Posted: 15/06/2014 at 17:32
This is one of three Acanthus Mollis I grow. Firstly, its huge and I only fed it once in its lifetime last year, because it was looking less than vigorous. The leaves were yellowing and it was reluctant to flower. Saying that, it is over 15yrs old and I can't remmeber a single year it hasn't flowered. I never planted in any kind of special soil since back in those days, everything went into my sandy builder's rubble soil whether they liked it or not.
Secondly, It's at the front corner of my first border near the house. I have never regretted planting it there although this year, its over extended itself and will get a bit of a prune at some point. It's architectually splendid with so much to offer the eye and to be honest, the only problem it has is midday sun. They tend to sink a bit in terrific heat but perk up again by late afternoon.Perhaps, yours is in too much shade? It's got to be a reasonable amount of sun I've read.
Thirdly, be warned! These things are invasive if you are not a clean freak like me. The massive flower spires will drop large seeds close to the plant that form baby plants and is hard to dig our since each tiny bit of root will form an entiirely new plant! Cut off any flower spikes in the autumn, or be diligent at the plant base come early spring. I failed to do the hoovering properly this spring and my plant grew wider as a result.
I think these add majesty to the garden, but each to their own