Soil is the best medium in which plants grow. Ideally, the soil should be well aerated, retain moisture, with nutrients to feed plants, and encourage microbial activity.
The soil should contain 60 percent topsoil, 30 percent compost, 10 percent potting soil, worm castings, azomite, mycorrhizal fungi, and fish emulsion water.
If you can’t find fish emulsion, then use a nitrogen fertilizer in the correct measurements.
Drainage & Lining
All planter boxes and raised garden beds require adequate drainage for the plants to thrive. Without it, the plants will remain in soggy soil, causing root rot and eventual plant death. Since planter boxes have solid materials all around, it is necessary to drill several drainage holes.
For elevated, you can drill up to six holes at the bottom. If the planter box sits on the ground, several holes on the sides close to the bottom will do the trick.
On the other hand, raised garden beds are already sitting on the ground. It requires you to lay a lining of old newspapers or cardboard materials on the floor before filling the soil.
You should avoid using plastic materials that compromise the soil’s drainage ability.