Fertilising guide
How to fertilise Concrete Leaf (Titanopsis calcarea)— schedule & NPK
Also called Concrete Leaf, Concrete Leaf Plant, Jewel Plant, Jewel Weed, Limestone Mimicry.
More about concrete leaf
About Concrete Leaf
Titanopsis calcarea · also called Concrete Leaf, Concrete Leaf Plant · houseplant
Concrete Leaf (Titanopsis calcarea) is a tiny South African mesemb succulent whose warty, blue-grey rosettes mimic the limestone rubble it grows among. Give it bright direct sun, sharply draining gritty soil, and very sparing water — wet winters rot it. It is not ASPCA-listed; treat as mildly toxic and check with a vet.
Growth habit: Slow-growing, mat-forming dwarf succulent that develops clusters of low rosettes; the thick, spoon-shaped leaves are tipped with raised warty tubercles that mimic surrounding stone. Yellow to orange daisy-like flowers open on sunny autumn-into-winter days, typically from about two years old.
What fertiliser concrete leaf actually wants — and why
Concrete Leaf is a light-feeding succulent — a gentle, low-nitrogen feed a few times in growth keeps it plump without forcing the weak, stretched growth over-feeding causes.
A cactus and succulent formula or a diluted balanced feed with modest, even numbers. Avoid high-nitrogen plant foods — they make a succulent etiolate and grow soft, fracture-prone tissue.
For the language behind the three numbers on the bottle — what nitrogen, phosphorus and potassium each do — see the NPK ratio explained entry. The short version for concrete leaf: match the feed to the job the plant is doing right now, not to a generic “plant food” on the shelf.
How often to feed concrete leaf, and which months
Feeding only earns its keep while the plant is in active growth and can use the nutrients — pour feed into a dormant or low-light plant and it simply builds up as root-burning salt. For concrete leaf:
Feed lightly. Apply a diluted balanced or low-nitrogen cactus fertiliser about once a fortnight only during the active growing period in late spring through summer/early autumn; do not feed during dormancy. Over-feeding causes soft, distorted growth. Keep that to sparingly through the growing season between spring through early autumn (roughly March to September) and stop entirely once growth slows for winter.
The dormant-season rule matters more than the exact interval: skip feeding entirely when concrete leaf is resting. For the wider context on indoor feeding rhythms across the seasons, the houseplant fertiliser schedule walks through the year month by month.
What strength to mix for concrete leaf
Quarter to half strength at most for concrete leaf. Succulents take up very little, and a strong dose burns the fine roots before the plant can use it.
Feeding always goes onto already-damp soil, never dry roots — water concrete leaf first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the concrete leaf watering schedule.
Signs you are over-feeding concrete leaf
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for concrete leaf:
- Stretched, leggy, pale growth with widely spaced leaves.
- A white salt crust on the soil or around the pot rim.
- Brown, crisped leaf tips and edges.
- Soft, mushy tissue at the base — over-feeding plus damp soil rots it.
Signs you are under-feeding concrete leaf
- Uncommon — succulents tolerate lean conditions well.
- Very slow growth and dull, faded colour over a long period.
- Older leaves shed faster than new ones replace them in a tired old mix.
If the symptoms point at watering, light or roots rather than nutrition, the full concrete leaf care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Feed lightly enough and you rarely need to flush, but once a year run plain water through the pot of concrete leaf until it drains clear, and refresh the gritty mix every 2-3 years.
Organic vs synthetic feeds for concrete leaf
Organic options
A heavily diluted seaweed or worm-casting feed once or twice in summer. UK: a drop of Westland seaweed feed; US: quarter-strength Espoma Cactus! or Dr. Earth liquid. Fresh free-draining mix matters more than any feed.
Synthetic / liquid feeds
A dedicated cactus/succulent liquid at quarter to half strength — UK: Baby Bio Cacti & Succulent Drip Feeders or Westland; US: Miracle-Gro Succulent Plant Food or Schultz Cactus Plus.
Brand names are examples, not endorsements, and UK and US ranges differ — check the label’s own NPK and dilution rate, since formulations change.
Fertilising concrete leaf — frequently asked questions
What fertiliser does concrete leaf need?
A cactus and succulent formula or a diluted balanced feed with modest, even numbers. Avoid high-nitrogen plant foods — they make a succulent etiolate and grow soft, fracture-prone tissue. Concrete Leaf is a light-feeding succulent — a gentle, low-nitrogen feed a few times in growth keeps it plump without forcing the weak, stretched growth over-feeding causes.
How often should I feed concrete leaf?
Feed lightly. Apply a diluted balanced or low-nitrogen cactus fertiliser about once a fortnight only during the active growing period in late spring through summer/early autumn; do not feed during dormancy. Over-feeding causes soft, distorted growth. Feed lightly. Apply a diluted balanced or low-nitrogen cactus fertiliser about once a fortnight only during the active growing period in late spring through summer/early autumn; do not feed during dormancy. Over-feeding causes soft, distorted growth. Keep that to sparingly through the growing season between spring through early autumn (roughly March to September) and stop entirely once growth slows for winter.
What strength of feed for concrete leaf?
Quarter to half strength at most for concrete leaf. Succulents take up very little, and a strong dose burns the fine roots before the plant can use it.
What does over-feeding concrete leaf look like?
Stretched, leggy, pale growth with widely spaced leaves. A white salt crust on the soil or around the pot rim. Brown, crisped leaf tips and edges. Soft, mushy tissue at the base — over-feeding plus damp soil rots it. Feeding concrete leaf like a leafy houseplant is the classic error — it produces a flush of pale, stretched, floppy growth that never firms up and is prone to rot at the base.
Should I flush the soil of concrete leaf?
Feed lightly enough and you rarely need to flush, but once a year run plain water through the pot of concrete leaf until it drains clear, and refresh the gritty mix every 2-3 years.
Keep reading
- Concrete Leaf care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water concrete leaf — the watering schedule
- The houseplant fertiliser schedule — feeding through the year
- NPK ratio explained — what the three numbers on the bottle mean
- How to fertilise snake plant
- How to fertilise dracaena
- How to fertilise peperomia
- All 609 fertilising guides in the Growli library