They are not a bulb. They have a fleshy root much like daylilies or some iris do. I believe they do better potbound - mine (a white flowered form similar to Peter Pan) has been in the same container for over five years. It gets very little fertilizing, also. And it blooms just fine :-) It is a quite a bit larger container than 14" however, which could make a difference.

One other thought....I wouldn't consider agapanthus very container hardy for a MA winter. "Cool" shade maybe just a bit too cold??

When we had a freeze of 14 degrees the agapanthus turned to mush above ground, but recovered from the roots. Too much shade and the bloom is greatly reduced, too much sun and the plant turns a sickly yellow, but it continues to bloom. Here they are prolific reseeders. Mine are being grown in the ground and are never fertilized, but in a container it would be needed. Peter Pan is not nearly as strong as the regular species. Al

They can be too root-bound, even when grown in the ground. The clumps start to push out of the soil, become very straggly and don't perform too well at all. The roots may even start growing on the roots and stems of the layer below - 'interesting' to unravel.

In addition to fertiliser, it may be useful to topdress them with fresh potting mix and/or well-rotted leaf mould if the container has become full of roots.

If yours are evergreens then a touch more sun over winter would probably be helpful for setting up the following season's flowers.

Al: Yes. Just like Hedychium spp. And those wretched papery seeds land in every crack. Two downpours later and the seeds are sending down fat white roots for heaving up the tarseal and concrete. IMO deadheading a long driveway's worth is the sort of job reserved for Bad People (or jobbing gardeners...) But the dwarf potted varieties are quite nice. I have a miniscule soft spot for 'Tinkerbell'.

I've been wanting to obtain some Agapanthus for container growing... it would have to winter indoors, and couldn't be too large... what dwarf types would you all recommend? I've seen Peter Pan in photos, but have never run into Tinkerbell.

Would it be better to purchase live plants, or is it an easy plant to grow from seed?

They grow easily from seed,and if you are not in a hurry, or plants are not available locally, I would certainly grow from seed. Al

How can you tell if they are evergreen or not? Can I keep them in the cellar where it is about 50 degrees or does it have to be colder?

Here our normal low temperature is seldom below 27 degrees and 27 is only 4 or 5 times during the winter. They thrive in these temperatures, but I am not sure they would tolerate the light available in the cellar. They are evergreen and look the same year around. Al

I have read that some varieties bloom better somewhat crowded or potbound, but that there are other varieties that need to be divided every so often. I have Ellamae and it needs dividing.