The Tree Mallow (Lavatera arborea) is a native plant on the south western coast of the UK including the whole of Wales’ coast. It is just coming into flower now, at the beginning of June, and will keep on flowering through to September. Bees love it.
It’s a true coastal plant: it doesn’t like to grow more than a couple of hundred metres from the sea. Both the native type and cultivated varieties are widely planted in seaside gardens.
Most books and catalogues describe the Tree Mallow as biennial, Wikipedia hedges its bets by saying it is annual, biennial or perennial! In fact, that’s about the best way to describe it: it isn’t fully hardy, it will die in hard winters, but it will keep growing through mild winters.
Tree Mallows are also susceptible to wind damage. Their root systems are surprisingly small for such a substantial plant (they grow to about 2m in height) and they are easily blown over. Also, although their stems can look quite woody and substantial, they are actually very pithy and liable to snap if they are not sheltered from strong winds.