Depending on the variety you have, SJW is not well suited for a container, as it will get 4 foot tall at bloom stage. I believe all SJW are perennials, and perennials do not usually bloom their first year so if you get a new plant in bloom from a nursery, it was probably forced bloom, and may take a year of two to naturize itself, to get its own internal clock ticking again.
If you are planning on using these be sure to get a positve ID on on the Latin anme, not just common SJW. The medicinal kind is Hypericum perforatum, and here's a link for you to peruse. Enjoy! Lynn

Here is a link that might be useful: SJW

Two summers ago, our landscaper planted two 4' x 6' areas with St. Johnswort Clusiaceae (Garcina) -- Hypericum x 'Hidcote'. One patch bloomed bountifully all summer, with 3" flowers. The other patch just leafed out. Last year, both patches looked very healthy, but not one flower. This year, nothing so far, although the leaves are healthy. I fertilize it every two weeks. Any ideas? Should I be thinning it? Dead-heading it?

Thanks for any help, Jan

Jan, Hidcote is a tough shrub that will live for many years in any ordinary garden soil with no special care. One mature plant could fill a 4 x 6 space. It does not need fertilising every two weeks, more like every two years if at all. My guess is that it is putting on foliage at the expense of flowers because of the excess feeding.

Rai, as herbalyn says, there are many St John's Worts ranging from tiny rock plants to massive shrubs. So unless we know which one you have it is hard to advise on care.

My SJW is currently putting out small white and yellow flowers. They look like daisies, but they're only half an inch across. They get lots of sun and I never water them. They "thrive on neglect". It rained last night. Watch yours for the next couple of weeks. Good luck!

If they're white and yellow and look like daisies I don't think they're St John's Wort of any sort, Jannie. Maybe Feverfew?

I've had St. John's Wort for several years with all but one season producing very disappointing blooms ... buds pop up, but only a handful of flowers emerge. Given that it's considered an invasive in some parts--and it's really starting to spread all over the place, should I just pull it all out and put in something else? I love the flowers, but so far not worth it.

brassl - what sort of SJW do you have? Check my reply back on June 11 2007.

I also have St Johnswort that has not bloomed ...for three years. I don't give it added attention, it gets full about 6 hrs of sun and it's in fertile, loamy, well draining soil.

Are you sure it's St. Johnswort?

FataMorgana

I think SJW does not need lots of food and attention.
If you give lots of fertilizer, water..probably it wont flower.

And, yes it is aggressive but I dont consider it INVASIVE. But look at it as a medicin cabinet in your garden. I have also Lemon Balm, which is a wonderful medicinal herb that is also aggressive. That is no problem. I can eliminate all the unwanted SJW and LBs in less than 30 minutes.