Really don't have much experience with containers. I've read some gardening books that say never add garden soil to a container -- too many pests and diseases and also can cause rot. Then I've read equally reputable books that state that you must add some garden soil, because potting soil isn't "heavy" enough and won't hold enough moisture.
Which is true?
Basic soil question from a container newbie
You should never use garden soil in a container, it's really more about the drainage than it is about pests and diseases although those can be a concern too. Potting mix is made especially to work in containers, it will hold some water but still allow good drainage, and you should absolutely not add garden soil to it. If you're growing thirsty plants or are in a hot climate, there are water absorbing polymers that you can add to your potting mix which supposedly allow you to go longer between waterings (Miracle Gro Moisture Control potting mix comes with some of these already mixed in). I am curious which reputable books are advising you to add garden soil to the container mix? I have never seen that recommended anywhere and can't imagine a truly reputable book doing so.
SandyRN - read tapla's sticky. It explains about container soils and the need for good drainage, etc. I know it is long but it is excellent. Even if you don't use his potting mix recipe you will learn a lot of container gardening!! Eleanor
Thanks for the info. I'll definitely read the sticky.
ecrane, I've read this sort of advice probably in 3 or 4 different books, mostly library books over the past 2 years, so I don't recall those titles, but one from my own Better Homes and Gardens New Complete Guide to Gardening (1997). It states that if you use a soilless mix, you must add one part good, loamy, crumbly garden soil or commercial potting soil. It reasons that this will buffer against changes in nutrient levels and pH. It then goes on to give the following "recipe":
1 part good loamy garden soil or commercial topsoil
1 part organic matter (peat moss, leaf mold, compost)
1 part sand, perlite, or vermiculite
1/4 part bonemeal or rock phosphate (for phosphorus)
1/4 part greensand, granite dust, or langbeinite (for potassium)
Would you use such a mix? Do you think it would cause drainage problems? Thanks!
I would never put garden soil or commercial topsoil in a container. For a raised bed it might be fine but for containers you need to stick with soilless mix. I'd read tapla's thread, there are some good container mix recipes in there if you want to make your own. I'm lazy so I buy the premixed potting soils, probably not quite as good as making your own but I don't have time to do my own.
I too buy container mix and I have about forty large cedar pots and nineteen earthboxes.
I mainly use "Jungle Growth" in my cedar pots and earthboxes or EBS as we call them. I have also used Miracle-Gro, Sta-Green, etc. As long as they are a quality mix and the label or back of the bag does not have the words "soil" or "not for containers" as the organic mix does manufactured by Miracle-Gro, I have been more than happy. Down here the cost for a 2 cu ft bag is about $7.00 or so, so it does get expensive if you are on a tight budget but I am partially disabled so not much choice.
These are older pictures but you get the idea. I have half size and 1/4 size cedar barrels.
Plus my nineteen EBs. The potting mix lasts for years. All I do is add to it. Eventually earthworms start to grow in them and this is a good thing.
Thanks for everyone's input. Much appreciated.
Here's my soil recipe:
1 cu. ft. peat moss
.5 cu.ft. composted manure
8 qt bag perlite
9 oz limestone
6 dry oz 15-30-15 fertilizer
I mix the peat moss and lime together really well. I then add everything else and mix thoroughly again.
I have more pots than I dare count and numerous 4' planter boxes and it works like a champ for me. (It rewets easily, too!)
Donna