Hostas like neutral to mildly acidic, so no on the gypsum. I don't know on the lime...

If you are potting them this Fall, I would not add the ferts. Next Spring you can water with dissolved miracle grow or what ever. Then, when the weather warms to a constant 80+ degrees add slow release ferts to the surface (lightly scratched in) for the Summer.

Garden lime will raise the ph so you don't add that either.

I just use 2 main ingredients (and ferts when applicable): pine bark and perlite. imo, the sphagnum peat and other stuff retains too much water making the mix too soggy.

hth,
Deb

No, I wasn't planning on adding the fertilizer until spring.

Question though:

is there any benefit of adding some vermiculite? Thanks for the feedback.

By the way, Deb, what ratio do you use?

I just mixed up a batch to temporarily pot some hosta. I used 50% pine bark mulch (broken up into quarter - half dollar sized chunks) and 50% sphagnum peat moss. To ten gallons of the mix, I added one cup of 10-10-10 and a cup to a cup and a half of grated up sheetrock (gypsum). Used a cheese grater and elbow grease/ doesn't take long to grate up a couple of cups of it. Didn't have any lime on hand and it was easier to grate up the sheetrock than traipse to the store and haul home a heavy bag of lime.

I decided to add the gypsum because peatmoss has a ph of 4.5-5 and pine bark is very acidic/ 3.5-4.5 (although probably next to inert in the mix?). Ideal ph for hostas is supposed to be 6-6.5. And, my soil is acidic as well...these hostas will eventually be planted out in the garden.

Next time, I think I'll use more bark and less peat moss. Pine bark mulch was the only pine bark product that I've been able to find. That's why I ended up having to break it down myself. About 10-15% of the bag had pieces too big to break up by hand. I ended up with more than enough from one bag to do the job. (DH had just put a new blade on the lawnmower so resisted the urge to use it to break up the chunks.)

I don't add peat, either ... just pine park mulch, perlite, and composted cow manure. For every 2 cu.ft. bag of mulch, I add one-third to one-half bag of c.c.m. and about four quarts of perlite or vermiculite. If the mulch if course, I add a little more c.c.m. and little less perlite, and if it's fine then less c.c.m. and more perlite. The perlite helps with drainage. I keep all but one of my nearly 200 hostas in side-draining pots and have had good luck with this mix.

funnthsun,
For my potting mix I use what's sold as soil conditioner (for the pine bark & compost part) and perlite. The pine bark soil conditioner has "fines" in it that hold enough moisture as it is and i don't want any more.

No percentages to my mix, I just go by "the look" of it.
If I had to guess it'd be: one 40lb bag of soil conditioner and one (or a little more) 8qt bag of perlite. Keep in mind that's a guess-timation.

Please use caution that you don't breathe in the perlite dust while dumping it in and stirring it up.

There isn't a lot of science to my method and sometimes folks won't agree with that way of thinking and that's OK. I'd recommend using what you have/can find and see how it works for you.

Vermiculite holds moisture, so keep that in mind if you use it. I tried it in the past but didn't like the texture/wetness, so I don't add it anymore. Just my preference.

The main idea is for your mix to drain well.

I cut little squares of window screen wire and place it over the drain holes in the bottom of the pot. Some folks will place rocks the bottom of the pot, but that hasn't worked very well for me.

My pots sit on bricks (or whatever) so they aren't sitting directly on the ground and can more freely drain. Some of the members here use neat looking "pot feet" that can dress up the pot for a patio setting.

hth,
Deb

Thanks for all the feedback. I did go with pine bark mulch, peat and perlite (even though I've always hated the look of perlite--dirt should look like dirt!--sigh Yeah, I know it's not dirt.) It's best for the hostas, so it will be fine with me.

I didn't have to break up my pine bark mulch, it was pretty fine already. Discarded a handleful of big chunks and that was it.

Cilantro, the reasoning behind your adding the gypsum makes perfect sense to me. I may consider that the next time I mix up a batch. Now, to upload some pics of my newly potted little guys...

My Pappy once told me if you want to see the smart way to do something, watch a lazy man do it.

If you don't like the look of perlite in your mix, add pine needles on top as a mulch to camouflage it. Be sure you don't bury the hosta crown too deeply, though.

Deb

Yep, that's sort of what I have planned. I'm going to add a sprinkling of the pine bark mulch over the top. That should do just fine.