Fertilising guide

How to fertilise Woolly Foxglove (Digitalis lanata)— schedule & NPK

Also called Woolly Foxglove, Grecian Foxglove, Digitalis.

More about woolly foxglove

About Woolly Foxglove

Digitalis lanata · also called Woolly Foxglove, Grecian Foxglove · herb

Woolly Foxglove is a biennial or short-lived perennial from the Balkans and southeastern Europe, cultivated commercially as the primary source of the cardiac glycoside digoxin. It produces dense spikes of creamy-white, brown-veined tubular flowers in its second year. All parts are highly toxic. Suited to sunny, well-drained borders; moderately drought-tolerant once established.

Growth habit: Biennial or short-lived perennial forming a basal rosette in year one, flowering spike in year two

What fertiliser woolly foxglove actually wants — and why

Woolly Foxglove is a soft, fast leafy herb that you harvest hard — a modest balanced feed keeps tender growth coming without tipping it into bland or bolting.

A balanced general feed (even N-P-K) at modest strength — enough nitrogen to keep replacing the leaves you pick, but not so much that flavour thins or it bolts to seed.

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 woolly 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 woolly 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 woolly foxglove:

Apply a low-nitrogen, phosphorus-rich fertiliser (e.g. 5-10-5) in early spring to support root and stem development before flowering. Avoid high-nitrogen feeds which promote lush foliage but reduce flowering in the second year. In practice: a balanced liquid feed every few weeks through the main growing and harvesting season (spring through early autumn), more often the harder you are picking it.

The dormant-season rule matters more than the exact interval: skip feeding entirely when woolly 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 woolly foxglove

Half strength is a sensible default for woolly foxglove — enough to fuel regrowth after cutting, gentle enough that the leaves stay aromatic rather than watery.

Feeding always goes onto already-damp soil, never dry roots — water woolly foxglove first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the woolly foxglove watering schedule.

Signs you are over-feeding woolly foxglove

Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for woolly foxglove:

Fast, soft, pale growth with diluted, less aromatic flavour.
Early bolting (running to flower) and a bitter edge.
Salt crust and scorched tips on container plants.

Signs you are under-feeding woolly foxglove

Pale, slow regrowth after cutting and small leaves.
A tired, stalled plant that cannot keep up with harvesting.
Yellowing older leaves in a long-spent pot.

If the symptoms point at watering, light or roots rather than nutrition, the full woolly foxglove care brief covers soil, humidity and the common problems for this species.

Flushing and leaching the salts

Pot-grown woolly foxglove builds up feed salts quickly — water until it drains each time and flush the pot with plain water every few weeks, especially on a sunny windowsill.

Organic vs synthetic feeds for woolly foxglove

Organic options

A diluted seaweed feed or worm-casting tea keeps soft growth coming without overdoing it. UK: dilute seaweed or Westland; US: Espoma Garden-tone or Neptune's Harvest. Gentle, hard to overdo, flavour-friendly.

Synthetic / liquid feeds

A balanced liquid feed at half strength through harvesting — UK: Phostrogen, Baby Bio or Westland; US: Miracle-Gro all-purpose at half strength. Fast regrowth; just do not overdo the nitrogen.

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 woolly foxglove — frequently asked questions

What fertiliser does woolly foxglove need?

A balanced general feed (even N-P-K) at modest strength — enough nitrogen to keep replacing the leaves you pick, but not so much that flavour thins or it bolts to seed. Woolly Foxglove is a soft, fast leafy herb that you harvest hard — a modest balanced feed keeps tender growth coming without tipping it into bland or bolting.

How often should I feed woolly foxglove?

Apply a low-nitrogen, phosphorus-rich fertiliser (e.g. 5-10-5) in early spring to support root and stem development before flowering. Avoid high-nitrogen feeds which promote lush foliage but reduce flowering in the second year. Apply a low-nitrogen, phosphorus-rich fertiliser (e.g. 5-10-5) in early spring to support root and stem development before flowering. Avoid high-nitrogen feeds which promote lush foliage but reduce flowering in the second year. In practice: a balanced liquid feed every few weeks through the main growing and harvesting season (spring through early autumn), more often the harder you are picking it.

What strength of feed for woolly foxglove?