Over the years I have tried various mixes and have made up some of my own as well. I find that many commercial mixes just don't give me the results I want and some seem to be actually inhibiting growth . I've had good results with Schultz of late and terrible results with stuff from Canadian Superstore. I can't seem to find Scott's around here but it was pretty good as I remember. Jiffy mix didn't cut it for me either. I should tell you that I am starting petunia, pansy, bacote lobelia etc all very tiny and delicate seeds. Tomatoes just thrive in Shultz where I lost at least 50 seeds out of 51 to the superstore product and the loner is still at the dicotyledon stage after 5 weeks. So what do you use ? Bob
We just mix peat and perlite for our seed starting: vegetables and annuals. Gardening guru Thomas Hobbs swears by Dutch Treat potting mix. On Saturday's show, he did add perlite to the potting soil: http://canwest.a.mms.mavenapps.net/.../current/launch.html?maven_playerId=gardening
Thanks Debbie: That's pretty much the way I have been doing it here but as I mentioned the seeding mixes from some places are questionable. I found the one from Superstore to be quite coarse and very difficult to wet. Once wet it seemed almost too wet if that makes any sense. The seeds that germinatied went directly into "lurch" mode in that material. ??? I've replanted everything in Schults mix and seem to have about 95% germination. Bob
That sounds familiar! My normal compost atm is just the garden chain store's (Homebase's) basic 'houseplant' mix, I find it's okay for a plant that needs moist soil all the time but for something you have to let dry out a few inches, when you come to water it all the dry soil floats to the top and i have to wait ages for it to soak through. Must be a case of poor wetting agents (my compost claims it has them) and bad drainage....probably not the best 'qualities' in compost. I'll try getting some John Innes next time see how that compares. I don't have masses of experience with growing seeds but my swiss cheese plant seed seemed to like the compost I have as it germinated in half the time expected, yet my cacti seeds haven't geminated at all (that I can see) even when i mixed in half sand. I also sowed 10 Coleus seeds, 6 have germinated but one is wilting, so probably won't last long!
I've settled on the Premier Pro-Mix PGX starting mix, which is a superfine peat/vermiculite/perlite blend. There is a wetting agent, nutrients, and some lime to bring the pH to about neutral. I buy it in compressed 3 cu. litre bales from the local ag/farm supply place. This is an awful lot of mix for a single gardener, unless you've got a greenhouse or a friend to split the order with. The PGX is the finest-screened mix in the Premier product line. Since the tray surface can be levelled to a really smooth, flat sowing surface, the PGX is great for seeds that are surface-sowed and need light to germinate-- tiny seeds don't get lost in crevices, and the entire surface can be kept uniformly moist. Also, if you need a super-fine "dusting" of mix to just cover fine seeds, take some of the mix, dry it out, put it through a fine seive (a kitchen wire sieve will do) to remove all but the smallest of the peat fines. What remains will have an almost powder-like consistency that you can sprinkle by pinches, or use the sieve to put a fine dusting over your tray. If you want something less expensive or you're doing larger seeds, you could try the Premier Pro-Mix BX which is the general purpose version. The Premier Hort web site has a ton of product details. You may have trouble finding any of the professional Pro-Mix products in the city, since it's used by greenhouses and farmers. When I lived in the city I could sometimes find a greenhouse/garden center that used it in their own growing/potting operations (so few of them start their own annuals from seed any more). You can ask the staff if they'd part with a small bag, for a few bucks. I've tried regular potting mixes (Schultz, Scotts) and even the "premium" mixes are still pretty coarse with rocks and twigs. The less expensive stuff sometimes has shreds of black plastic from the bags that didn't get pulled from the compost windrow. I wouldn't use this coarse stuff to start small seeds in. But you can cut costs for larger seeds by using the coarser mix in the bottom half of the cell or large plug, and putting the fine grade mix on top. A word of caution on compressed potting mix: don't let it freeze over the winter while compressed. It permanently loses its loft and it doesn't hold moisture as well.
Bev, are you saying "seeding mix" or "potting mix" ? I'm having problems with Seeding mixes and looking for an all round solution if possible. I have been using sunshine mix for potting up and it seems to be alright here for the amount of heat/light I get in the greenhouse in March- May. I have a feeling the house brands are too acidic as they appear to be just peat. Bob
The stuff they sell at the garden centers looks to be marketed as "all purpose"-- for seeding and potting. I guess they figure we'll buy anything once. All retail bagged mixes, even the top grade ones, are too coarse (for seed starting) for my liking. The Premier Pro-Mix PGX I described is a specialty mix for seeding. The BX "general purpose" mix can be used for seeding as well, but I found it too coarse for all but the large seeds. I know that the local garden center uses the BX for their vegetable starts and a lot of the seed-started annuals, but I think that's because they don't want to bother with different grades of mix-- they just want to buy one thing that works with all seeds, whether in trays or plugs or cells. Of course, they have optimal conditions-- water, warmth, humidity-- and using a general-purpose seeding mix probably doesn't make much of a difference. If you only want to buy one product and you have the time to do it, you could use bagged potting mix and put it through a sieve to remove the chunks, and use it for seed starting. You wouldn't get the benefits of the wetting agent or the peat, but at least you'd have something a bit finer for seed germination. When my seedlings need to be potted up I use a home-made mixes with the following ingredients in various proportions, depending on the plant's needs: - leftover PGX seeding mix from last year (lost it's loft and no good for seed starting) - bagged commercial compost (up to about 1/4 by volume) - perlite or sharp sand - vermiculite - garden soil, but only if the seedlings are big and robust and are ready for the cold frame-- I never use home-made compost or garden soil on stuff that comes indoors None of this is very precise-- I just mix stuff in small batches with a scoop and get something that looks and feels about right. I just googled "Sunshine Mix". This seems to be an "out west" product line-- we don't see it here in the east. It's nice to see they're doing an OMRI organic mix. None of the Premier products are certified for organic growers.
I thinks you have a good handle on what the short commings of hobby seeding are. We simply dont have the proper time frame and the proper mixtures to allow us to be away all day and still maintian adequate moisture and decent matrix for the smaller seeds. Sunshine Mix is a great product . It has a decent matrix and sufficient perlite to keep it fluffly yet allows good moisiture retention. I have been working in a layer in my gardens every year for about 5 years and the results are beginning to show now. Bob
