i really think you'll like it. Try and get medium or coarse vermiculite instead of fine.

Okay. Thanks again.

@abhege, I have a question about using straight vermiculite.

I have often mixed vermiculite and or pearlite into my seed starting mix (which is very fine), but have noticed that it seems to me a good place for algae to begin forming. Have you had that problem?. It is especially a concern for really slow germinating and slow growing seed that don't get transplanted for a while (for example Begonias and Lisianthus).

It maybe that I can simply see the algae more clearly on vermiculite, but its an issue I haven't figured out how to deal with easily.

I never use vermiculite so don't know about the algae issue. I have never seen algae on my perlite though. The only time I use perlite (and it is coarse) is when rooting Plumeria cuttings. I have left those cuttings in the perlite for six weeks and even longer, with no algae. Perhaps if you use tap water to moisten the vermiculite before sowing your seeds (water that has been chlorinated [city-water]), that bit of chorine would prevent algae. This is just a guess though.

I am using vermiculite for seed germination.
It is just for germination, and does not contain any nutrients, so
you need to be ready to transplant sprouts to a soil mix.
Or else add dilute fertilizer to keep the sprouts growing.
I find less algae and molds etc. with vermiculite and less damp off too.
It is easier, and cleaner, to use when the kitchen or bathroom becomes the potting shed!
It is especially good for germinating alpines, and other plants which like really good drainage.

Caroline, I am certainly no expert here, but the reason I quit using vermiculite years ago was because it RETAINS too much moisture and retains it for a longer period of time when compared to perlite. You are correct in that neither product has any nutritional value. I would think that when something needed to be used for growing, say, cacti, perlite would be a far better additive than vermiculite simply because a perlite mix is far better draining and less water-retentive. That's been my experience.

I germinate my vegetable and herb seeds in either milled sphagnum or peat.

But doesn't the straight peat compress down so that when you water it only hits the surface. Unless you are watering from beneath in trays. I need to go back and read the instructions about planting in vermiculite to see how nutrients are added. Could add it through the watering using hydroponic fertilizer I guess.

Mary, you can moisten practically any substrate you want by either top-watering (though you might have to use more of a mister/sprayer and do it several times over several minutes to saturate the "soil") or bottom-watering. Perhaps peat will compress over a long period of time (certainly, the peat I buy is in compressed bales), but when germinating seeds, the peat just won't be used long enough to compress to any extent. Again, this is just my experience. Any water-soluble fertilizer can be used but there is no need to use fertilizer until you have quite a bit of plant growth, say when the "true" leaves form.

Speaking of peat, if I had to choose one medium to germinate seeds and my choices were peat moss or milled sphagnum, I would choose sphagnum simply because it does remain fluffy, doesn't hold water quite as long, and has a neutral pH. Peat is more acid.

Oh boy. Now I am torn. Vermiculite, perlite, sphagnum, peat moss? I am talking germinating just plain old garden variety (no pun intended) vegies and flowers. No exotics or tempermental plants. I am also fascinated by pictures I have seen of planting in the drainage trays used on the edges of houses to catch rain. People plant in those in short lengths then simply push the soil into the garden in nice neat rows. I would think lining with plastic wrap would facilitate the 'sliding' motion.

I have never had an algea problem sowing i vermiculite. Remember, the main purpose is to get the seeds to germinate. You should pot them up when the develop first true leaves. They do not need fertilizer before that point.

That said, I had some seedlings that did not get potted up for over 2 months. As long as the tops don't bump the lid you can just leave them. They won't really develop until they are potted up.

Ken, if you read the instructions you will see the vermiculite is moistened, not saturated.

I think you should use what works for you but maybe try the vermiculite method as a trial for a few seeds to see if it might be for you. It definetly is cleaner and easier.

I think I will do so. It sounds too good not to try. I may start some early ones just to test and if that works out then follow up with the main planting. And I will keep re-reading the instructions as my memory keeps leaving out steps.

Keep in mind that I grow mostly epiphytes and moisture retention is not what I am after. Vermiculite is certainly fine for germinating seeds but since I no longer use vermiculite for my potting "soils", I simply use what I have. Milled sphagnum works just as well, at least for me, and is very "clean" to use. I buy 10 cf of it a year.

There is a fine line between moist and wet. I can't always stay on one side or the other of that line. Sorry, I am just an ordinary hobbyist and probably not all that skilled..........

No, it's just that you have a different need Ken.

Hmmm……My algae issues must come from the environment. I haven't done a serious scrub down in my grow room for a while. I pretty much never have damp off, and rarely have trouble getting my seed to turn into healthy plants, even with the occasional algae growth. This year I plan on bottom watering the seedlings that are slow growers (which I have never bothered to do) and I will top the mix with chicken grit, which should make for a non-hospitible surface for the algae.

Will stuff grow through the grit? Or only certain stuff? How's my technical jargon ..

I would be just about as technical, Mary. I have never owned a chicken. Let's have Geof answer that.

I have never owned a chicken either, but I used to have two cockatiels. Chicken grit is basically just very very fine gravel. Though with the small quantity I would need I would probably just pick up what ever they sell in the pet section for birds, as opposed to buying a 50lb bag from the farm store here. Larger seedlings could easily push right through it. I am less sure of the tiny ones. It might need to be added after germination for some of them.

I'll have to experiment.

Survivors. Last weeks polar blast reached 12 degrees F and hung around in the upper teens low tewneties for several days. Some plants survived with flying colors others not so well. Collards were no surprise as they are exceptionaly winter hardy.
Nor di I expect much damage to the rutabagas . Was not sure about the cabbage, but Greenbriar came through fine. Cauliflower and broccoli were harvested before the cold snap, but I am surprised at survival of sprouts on the Emerald Giant.
Expected damage to greens and got it. Roots of turnips and winter radishes are fine tho.
Willet Wonders are always survivors
Biggest surprise. I have never had onions suffer freeze damage before. It was fairly extensive of both Desert Sunrise and Miss Megan. I expect them to survive but I also expect a lot of bolting.

Lots of things looked really good. Sorry about those that didn't make it.

Lots of cold spells here this winter but we have had milder wi9nter where those cabbage family crops survived all winter. And of course those root veggies like the rutabagas did well. Too cold this year though.