You can grow a whole garden without having any real in-ground soil.
The results can be fabulous. And the options are endless when you can start a garden on a street corner, a back yard, a deck, some paving, a bit of asphalt or gravel, or a terrace.
Plants need water, and often container gardening needs a little more focus on that. But more than anything they need good soil. And the so-called soil you buy at the garden shop just doesn’t do the work it needs to do.
Garden shop soil, or potting mix, is often based on a form of compost. In worst case (and nearly all Swedish ”soil” falls into this category), it’s based on harvested peat that really should have been left in the ground.
While these type of substrates often work well for a season, or half a season, they tend to compact and become dry and hard to water after a while.
The nutrients that they were pumped with (usually in chemical form although occasionally they use animal manure) are depleted. They never had any micr- life in them. And as a result, plants struggle.
The solution is to renovate these soil substrates by mixing them with bokashi. You can do this before or after a growing season; the important thing is never to throw away soil because it has become useless.
It can always be fixed up! And should be.
One of the easiest ways to fix this soil is to tip it all out of its sacks, bags and planting containers at the end of the season. Or prior to the beginning of the next.
You can mix it with bokashi in a wheelbarrow or on a tarp and fill your containers from there. Or you can layer the tired soil and bokashi directly into the containers, buckets, planters you’ll be using for the next season.
One third bokashi and two-thirds soil is a good rule of thumb. A little stronger, up to 50 per cent, if you are going to plant intensely or plant bigger, or more demanding plants.
Making bokashi soil in a planter
A good method is to put a bottom layer of drainage material into your planter; gravel, stones, broken ceramics, leca balls if you have them in your country. Then a layer of soil; it makes no difference how poor it is.
Then your layer of bokashi, straight from the bucket where it’s been fermenting. Another layer of poor soil. And finally a nice, attractive layer of fresh dark soil that will look good on the surface.
You may wish to prepare a whole bunch of these containers ahead of time, ready for the coming season or for when your seedlings are ready to go out.
In this case, it’s no problem if it’s cold and the bokashi will take time to turn to soil. You can line them up along a terrace or in the greenhouse and when the time comes to plant they will be ready there waiting for you.
Or you may just want to prepare one or two tubs or planters ready for your summer flowers.
Use the same method, but wait a couple of weeks before putting in any plants with roots that will reach into the fresh bokashi. The reason for this is that newly fermented bokashi has a very low pH, it’s quite acidic, and needs a couple of weeks to stabilize with a normal pH that your plants will like.
On the other hand, if your plants are small and your container is big, you can probably plant directly.
If you think it will take a couple of weeks for their roots to reach down into the bokashi zone there is no risk. The process can sort itself out during the time your small plants are growing. And when their roots do reach the bokashi supply they will get a pleasant surprise, and no doubt start growing fabulously!
This method is good if your plants are all similar, and their roots are all going to end up at about the same depth.
Sometimes, though, when you do a summer planting of different types of flowers, they will all need different things at different times.
What I do then is mix the soil and the bokashi in the wheelbarrow. The same mix: one-third bokashi, two-thirds soil, but just more homogenous. Then I fill the planter and top it off with some ”nice” soil.
In this case you really need to wait before planting the container though, as the roots will get in contact with the bokashi immediately if you were to plant them straight away. Wait two weeks, and then even if you can still see traces of bokashi, it’s ok to plant your flowers.
Another thing with container gardens of this type is that they will probably attract worms. Sometimes it’s impossible to understand where they come from; in the harshest of urban environments they can just turn up sometimes. And next thing you know there’s a worm colony in your container garden.
It’s just to be happy; worms are wonderful. And as long as they’re happy they will stay.