Potting mixes and fertilisers: caring for roots with COMPO

Start with roots and growing conditions

Potting mixes and fertilisers have different jobs. Before changing a mix or adding feed, review the species, root condition and product instructions. More water or fertiliser is not always the answer to slow growth.

Growing medium is more than soil

It anchors roots, holds moisture and provides space for air. The right balance retains enough water while allowing excess to drain. Choose for the plant rather than the largest bag.

A universal mix may suit many common plants, but not every species. Cacti and succulents need appropriate drying; many orchids need a very airy medium, and acid-loving plants have specific requirements. Check the particular COMPO product before buying.

Repot step by step

1. Choose a draining pot only a little larger than the previous one.
2. Add fresh growing medium.
3. Remove the plant carefully; gently loosen congested roots without breaking the rootball.
4. Maintain a similar planting depth.
5. Fill the sides and settle gently without compacting.
6. Water to the species' needs and drain. For cacti and succulents, adapt the first watering to root condition after repotting.

Empty retained water from saucers: drainage holes cannot help if the pot remains submerged.

Mix and feed are complementary

The mix is the root environment; fertiliser supplies nutrients. Some mixes already include an initial feed reserve. Read the packaging before adding more. Excess nutrients can damage roots rather than accelerate growth.

Choosing and timing fertiliser

Liquid feeds require the stated dilution. Granular or slow-release products follow different application methods. Match the formula to foliage plants, flowering plants or citrus and follow its label.

Feed according to active growth, species, light and temperature. If a plant wilts, check watering, drainage, light and possible pests before feeding. Fertiliser does not fix waterlogged roots or insufficient light.

Small errors to avoid

Avoid unchecked compacted old mix, oversized pots, guessed fertiliser doses and calendar-only watering. A suitable base, responsive watering and nutrients when needed matter more than collecting many products.

For help applying this to your plants, see our gardening advice session.

Related products and sources

• COMPO potting mix