Agapanthus.

Despite losing buds, it does look healthy. I’d repot it in only a slightly larger pot, possibly a bit deeper. Try not to disturb it too much.
They do like a rich compost mix, failing that mix some granular feed in with multi use compost.

Thank you for the advice J52.
I have bought a ceramic pot and put the plant directly in it using John Inness No. 3. It was difficult to find just the right size, but there was less than an inch of space all round so hope it will do. An Agapanthus really deserves a bright blue pot, but as all my others are shades of green, terracotta or black I went for a pale sage green.

I get plastic pots I am afraid, most pot pots are heavier than I want to lug about. I want to manage my back and my fingers to last a bit longer. I do have rather a lot of garden pots. 30 + then there is the rest of the garden .
We did not choose this plot it was the next one which would be ready on the before we could move in and get the kids into school for the next school term. It is a wee bit too big.
I do love it though.

I use mainly plastic pots too, as I can hardly lift the others if they contain heavy loam compost. I thought the Agapanthus deserved a ceramic one, and am even thinking of decoupage for it using an outdoor Mod Podge to seal it. It doesn't look like it will flower any more this year so thought I would add some flowers to the pot instead!

I have several different varieties of agapanthus around the garden . All are just starting to bloom . I have a mass of those tiny Pom Pom ones which are lovely but they’re totally in the wrong place because I just shoved them in to a spare bit of ground in panic to get them in. I will move them for next year. The rest are just mish mashed among everything else. They seem to love the overcrowding.

Oops sorry didn’t read the OP properly . Mine are not in pots although I am going to put those tiny ones into a pot for next year.

Oh! I’ve just watched Hampton Court Flower Show on I player. They had an agapanthus expert on, who said letting them become pot bound in order to flower was a myth!
He recommended repotting every 2/3 years and feeding with high potash feed every couple of weeks from spring through to the end of summer.
My potted ones have buds, just about to flower, but I will repot the smaller one early next year.

I have given my new one a tomato (high potash) feed, so I have done something right! I still have the last two Hampton Court programmes recorded so will watch.

nanasam lovely pic!
Mine aren’t as good as yours ?

Mine is Agapanthus Charlotte which is a decent height and the stems stay quite rigid. They are a very deep blue.
I still have thè lable from about seven years ago which is a miracle.

I planted three agapanthus in a large pot this spring.
Only one has come up and recently opened into a very sad little pale blue flower, not at all like I hoped.

These comments on garden stuff on here as are the BBC Gardeners World Forum, full of good info.

Agapanthus are easy to grow as long as you feed and water the ones in pots regularly and give the winter protection. Those in the garden seem to look after themselves. I live in the north of England but they seem very happy here and I have far too many of them so much so that my DH has referred to them as weeds?