To be completely honest, I don’t buy much garden soil. I mix my own. There is a difference between raised bed soil and potting soil.
Potting soil holds more moisture than raised bed soil, and usually has more fluff to it. Raised bed soil often contains heavier and cheaper ingredients. It also should have larger chunks to improve drainage. Raised bed soil usually contains more compost and sand than potting soil, and is slightly cheaper.
So, there’s a clear difference between the two, but what difference does that actually make? Can you swap them without actually having a problem?
How Raised Bed Soil is Designed
Raised bed soil is a mid-weight soil product designed with a high amount of organic content, usually municipal compost or composed manure. A lot of them seem to have a base consisting of even amounts of compost and sand, then some additives. Additives include mulch products, peat moss, and coco choir.
It’s expecged to last a long while without needing any added by the gardener. Most raised bed soils have a bit of chunky mulch (woodchips and/or tree bark chips) mixed in. Basically because it’s cheap and it may help improve drainage. Drainage is a big, often overrated deal for raised bed soil. But, it is important.
Raised bed soil usually have quite good drainage, more so than average garden soil. That’s just in case you put a raised bed ontop of poorly drained soil so it doesn’t become a swamp. raised bed soil soil considered halfway between potting soil and garden soil.
Less drainage and more compost than bagged potting soil, more drainage and less compost than garden soil. BUt, that’s just a generalization. In reality, experts all have different mixes they prefer. And yes, potting soil will work in a raised bed, it’s just more expensive.
If you took potting soil and added more sand and compostr, it’d be raised bed soil. That’s all the difference between the two.
How Potting Soil is Designed
Potting soil is made with the main concern of drainage because the most often cause of bad plant health in pots is overwatring. Potting soil is usually very high in fluff, like peat moss, and has a lot of puffed sand. it is usually lower in compost and regular sand to make it lighter so pots aren’t too heavy.
There are two products, vermiculite and perlite. Perlite made from a fine, glassy or sand like material that is superheated so that the particles become fluffed. It has large but lightweight particles which improve drainage and aration without myuch added weight.
Vermiculite is litle balls of folded, fluffed clay mterial that takes up water to improve the lasting water-holding cpacity of a soil product. it also improves drainage of standing water because it’s a bigger particle.
The tiny hair roots of plants can get inside these puffed sand paeticles and extract the water. that’s how potting soil can hold some water for plants, but never become swampy no mater how much it’s watered. If you took raised bed soil and added more fluffy stuff, and some puffed sand, it’d be potting soil
Using Raised Bed Soil in Pots
You can use raised bed soil in pots. It does increase the risk of flooding plants if you have a habbit of overeatering. It works best in larger pots, 1/2 gallon or bigger. If you are observent, raised bed soil will work alright as a potting soil. It’s not such a different product.
This year I built a raised bed off the end of my greenhouse. I filled it with a mix of composted manure, chopped hay, leaves, and my native soil. I used the same mixture to fill 100 1/2 gallon pots and a few 2-gallon pots for tomatoes. The tomatoes grew well. The 1/2 gallon pots were for my spring plant sale.
The 2-gallon pots are sitting next to my driveway with happy, mature tomato plants in them. For both pots and raised beds, the big concern is not making a swamp. Just whatever soil you use will not remain waterlogged and swampy for long after being watered. Beyond that, make it fertile and black.
Using Potting Soil in Raised Beds
Potting spoil can be used to fill raised beds, but it’s often more expensive. Potting soil may need added compost to make a decent raised bed soil. It’s not ideal because it has almost too much drainage and will likely need extrafrequent watering, but as it breaks down, it will improve.
If yuo use poting soil in a raised bed, work to build a natural topsoil layer. use something like grass clippings or leaves as a mulch. They break down quickly and will improve the qiality of the soil, making a more natural soil product.
Most raised beds are filled with a lot more organic matter, mainly compost, than any native soil. Coming from my background, soil with over 10 percent organic matter was supposed to pose concerns of nutrient lock-up, phosphorus toxicity, and loss of fertilizer. In gardening, appherently 50 percent is fine.
I know people who use mostly pure compost and it does seem to work. I suppose the bigger issue is just learning to work with whichever you end up doing. I will say that unless there’s something added, pure compost is more likely to get waterlogged, so bear that in mind.
Mixing Your Own Potting Soil
Light-weight potting soil- equal parts by volume peat moss (well fluffed), perlite, and vermiculite.
Medium-weight potting soil– mix quality compost and peat moss 50/50 by volume and add an additional 10 percent perlite, vermiculite, or sand. This mix won;t be too heavy and will be well-drained.
Heavy potting soil- Mix equal parts (by volume) peat moss and soil. If soil is mostly clay, add sand to give it a more gritty texture to improve drainage.
Mixing Your Own Raised Bed Soil
Basic Raised Bed Soil– By volume, mix 50/50 of sand and compost. Some prefer a mix of 1 part sand,1 part compost, 1 part peat moss. I like a mix of my native soil and compost. If your native soil has decent drainage, then you can use it in a raised bed.
If your soil is mostly heavy clay, you can substitute your soil with purchased topsoil. Raised beds can be filled with pure topsoil with good results, as long as the topsol is good quality.
Can I Just Use Dirt in Flower Pots or Raised Beds?
Good quality garden soil is alright for raised beds. Making it fancy with added ingredients can help if you live in a area that’s prone to a very wet season. If you do use regular soil, be sure to add a good amount of organic matter to it every year so it doesn’t become depleted. It should be nice and black.
Related articles:
