilizers. I've become incredibly disappointed and have had problems with, the locally available products for transplanting seedlings, and my finances have me limited from investing in the better products which I would need to order. This year I have chosen to formulate my own from what I have produced right at home. So far it's working out better than I had hoped. It's simple, effective, organic, and has a basic level of available nutrients. I hope I can continue to produce it myself. It's free... with just a little effort.