Nutrients — Soil

Feeds for growing in potting soil. The choice matters less here than on other media, because the soil does part of the work itself. What matters more is when you start, and at what strength.

Start later than you think

A bag of pre-fertilised potting soil holds enough feed for the first weeks. Feed on top of that straight away and you are running high before the plant needs anything, which shows up as clawing leaves and burnt tips. In practice: water only until the plant asks for more, usually somewhere in week two or three, and build up from there. On a light mix or a depleted reused batch you start sooner. What each soil contains is set out under Potting Soil.

The complete terra lines

CANNA Terra Vega and Terra Flores are the best known, with the Terra Starterskit as a way in. Plagron pairs Terra Grow with Terra Bloom, also sold as the Easy Pack and Top Grow Box. Hy-pro supplies Terra with a matching Epic Bloom and Rootstimulator Terra, plus the Smart box discovery pack for trying the line first. Atami has B'cuzz Soil Nutrition A+B with the Soil Booster Universal beside it, and the Ata line with Terra Max and Terra Leaves.

One bottle, or powder

If you would rather not run two bottles, Bio G Power Aarde 1 Component covers the whole cycle. Atami offers Premium Plant Powder Soil for mixing yourself; powder weighs less and keeps longer, but it has to be fully dissolved before you water. If you have not settled on a line, they sit side by side under Complete Nutrient Lines.

What you usually do not need in soil

On tap water in potting soil you rarely need CalMag: soil supplies calcium and magnesium, and tap water normally adds some more. That changes the moment you move to reverse osmosis. A root stimulator in the first weeks and enzymes if you plan to reuse the soil are the two add-ons that most often earn their place here.

Frequently asked questions

When do I feed for the first time?
On pre-fertilised soil, usually week two or three, and then at the lowest step of the chart. On a light mix, earlier. Let the plant set the timing rather than the calendar.

Can I use soil feed on coco?
Better not. A terra line assumes the substrate supplies calcium and magnesium, and coco does the opposite. You will almost certainly end up with a deficiency you then have to patch with separate feeding.

Can I reuse my soil?
You can, and enzymes exist for exactly that: they break down old root material so the structure stays open. Expect a second run to hold less feed, so you will start feeding earlier.