Replacement or cure for failing for sea holly

[ScribblingPixie]

I planted five sea hollies in my garden & the first year they looked amazing. The second year only half really grew and flowered. This year none have. Slugs are a problem with their leaves, but they just don't look like they're doing much, just sitting about four inches high. I love their look, the colour, the sculptural quality and they way they stay through winter. A more experienced gardening advised me to give up on them. Should I? Or would something like seaweed fertiliser help? If not, can anyone suggest anything similar I can replace them with? Clay soil. The bed is sunny for about 8hrs.

Sea hollies are coastal plants, and like lots of sun, rather poor soils (because they don't like the competition with other plants they'd have in richer soils) and free draining soils - which rather rules out clay. So you either need to improve the drainage of your soil, or grow it in a container.

Yes, they must be the wrong plant for our soil, and the other plants around them have shot up so they're getting even less sun now. I'll try my best with the soil & give them one more year I think.