The Dianthus monspessulanus looks correct - is the fragrance a very sweet perfume (as opposed to the usual clove spice Dianthus fragrance?) One of my favourite plants... rather tatty-looking flowers, forms a large mat in time, wonderful because it perfumes the air in summer.
Wow, South American cacti, June! Well done! I take it your greenhouse isn't heated?
Troughs are another way to grow plants that need sharp drainage, lean soil or special conditions in general, without making in-ground rock garden beds:
