Fertilising guide
How to fertilise Strawberry Foxglove (Digitalis × mertonensis)— schedule & NPK
Also called Merton foxglove, Strawberry foxglove.
More about strawberry foxglove
About Strawberry Foxglove
Digitalis × mertonensis · also called Merton foxglove, Strawberry foxglove · flowering
Strawberry foxglove is a sterile hybrid between Digitalis purpurea and D. grandiflora, valued as a reliable clump-forming perennial. It bears spikes of large, coppery strawberry-pink bells over glossy dark foliage and, being seed-sterile, lives longer than common foxglove and divides easily. It enjoys part shade and moist, rich soil; all parts are poisonous.
Growth habit: Clump-forming herbaceous perennial; sterile so it does not self-seed, instead persisting and slowly spreading from the crown, which can be divided.
What fertiliser strawberry foxglove actually wants — and why
Strawberry Foxglove is an easy, light foliage feeder — a half-strength balanced liquid feed through the growing months keeps it green without forcing weak, sappy growth.
A balanced general houseplant feed (roughly even N-P-K) is exactly right — it is grown for foliage, so steady, moderate nitrogen for healthy leaves is the goal, not a bloom or root formula.
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 strawberry foxglove: 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 strawberry foxglove, 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 strawberry foxglove:
Feed lightly in spring with a balanced fertiliser or compost mulch. It is not a heavy feeder; rich soil maintained with organic matter is usually sufficient. Treat that as sparingly through the growing season between spring through early autumn (roughly March to September); ease off in autumn and stop entirely in the low light of winter.
The dormant-season rule matters more than the exact interval: skip feeding entirely when strawberry foxglove 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 strawberry foxglove
Half strength is the safe default for strawberry foxglove — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
Feeding always goes onto already-damp soil, never dry roots — water strawberry foxglove first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the strawberry foxglove watering schedule.
Signs you are over-feeding strawberry foxglove
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for strawberry foxglove:
- Brown, crispy leaf tips and edges with no sign of underwatering.
- A white, crusty salt deposit on the soil surface or pot rim.
- Weak, pale, stretched new growth that flops.
- Lower leaves yellow and drop while the soil is correctly watered.
Signs you are under-feeding strawberry foxglove
- Uniformly pale or yellow-green leaves, oldest first.
- Noticeably small new leaves and stalled growth in good light and season.
- A generally tired, lacklustre look despite correct watering and light.
If the symptoms point at watering, light or roots rather than nutrition, the full strawberry foxglove care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of strawberry foxglove with plain water until it runs freely from the base every couple of months in the feeding season — it washes out the fertiliser salts that cause brown tips.
Organic vs synthetic feeds for strawberry foxglove
Organic options
A diluted seaweed or worm-casting feed, or fish emulsion if you can tolerate the smell indoors. UK: Westland or Baby Bio Organic, dilute seaweed; US: Espoma Indoor! or Neptune's Harvest fish & seaweed. Slow, gentle and hard to overdo.
Synthetic / liquid feeds
A general-purpose houseplant liquid at half strength — UK: Baby Bio, Westland Houseplant Feed or Phostrogen; US: Miracle-Gro Indoor Plant Food or Schultz. Convenient and fast-acting; the only risk is overdoing it.
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 strawberry foxglove — frequently asked questions
What fertiliser does strawberry foxglove need?
A balanced general houseplant feed (roughly even N-P-K) is exactly right — it is grown for foliage, so steady, moderate nitrogen for healthy leaves is the goal, not a bloom or root formula. Strawberry Foxglove is an easy, light foliage feeder — a half-strength balanced liquid feed through the growing months keeps it green without forcing weak, sappy growth.
How often should I feed strawberry foxglove?
Feed lightly in spring with a balanced fertiliser or compost mulch. It is not a heavy feeder; rich soil maintained with organic matter is usually sufficient. Feed lightly in spring with a balanced fertiliser or compost mulch. It is not a heavy feeder; rich soil maintained with organic matter is usually sufficient. Treat that as sparingly through the growing season between spring through early autumn (roughly March to September); ease off in autumn and stop entirely in the low light of winter.
What strength of feed for strawberry foxglove?
Half strength is the safe default for strawberry foxglove — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding strawberry foxglove look like?
Brown, crispy leaf tips and edges with no sign of underwatering. A white, crusty salt deposit on the soil surface or pot rim. Weak, pale, stretched new growth that flops. Lower leaves yellow and drop while the soil is correctly watered. Feeding strawberry foxglove year-round on a fixed schedule, including dark winter months, is the most common mistake — it cannot use the nutrients in low light and the surplus simply burns the roots and crusts the soil.
Should I flush the soil of strawberry foxglove?
Flush the pot of strawberry foxglove with plain water until it runs freely from the base every couple of months in the feeding season — it washes out the fertiliser salts that cause brown tips.
Keep reading
- Strawberry Foxglove care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water strawberry foxglove — 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 peace lily
- How to fertilise bird of paradise
- How to fertilise hoya
- All 1284 fertilising guides in the Growli library