Mature size & growth rate

How big does Strawberry Foxglove (Digitalis × mertonensis) get?

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.

Mature size: 60-90 cm tall, 30-45 cm wide

Indoor size vs how big it gets in the wild

Strawberry Foxglove stays fairly low but widens over time — it spreads into a bigger clump by offsets, runners or rhizomes rather than shooting upward. Indoors and in a pot, expect 60-90 cm tall, 30-45 cm wide. A pot, your light levels and a little pruning are what set the final size in a home, far more than the plant's theoretical potential.

Size here is about width, not height: the plant builds an ever-wider clump or sends out plantlets and runners while staying relatively short.

Growth rate and years to mature

Strawberry Foxglove is a moderate grower. Realistically, expect three to six years to reach mature indoor size, gaining a steady amount each growing season. Its feeding profile backs this up: 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.

Want this turned into the right next pot at the right moment? The pot size calculator and the strawberry foxglove repotting guide cover when and how much to size up — pot size is one of the biggest levers on how fast strawberry foxglove grows.

How to keep strawberry foxglove smaller

You are not stuck with the maximum size. For strawberry foxglove specifically, these are the levers, in order of impact:

Divide the clump every year or two — splitting strawberry foxglove is the main way to control its spread and refresh it.
Remove runners, plantlets or offsets as they appear if you want it to stay a single tight clump.
Keep it slightly pot-bound; a snug pot naturally limits how wide the clump can get.

The keep-it-smaller method, step by step

Lift the whole plant. Slide strawberry foxglove out of its pot in spring when the clump has filled it.
Split the clump. Tease or cut the rootball into two or more sections, each with healthy roots and growth.
Repot one division. Put a single division back in the original pot to reset it to a smaller size; pot or give away the rest.
Remove offsets as they form. Through the year, detach new runners or pups to stop it spreading again.

How to grow strawberry foxglove bigger or faster

If you want it to fill the space sooner, push the conditions rather than hoping — for strawberry foxglove the accelerators are:

Give it a wider pot and let the clump fill it — width is exactly how this plant gets bigger.
Brighter light speeds up clump and offset production noticeably.
Leave plantlets and offsets attached and feed through the growing season for the fastest spread.

Light is almost always the ceiling. The strawberry foxglove light requirements page covers exactly how bright a spot it needs to grow at its potential instead of stalling.

When strawberry foxglove outgrows the room (or the pot)

"Too big" usually arrives as one of these signs for strawberry foxglove:

The clump bulging over the pot rim or splitting the pot — the cue to divide, not to find a bigger room.
A dense centre that goes bare or tired while the edges keep spreading.
Runners or offsets escaping across the shelf or into neighbouring pots.

If it is the pot rather than the room, it is a repotting job, not a goodbye — see the strawberry foxglove repotting guide. If you want more of this plant instead of a bigger one, the strawberry foxglove propagation guide turns prunings into new plants.

Strawberry Foxglove size — frequently asked questions

How big does strawberry foxglove get?

Strawberry Foxglove reaches 60-90 cm tall, 30-45 cm wide when grown indoors. Size here is about width, not height: the plant builds an ever-wider clump or sends out plantlets and runners while staying relatively short.

Is strawberry foxglove slow or fast growing?

Strawberry Foxglove is a moderate grower. Expect three to six years to reach mature indoor size, gaining a steady amount each growing season. Strawberry Foxglove stays fairly low but widens over time — it spreads into a bigger clump by offsets, runners or rhizomes rather than shooting upward.

How long does strawberry foxglove take to reach full size?

Roughly three to six years to reach mature indoor size, gaining a steady amount each growing season. Light, pot size and feeding move that timeline more than anything else.

How do I keep strawberry foxglove smaller?

Divide the clump every year or two — splitting strawberry foxglove is the main way to control its spread and refresh it. Remove runners, plantlets or offsets as they appear if you want it to stay a single tight clump. Keep it slightly pot-bound; a snug pot naturally limits how wide the clump can get.

How can I make strawberry foxglove grow bigger or faster?

Give it a wider pot and let the clump fill it — width is exactly how this plant gets bigger. Brighter light speeds up clump and offset production noticeably. Leave plantlets and offsets attached and feed through the growing season for the fastest spread.