Sweet sweet Goldilocks, you dirty little thief. If you were some kind of monster mobile mutant plant you’d be testing bowls of soil to see which you’d like to dip your dirty thieving roots into.
Some soils would be too clumpy. Some soils would be too loose. And some soils would be juuuuuuuust right. And that’s what we’re going for – Goldilocks Soil.
I love soil. If you want a quick and dirty [hah, pun!] overview of soil classification, click here.
Let’s look at the requirements of the plant – good aeration and drainage, and good water retention. So we need some combination of stuff that has this and doesn’t compact when we water it.
Unfortunately in container gardening, compaction becomes a huge issue, so we have to mix it up a bit.
So now we’re into all the different soil amendments and designer potting mixes and all that good stuff. This is getting fun. What different things can we mix and match to make good soil for our plants? I’m going to take a counter-intuitive leap here and say “Stop, don’t worry about it”. Really, don’t overcomplicate it, we’re farmers! We’re gonna use whatever is cheap, and close by or just right at hand. The plants will grow just fine as long as you remember the basic requirements – drainage to allow oxygen, some water retention to keep roots moist, and organic matter to help prevent compaction. And in that vein, I found some stuff around here that will do the trick, I hope.
My first ingredient is coco coir(coco peat). Coconuts grow in the tropics, who’d have thought. Coir is the fibrous husk part broken down into finer particles. It absorbs water like a sponge and doesn’t compact easily. Next ingredient – carbonized rice hull. Needless to say, rice is a faaaaaairly abundant crop here in the Philippines. “Carbonized” here just means “blackened using heat but not burnt all the way to ash”. CRH has great drainage, doesn’t compact much at all, and is an awesome medium for microbes. Next ingredient, soil. It’ll help with the structure but more importantly it’s free and close by(the gardeners in my apartment complex generously donated 2 sacks, sweet). Last ingredient, compost from Gil’s farm. This also was free and a much needed nitrogen/microbe source.
Of course you don’t want water sitting in the bottom of the pot, especially when your pots are made of flimsy 1/2in plywood. So I have gravel to layer the bottom for drainage.
Check out all the ingredients together:
I’ve mixed these ingredients up 2:2:1:1. 2 parts coco:2 parts CRH:1 part soil: 1 part compost. I think this is a good ratio – balance the drainage and water retention evenly, then compost for organic nutrient and soil for structure. Since coco, crh, and most of the compost are organic matter, overall it’s around 5:1 organic matter to soil. So in the end there isn’t much “soil” in my mix after all, hah. I hope this mix works out, just a little worried about drainage but we’ll see.
I’ve mixed the first batch of soil (on the tarp to avoid making too big a mess on the balcony). But before putting it in the planters, I have to line them with gravel. The gravel aids drainage which keeps roots healthy and will also help the planters last longer:
Not quite as much gravel fill as I would have liked, but I ran out. Oh well. Now to put the first batch in the planter…
…over an hour later, 3 planters are filled with soil. Now the plants are still weeks away from going in. They will be started in seed trays before being transplanted out here. The first thing I’ll do here is apply a compost tea to get the microbes started. I’ll talk about “The Best Compost Tea in the World” in a later post and article on the site.
Look at those beautiful planters inoculated with The Best Compost Tea Ever:
Last thing to do? Cover the planters with tarp. Keeps sunlight from reaching soil surface, keeps humidity up, soil moist. All to maximize growth of microbes in the beds. I’ll leave the tarp on for 5-7 days. In that time, fungi and bacteria will grow and thrive in the planters. The Carbonized Rice Hull, or biochar as we can call it, provides awesome habitat for these microbes. It is most effective when we have a good population going.
Can’t wait for planting!
Everyone who gardens has some opinion on “Goldilocks Soil”. I love hearing about all the different mixes people use – some are super extravagant and others dirt simple. If you have a soil recipe, please share it, and let us know why you make it that way.