Gardeners Have Stopped Buying Potting Mix: What They Use Instead Is Already in the Yard
Potting mix disappears fast once large containers, fruit bushes and perennial plants need filling. Instead of opening another bag, gardeners can start with something already under their feet. Soil taken from the yard can make up most of a container mix when combined with compost or another source of organic matter.
Ben from GrowVeg demonstrates the method with a mix built around garden soil. Starting ratio is seven parts soil to three parts organic matter, with adjustments based on how well the soil drains. For gardeners with homemade compost, most of the mix may already be sitting outside.
Start with soil from different parts of the yard
Rather than digging out one section of the garden, collect small amounts of soil from several spots. Avoid areas covered in weeds, along with soil containing perennial weeds that could end up growing in the container.
Molehills can provide useful material too. Soil pushed up by moles has already been broken apart, leaving the loose, crumbly texture shown in the video.
Soil provides weight and structure, which matters for trees, shrubs and other plants that may remain in the same container for years. Organic matter supplies the other part of the mix.
Mix seven parts soil with three parts organic matter
Start with seven parts garden soil and three parts organic matter. Garden compost is used in the video, though leaf mold or well-rotted manure can fill the same role.
“Parts” don’t require a measuring cup. Use a bucket, plant pot or scoop and keep the measure consistent. Seven scoops of soil and three scoops of compost create the same ratio as seven buckets and three buckets.
Mix until the compost is distributed through the soil.
Change the ratio if your soil holds too much water
Heavy clay soil needs more drainage. Ben drops the soil from seven parts to six and replaces that part with grit, creating a mix of six parts soil, three parts organic matter and one part grit.
Sandy soil needs the opposite adjustment. Since it drains fast, the extra part goes to organic matter instead, producing six parts soil and four parts compost, leaf mold or manure.
The three versions come down to the soil you start with:
- Average soil: 7 parts soil + 3 parts organic matter
- Heavy clay soil: 6 parts soil + 3 parts organic matter + 1 part grit
- Sandy soil: 6 parts soil + 4 parts organic matter
The price difference comes from what you don’t have to buy
He compares the homemade mix with a 40-liter bag costing £8, or about $10. That works out to around 20 pence or 25 cents per liter.
Garden soil costs nothing to collect, and homemade compost adds no new purchase. For the clay-soil version demonstrated in the video, grit is the only ingredient counted toward the cost. The finished mix comes to about 7 pence or 9 cents per liter.
If the soil doesn’t need grit and the organic matter comes from the garden, the mix can be made without buying an ingredient.
Don’t use the same mix for starting seeds
Weight is one reason this mix works for larger, longer-lived container plants, but it also makes it different from seed-starting mix.
Ben recommends this soil-based version for plants such as trees, shrubs, fruit bushes and perennial flowers. Seedlings need a lighter mix with a finer structure, so soil dug from the yard isn’t being presented as a replacement for every bag of growing medium.
For established container plants, however, the biggest ingredient may be sitting in the yard instead of on a garden-center shelf.
Would you make a container mix with soil from your yard, or keep buying it by the bag?