Fertilising guide
How to fertilise Sempervivum montanum (Sempervivum montanum)— schedule & NPK
Also called Mountain houseleek.
More about sempervivum montanum
About Sempervivum montanum
Sempervivum montanum · also called Mountain houseleek · houseplant
Sempervivum montanum is a true alpine houseleek with small, soft-haired, resin-scented green rosettes that hug the ground. Native to high mountain screes, it is exceptionally cold-hardy and craves full sun and sharp drainage. It clusters into tight cushions via offsets, produces star-shaped reddish-purple flowers, and rots quickly in damp, shaded, or rich conditions.
Growth habit: Evergreen, cushion-forming alpine succulent. Small fuzzy rosettes multiply tightly by short offsets to build dense, low mats. Each rosette is monocarpic, flowering once on a short stalk before dying and being replaced by its chicks.
Watch for — Etiolation in low light: Too little sun makes the compact rosettes stretch and pale. This species needs full sun; relocate to the brightest position or add supplementary lighting to keep the cushion tight.
What fertiliser sempervivum montanum actually wants — and why
Sempervivum montanum 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 sempervivum montanum: 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 sempervivum montanum, 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 sempervivum montanum:
Essentially none. An alpine adapted to poor scree, it resents feeding; at most a single very dilute low-nitrogen succulent feed in spring. Rich nutrients produce soft, floppy, rot-prone 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 sempervivum montanum 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 sempervivum montanum
Quarter to half strength at most for sempervivum montanum. 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 sempervivum montanum first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the sempervivum montanum watering schedule.
Signs you are over-feeding sempervivum montanum
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for sempervivum montanum:
- 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 sempervivum montanum
- 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 sempervivum montanum 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 sempervivum montanum until it drains clear, and refresh the gritty mix every 2-3 years.
Organic vs synthetic feeds for sempervivum montanum
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 sempervivum montanum — frequently asked questions
What fertiliser does sempervivum montanum 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. Sempervivum montanum 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 sempervivum montanum?
Essentially none. An alpine adapted to poor scree, it resents feeding; at most a single very dilute low-nitrogen succulent feed in spring. Rich nutrients produce soft, floppy, rot-prone growth. Essentially none. An alpine adapted to poor scree, it resents feeding; at most a single very dilute low-nitrogen succulent feed in spring. Rich nutrients produce soft, floppy, rot-prone 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 sempervivum montanum?
Quarter to half strength at most for sempervivum montanum. Succulents take up very little, and a strong dose burns the fine roots before the plant can use it.
What does over-feeding sempervivum montanum 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 sempervivum montanum 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 sempervivum montanum?
Feed lightly enough and you rarely need to flush, but once a year run plain water through the pot of sempervivum montanum until it drains clear, and refresh the gritty mix every 2-3 years.
Keep reading
- Sempervivum montanum care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water sempervivum montanum — 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 2464 fertilising guides in the Growli library