How long will they remain in the media you choose?

Al

Probably 4-6 weeks?(for hippeastrum) At least until large enough to transplant. I have traditionally used a seed starter which contains peat and some vermiculite. But the mix does dry out quickly and if kept moist attracts fungus gnats, which are not good near seedlings. I guess I have found your soil discussions to be very educational and wondered if you had some unique ideas on seed starters. Other seedlings would be the traditional spring starts, coleus,petunias,tomatoes, but I guess those grow fast and it maybe doesn't matter so much...

Well, initially, all that's of much importance is aeration and moisture in the media, but soon after the true leaves form, you need to be thinking of nutrients, and that can be a problem.

If you stray from a sterile, prepared mix (say, Jiffy seed-starting mix, e.g., which is mostly peat & vermiculite with lime) that hasn't been pH adjusted with liming materials, you'll likely end up with nutritional deficiencies of Ca/Mg, because they're absent in many fertilizers.

I don't start many seeds, but when I do, I usually begin with either pure perlite, Turface, or a mix of both. I suppose coarse sand, of 1/2 BB size to BB size would work, but since Turface has great internal porosity and perlite/Turface both, have greater surface porosity, they'll both be superior to coarse sand and will be more convenient because they hold water better w/o becoming saturated.

Preferred: I first screen out the fines from the Turface by screening through insect screen. I then mix in crushed limestone (adds Ca & Mg) with the coarse Turface and scatter the seeds on top of the coarse material. Finally, I cover them with the fines from the screening process. The depth of the covering depends on the seed size, but it's generally from 1/8 - 1/4". I mist when the top of the media shows dry, until seeds germinate. At the first true leaves, I begin irrigating with an appropriate fertilizer blend mixed into the water, usually 12-4-8 with the minors, at 1/4 recommended strength.

Alternately: I would use perlite in place of the coarse Turface & follow the same procedure, including covering the seeds with Turface fines or sand.

I know I said I start seeds as noted above, but really, I do something a little differently. I don't use the limestone, because it can raise pH more than I prefer (7+, and I usually like something I'd guess to be in the 5.5 - 6.5 range), so instead of limestone, I use gypsum (adds Ca). If you do this, you'll need to supplement your fertilizer program with Epsom salts because the Mg (supplied in limestone) will likely be missing from the fertilizer you use - check first.

Did that all make sense to you? answer your question(s)?

Al

It does make sense. I have a "soil perfector" by espoma (a ceramic material that I'm thinking might be like turface?) The bag is HEAVY. Is it a concern as to how heavy the medium is when dealing with small roots on a new seedling? Or is it incorrect to assume a seedling would have fragile roots and might have an easier time in a more flexible medium like the traditional starting mixes? Also, if I may ask one more question, how would your previous discussions on the aeration of container soils apply to seedlings considering their need for moisture and the smaller size of their containers- is it the same but on a smaller scale or should I treat them differently? Al, I really appreciate your advice, I have learned so much reading your posts.(although there is always so much more to learn and understand!)Thanks!

Thanks for the nice compliment. ;o)

I believe Espoma's Soil Perfector is made by the Haydite Hydraulic Brick Press Company, and while they DO make several products that will work for seed starting and in soils, I've found the Soil Perfector to be a little too large to suit me. It will make a VERY fast soil if used in any substantial volume in container soils.

Weight is no consideration when only growth is the subject. It may be a consideration in windy situations or for other concerns unrelated to growth, though. Seedlings' roots are very fragile, yes. They do break easily, but they will grow just fine in a bucket of jagged glass, if you supply water and nutrients, so hardness of the media parts is no consideration as long as (again) it contains air, nutrients, and water (and is not toxic to plants). Wind and rough treatment can be a problem, though.

Seeds/seedlings do extremely well in highly aerated soils, as long as you maintain adequate moisture. Those two physical conditions are key. Since the seed contains all the nutrients the seedling needs to get started, even nutrition initially takes a back seat to air/moisture.

I just started some Coleus cuttings about a week ago in coarse perlite. As soon as they struck, and within about 3 days, I could see the roots just about shoot all through the perlite (clear plastic container). I would have no trouble growing them in the perlite or in 100% Turface indefinately, as long as I pay attention to moisture/nutrient needs.

Al

Thanks for asking that salpal. Once again I learned another trick from Al. I'm glad I saved one bag of turface for this and other uses. filix