morning glory not growing tall

I dont know what variety you use but I have used Grandpa Otis to great success every year. Lovely purple colour. It is a tender plant and should be planted out after the frosts but you could even put the seeds in when the weather warms up.

That is strange, Anitac. They usually grow up to 6' trained up a wigwam or trellis. I grow mine alongside my sweetpeas, so they get fed weekly - maybe that would help? Mine are still in pots in the greenhouse until the frosts are over.

I had one last year that grew pretty big. It was in a sunny position on an open type fence, and the soil is very well drained being sandy. I watered as much as possible in the very hot weather and it thrived. It was a white one. This year I am trying with blue and pink ones and hope for similar success. They are outside now since we should not get any more frost.