Mature size & growth rate

How big does Delphinium grandiflorum 'Blue Butterfly' (Delphinium grandiflorum 'Blue Butterfly') get?

Also called Blue Butterfly delphinium, Chinese delphinium.

More about delphinium grandiflorum 'blue butterfly'

About Delphinium grandiflorum 'Blue Butterfly'

Delphinium grandiflorum 'Blue Butterfly' · also called Blue Butterfly delphinium, Chinese delphinium · flowering

'Blue Butterfly' is a dwarf Chinese delphinium grown for masses of brilliant gentian-blue flowers on airy, branching stems in summer. Far shorter than border delphiniums at 30-40 cm, it suits fronts of beds, pots and gravel gardens, needs no staking, and flowers fast from seed. Like all delphiniums, it is toxic to cats and dogs.

Mature size: 30-40 cm (12-16 in) tall and 25-30 cm wide; dwarf and self-supporting, needing no staking.

Watch for — Slugs and snails: Tender new shoots and seedlings are vulnerable in spring. Protect emerging growth with barriers, traps or wildlife-safe controls.

Indoor size vs how big it gets in the wild

Delphinium grandiflorum 'Blue Butterfly' reaches its full size within one growing season — there is no "long-term" size, just how big it gets before you harvest or it dies back. Indoors and in a pot, expect 30-40 cm (12-16 in) tall and 25-30 cm wide. In the ground with no restriction it is a completely different plant — dwarf and self-supporting, needing no staking. — which is why the pot, the light and the pruning matter so much for the size you actually end up with.

It sizes up fast and once, racing from seedling to full size in a single season; after cropping it is finished, so size is a within-season question.

Growth rate and years to mature

Delphinium grandiflorum 'Blue Butterfly' is a moderate grower. Realistically, expect a single growing season — it reaches full size in one year, then is done. Its feeding profile backs this up: lighter feeders than tall delphiniums. a balanced fertiliser in spring and a deadheading-time feed encourage repeat bloom; avoid overfeeding, which makes lax growth on this naturally compact plant.

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

How to keep delphinium grandiflorum 'blue butterfly' smaller

You are not stuck with the maximum size. For delphinium grandiflorum 'blue butterfly' specifically, these are the levers, in order of impact:

Choose a compact or dwarf variety of delphinium grandiflorum 'blue butterfly' from the start — that is the most reliable size control for an annual.
Grow it in a smaller container to naturally limit how large it gets.
For some crops, pinching or pruning the growing tips keeps the plant shorter and bushier.
Sow a little later or space plants closer if you specifically want smaller individual plants.

How to grow delphinium grandiflorum 'blue butterfly' bigger or faster

If you want it to fill the space sooner, push the conditions rather than hoping — for delphinium grandiflorum 'blue butterfly' the accelerators are:

Full sun, warm soil and steady water are what drive a crop to full size fastest.
Sow at the right time for your zone so it gets the whole season to size up.
Feed appropriately for the crop and never let it check (stall) from drought or cold.

Light is almost always the ceiling. The delphinium grandiflorum 'blue butterfly' light requirements page covers exactly how bright a spot it needs to grow at its potential instead of stalling.

When delphinium grandiflorum 'blue butterfly' outgrows the room (or the pot)

"Too big" usually arrives as one of these signs for delphinium grandiflorum 'blue butterfly':

It sprawls beyond its bed or container before harvest — usually a spacing or support issue.
It flops or needs staking once it hits full height.
Once it has fruited or bolted, it is at its final size for good — the next plant is a new sowing.

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

Delphinium grandiflorum 'Blue Butterfly' size — frequently asked questions

How big does delphinium grandiflorum 'blue butterfly' get?

Delphinium grandiflorum 'Blue Butterfly' reaches 30-40 cm (12-16 in) tall and 25-30 cm wide when grown indoors, and far larger where it grows unrestricted (dwarf and self-supporting, needing no staking.). It sizes up fast and once, racing from seedling to full size in a single season; after cropping it is finished, so size is a within-season question.

Is delphinium grandiflorum 'blue butterfly' slow or fast growing?

Delphinium grandiflorum 'Blue Butterfly' is a moderate grower. Expect a single growing season — it reaches full size in one year, then is done. Delphinium grandiflorum 'Blue Butterfly' reaches its full size within one growing season — there is no "long-term" size, just how big it gets before you harvest or it dies back.

How long does delphinium grandiflorum 'blue butterfly' take to reach full size?

Roughly a single growing season — it reaches full size in one year, then is done. Light, pot size and feeding move that timeline more than anything else.

How do I keep delphinium grandiflorum 'blue butterfly' smaller?

Choose a compact or dwarf variety of delphinium grandiflorum 'blue butterfly' from the start — that is the most reliable size control for an annual. Grow it in a smaller container to naturally limit how large it gets. For some crops, pinching or pruning the growing tips keeps the plant shorter and bushier. Sow a little later or space plants closer if you specifically want smaller individual plants.

How can I make delphinium grandiflorum 'blue butterfly' grow bigger or faster?

Full sun, warm soil and steady water are what drive a crop to full size fastest. Sow at the right time for your zone so it gets the whole season to size up. Feed appropriately for the crop and never let it check (stall) from drought or cold.