What grows between

The terrace, walkway and low wall have been very satisfactory. However, the magic sand that was supposed to inhibit growth between the stones is losing its potency. Apart from the usual suspects which I'm pulling up pretty religiously are these three welcome visitors. In order, they are impatiens, growing under the table, beautiful moss which I hope will take over the terrace, and nicotiana which I can't resist allowing to grow a bit more.