Potting mix less the peat

Hi, I'm new here. I figured I'd just jump right in and start asking questions.

I'm getting ready to start potting up this years seeds and wanted to know if any of you have a recipe or know of one for a peatless mix. I've seen one in a book I read recently, but would like to hear what others may be using and what their experiences have been.

Thank you

Welcome Ally!

Well - I use ProMix as a base and mix in starter grit for the seeds that need really good drainage.
I've tried all sorts of brands & mixed my own but I've fallen in love with the texture of ProMix.

After having issues with fungus gnats, I've found running a fan over the seed pots really helps.

Tam

Thanks for the reply and welcome Tammy.

I looked up ProMix on the web and noticed that their mixes all have peat as the base. I would like to try a mix this year that doesn't have peat or composted bark since they tend to be rather acidic and react with the high alkalinity of the water here. I'm still trying to understand the actual chemistry behind this. Sadly I've never taken any chemistry and I tend to mix up what PH acididty and basicity(?) is as well as how the alkalkinity affects said substrates. Throw into the mix what fertilizers you use and I get even more confused.(Sigh) So anybody want to throw in their two cents? Meanwhile I'll keep at it.

If I hadn't had issues with seedlings quickly dying off last year as soon as I started watering with city water I wouldn't have given this a second thought. I'm still very new to growing things from seed. However when I started using collected rain water to irrigate the affected seedling most pulled out of the funk they were in. Well, that is the ones that didn't die. Just for the record I found that Draba and Dianthus seemed to be particularly sensitive.

I'll have to rummage through the books on my side table to find the one that mentioned a peatless mix. Seems like I remember something about using equal parts perlite, vermiculite and sand/grit.

Hi, Ally --

I never use vermiculite in anything, but I can't quite remember the exact reason. I read somewhere that it should be avoided because it doesn't help with drainage or aeration or something else that seems essential, so I avoid it.

The mix I use when I want to avoid peat is equal parts of grit, aquarium sand, perlite, and potting soil, but it's the potting soil that's sold specifically for cactus. It's a nice lean mix that's suitable for lots of different plants. It's utterly useless for others, of course, such as Primulas.

In case you haven't discovered Mt. Tahoma's Web site, here's a link to it. There are some interesting and informative pages on this site, especially if you're interested in growing alpines or growing plants in containers.

http://www.backyardgardener.com/mttahoma/index.html

Incidentally, I agree with your description of Draba as sensitive. In fact, I've found that Draba is the most temperamental and vulnerable plant I've ever tried to grow.

I've got spring water supplying me (just a mechanical filter, a UV light and a deacidifier for purification)
so I haven't the issues with water supply. I've used Coir instead of peat, but mostly for convenience. Its
made from coconut hulls. (I'm not sure if its less acid).

I wonder if its regional issues with draba. I've done better with them from seed than many other types of
alpines. And so far so good in the garden.

Welcome Ally!

The city water problem might be due to chlorine. It use to be that all chlorinated water supplies were done with a volatile chlorine compound that "aired out" when water is left exposed to air for a while. Now most(I think) municipalities are changing over to a chlorine that does not "evaporate", and we're out of luck. Seedlings, of course, are always more vulnerable to nearly everything. Therein might lie the problem, and hopefully it would be only temporary.

As for your soil chemistry "inneptitude":

Neutral pH=7.0
Low pH=acid=sour
High pH=alkaline or basic=sweet
pH is a logarithymic scale: pH 4 is 10 times more acid then pH 5, which is 10 times more acid than pH6 . . . and it works the other way on the alkaline side: pH9=10 more basic than pH8 . . .

Yes, sphagnum peat (the fibrous stuff) is very acid, as are most barks used, but a little less so. Reactions between them and alkaline water is a good thing for most alpine plants as the high pH of the water tends to moderate the acidity of these mediums over time. Still, for alpines they are not good components to use in high quantities without further adaption.

Regular compost(not composted bark) is only slightly acid(maybe pH6.8) and is a good buffering medium, helping to keep soils from getting too acid or too alkaline. Most cactus mixes are sand with compost. Compost is often used in alpine mixes.

The vermiculite problem elude to is probably that some can contain small amounts of asbestos. As I understand, horticultural vermiculite no longer can include asbestos by law. I could be mistaken here though. But if the source of the vermiculite is from areas west of the Dakota states, asbestos is not a component. From the Dakotas and east, it might be.

The aeration quality of vermiculite does break down in time, but like perlite, it DOES improve aeration. The difference is that vermiculite can hold water within the particles too, while perlite can only retain miniscule (but effective) amounts on the outside of the particles. Perlite also contains traces of flourine, that only causes problems if a particular plant is very susceptible. I know of no alpines in this category. Perlite is great to use in a mix for alpines, but vermiculite would be best for primula.

I also general use promix as a base for my mixes, alpine and otherwise. It has a surfactant(wetting agent) that makes handling mixes with it in it more amenable. But maybe only about 5-10% for alpines.

Rick

Hey there Rick, good to see you posting here. I've been going over that link I posted back on GW about the affect of water alkalinity vs. substrate PH again. I think the basics are starting to stick. I hate feeling so 'inept' in regards to these things so I'm trying to do something about it. I'm actually learning about this in a basic biology class I'm taking right now.

Thanks for the link Zuzu. This is a great site with some lovely plants. I checked out the page on growing alpines and found it to be quite helpful. I'm going to try a variety of mixes this year and see how it goes.

I'm not sure about the Draba Tammy. I've read that it is an easier plant to grow but they sure don't seem to like me. I did manage to keep one little D. oligisperma alive and planted it out. I'm hoping it makes it through the winter in the open garden.

Thanks again,

Allyson

Here's a trio of draba sp I grew from seed last year. I took it today. They seem quite happy.
I didn't take a picture of it but my draba bryoides rigida is doing well in my trough.
I've sure killed a lot of other types of rock garden plants but draba's do seem
easier than most to me.

That is a lovely site this time of year. I still can't see any green in my yard. The snow is melting quickly but my little rock garden is still nothing more than a collection of lumps and bumps under a blanket of snow.

Those look similar to the Draba I bought from Beaver Creek this fall. I've got a few more varieties that I'm going to try from seed. Hopefully I'm more successful this year.

I hate to think about how many plants I've killed. I've only been rock gardening for about 3 years now. I'd like to think that at sometime in the future I'll reach a stage that I'll know enough not to kill any more plants. But I'm afraid I'll won't live that long.

Ally- thank you. This garden is covered so no rain or snow gets on it during the winter.
I'm not very experienced rock gardening either. I've had a trough for about 12 years but
just started a real rock garden a couple of years ago. I just love the cute little dainties!

Are you going to the NARGS International conference this summer? Its in Utah. I've
been looking at the agenda off & on for a while. I'd have to go my myself but it sure looks
really wonderful! (I'm a whimp about travelling on my own. But I might just steel my nerves
and go anyway if I don't use up my vacation planting & working on my own place during
the spring).

Tam

I doubt it. I was hoping that I could pay to attend just the lectures and presentations I wanted to go to. I've not seen that this is an option. I don't have the time or money to go to all of them. Which really bums me out, because there were a couple that I would really like to attend.

I am seriously thinking about going to the Interim Conference in Utah. At least a couple of Minnesota members are going for sure.