Mature size & growth rate

How big does Aster 'Fellowship' (Symphyotrichum novi-belgii 'Fellowship') get?

Also called Fellowship aster, Michaelmas daisy, New York aster.

More about aster 'fellowship'

About Aster 'Fellowship'

Symphyotrichum novi-belgii 'Fellowship' · also called Fellowship aster, Michaelmas daisy · flowering

A classic New York aster (Michaelmas daisy) producing large, clear pink semi-double to double flowers on branching stems in early to mid autumn. A long-established cottage garden variety valued for its generous bloom. Not ASPCA-listed; treat as mildly toxic to pets as a precaution. Divide every two years to maintain vigour.

Mature size: 80-100 cm tall, 45-60 cm wide

Watch for — Aphids: Common in spring on new growth; address early before colonies establish to prevent distorted buds.

Indoor size vs how big it gets in the wild

Aster 'Fellowship' 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 80-100 cm tall, 45-60 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

Aster 'Fellowship' 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: apply a balanced fertiliser in spring as growth resumes. high-nitrogen feeds are best avoided as they worsen the mildew problem; a potassium-rich feed from midsummer improves disease resistance and flower quality.

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

How to keep aster 'fellowship' smaller

You are not stuck with the maximum size. For aster 'fellowship' specifically, these are the levers, in order of impact:

Divide the clump every year or two — splitting aster 'fellowship' 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 aster 'fellowship' 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 aster 'fellowship' bigger or faster

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

Give it a wider pot and let the clump fill it — width is exactly how this plant gets bigger.
Good light plus regular feeding maximises offset and runner production.
Leave plantlets and offsets attached and feed through the growing season for the fastest spread.

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

When aster 'fellowship' outgrows the room (or the pot)

"Too big" usually arrives as one of these signs for aster 'fellowship':

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 aster 'fellowship' repotting guide. If you want more of this plant instead of a bigger one, the aster 'fellowship' propagation guide turns prunings into new plants.

Aster 'Fellowship' size — frequently asked questions

How big does aster 'fellowship' get?

Aster 'Fellowship' reaches 80-100 cm tall, 45-60 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 aster 'fellowship' slow or fast growing?

Aster 'Fellowship' is a moderate grower. Expect three to six years to reach mature indoor size, gaining a steady amount each growing season. Aster 'Fellowship' 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 aster 'fellowship' 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 aster 'fellowship' smaller?

Divide the clump every year or two — splitting aster 'fellowship' 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 aster 'fellowship' grow bigger or faster?

Give it a wider pot and let the clump fill it — width is exactly how this plant gets bigger. Good light plus regular feeding maximises offset and runner production. Leave plantlets and offsets attached and feed through the growing season for the fastest spread.