No places ready to plant yet, so I want to pot up all my new dwarfs and medians and a few small TBs to give them extra growing time.

I have seen that Miracle-Gro and fine bark recipe that Neal posted recently (probably too expensive for my pile) and I have known some to plant in what looks like pure compost Just found Arlyn’s interesting post including potting instructions. I also have the recipe from a grower of daylilies who sells in pots. It has 6 ingredients, peat, perlite, sand, soil, compost or soil pep and osmacote! What do the rest of you potters use? I think I would prefer a mixture including some garden soil. Some soiless mixes break down and don’t want to have to pack soil in under the rhizomes in the future.

I use about 2/3 potting soil mixed with 1/3 perlite. If I use all potting soil the rhizomes don't seem to thrive as well.

I guess it depends on how long you intend to keep them potted up. I only pot them for a short time if at all, and I get buy with a mix of potting soil and garden soil. I don't know what would work for over wintering them. I don't do that.

I use 1/2 potting soil, and 1/2 garden soil for my potted Iris. I only pot iris to assist them in root growth, and/or when I receive iris rhizomes that are to small to be planted directly in the garden and need pampering a little. I started potting some of my Iris rhizomes in July. They will be transplanted into the gardens in September.

Not sure how valid what I use will be for you given the different zones, but I throw a lot of my Iris into pots, sometimes temporarily and sometimes left over winter. I generally use a mix of about 1/4 potting mix or garden soil to 3/4 Hapi Gro Landscapers Mix:

I generally use the "heft test" when buying potting mix......and potting "mix' IS different than potting "soil"......When you are shopping in your "nursery", or home store, grab onto a bag of "topsoil" and pick it up. It's pretty heavy ! That's because it contains a lot of "mineral soil"....sand, silt, etc. Then, find a bag of shredded sphagnum moss, and lift it....it's very light, because it's all a low density ,all -organic product. What you want, is some thing about half way between those, in weight. The 'all organic" WILL work...it's very loose, holds moisture well (and still drains excess water fairly well), allows for easy "root growth", and ,of course, doesn't pack down, and become a "brick" in the pot. And the " topsoil" will work, as well.....that's what they are going to grow in, when you finally "plant them out", after all......but in "pot culture", it's going to be too 'stiff ' for water penetration, and easy root growth, and require much more attention as to watering........when and how much.....to keep the iris happy. As to any "added' fertilizers.......some potting mixes have it, and some don't....I don't think they are terribly important.....you can add a little of your own fertilizer (sparingly !) or water with a dilute Miracle Grow solution, every 3rd, or 4th time you water. Perlite is added to lots of potting mixes in order to keep it lighter in texture, and reduce 'packing down'. But , if the mix has enough sphagnum moss, or shredded bark....they do the same thing
I usually buy my"mix at a local Manard's ....it's their own "brand', and a big sack is about $11 (I think ? I really don't remember...so it must not be TOO expensive ), and when I get "out and about", I'll read the "ingedients", and post them. I often reuse it, after finally planting the iris, to pot up the next batch....and, sometimes I "plant" the entire contents of the pot, when I plant the iris....if the dirt I'm planting in needs more 'organic content, or just leans to the "stiff" side.....it can stand the amendment of some" loose" stuff.
Bottom line, IMHO, is it's not rocket science....and, in most cases...it's only a temporary thing, as you will be planting them out, after a month, or two, so , really almost any commercial potting mix will do fine (as will any "home made" mix that approximates a commercial blend), so, depending on how many you have to deal with, $10-$15 worth of mix will go a long way, and , as I mentioned, can either be reused, or incorporated into your beds as an amendment.

All the bagged stuff my old housemate brought home was full of bugs that infested my houseplants. I am still battling fungus gnats in the house. There are horrific accounts of Miracle-Gro disasters online, from pests to mold to weird shredded plastic to petrochemicals in product sourced from China. I got some Miracle-Gro AV and succulent mixes from Lowe's. I can get away with them if I freeze to kill active bugs and then bake to kill eggs and then mix a teaspoon or two of Actinovate to keep away mold.

I think peat moss mixed with garden soil and some pelletized flowering plant food would be better than chancing the above.

Sounds like you have covered all bases, Linnea. I do not have the time or patience to freeze, bake and treat a planting medium. I get mine from Good Earth soil company. It is about 30 miles away but I take the old garden truck and get a large amount at once. They have a very neat operation there. I have to drive around to the back to get loaded and they have very tall mountains of sawdust, sand, soil, tree bark and compost. they have huge house sized bins of compost working. They make their own mix in a huge machine and the soil goes up a large incline like a roller coaster and gets more finely ground at the end and then falls into large metal bins. you can buy it by the truck load or by the bag. Since I am affiliated with a garden club and the Good Earth sells at our annual spring plant sale they know me and I get a real good deal. That way I can use the mix for me and for potting plants for the spring sale also. I never opt for the fertilized mix as I like to control what type of food my plants get. Just before Christmas each year he has a sale for all bags not sold during the season for two dollars each. I shop for dirt at Christmas time. A gardener never really has a down time just time we cannot be outdoors.

The stuff I use is "Master Garden " potting mix, and lists components as: Canadian Sphagnum moss(15-20% by volume), peat humus, perlite , limestone , slow release fertilizer. The 'fertilizer value' is; 1.25%--0.21%--0.30%

Good Earth sounds like a dream come true!

I use potting soil from local nurseries, not big box stores. I've used different brands with about the same amount of success. If I'd known how many bags I was going to go through this year, I would have gotten a yard (or two) of potting mix from the landscape supply place. Many of the local wholesalers get their soil that way, and you can customize it and add or subtract the amount of ingredients.

Thanks everyone,

I have some bags of planting mix from several years ago, so I'll check their ingredients and see how they compare and mix 50 percent with soil. I'm only planning the iris to be potted for two months or less, so will skip the fertilizer.

Could someone share the post by Neal on Miracle-Gro and fine bark recipe

I've been using either "planting mix" or "potting mix" (mostly the former) mixed 50/50 with fine redwood bark. I highly recommend saucers under the pots during warm/dry weather. No need for added sand/perlite/vermiculite (maybe a different story if you are potting in clay or heavy soil).

I found this post from Neal about Miracle-Gro but I don't know if it is the one Charlotte is referring to:
https://garden.org/thread/repl...

Good detective work, Robin.

I don't have the luxury of putting my irises in the ground at my current house, so they're all in pots for the next few years. I modified the recipe on the Scrheiners website and they have been very happy. They said 45% fir bark, 20% pumice, and 35% peat moss. I had trouble finding the pine bark, so I picked a nice mulch, subbed the perlite for the pumice. Plus a little bone meal when I plant.

I'm having a hard time wrapping my head around using peat moss. Any kind of fine bark and anything else well draining, I guess.

I pretty much use the same potting mixture for both irises and daylilies, unless I am in a hurry, in which case plants go into whatever "recycled" dirt from pots I am no longer using. Judging by the results in my raised daylily seedling beds (originally filled with fresh 10% vermiculite and the rest 50/50 planting mix and fine bark), the bark breaks down fairly quickly (within 2 years), adding organic material to the mix. Generally at the 2 year mark I need to dig and beef up the beds again, so it's back to the original mixture to replace any lost soil volume.