It is a slow process, apart from having to grub up the wretched weedy vetch, as I go round deadheading before cutting the old flowering stems down. They are destined for the compost heap, but I don't want the compost full of Agapanthus and Dierama seeds because the heap won't get hot enough to kill them. That sounds ungrateful. Who could object to having more elegant South African flowers for free? Indeed, I love both of them, but that's not to say I want them scattered through every border I ever use the compost on. Both are prolific self seeders, the seeds of the Agapanthus like pointed black peppercorns and the Dierama seeds solid, glistening, orange-brown, angular bodies a bit smaller than a match head. The old flower heads both went in an old compost bag ready to go in the brown council recyling bin, along with the spent flowering stems of the evening primroses. Even so I shall be hauling dozens of unwanted Dierama seedlings out of the gravel.
The evening primroses self sow with irrepressible enthusiasm. I don't know for sure what species they are, since I grew them from seed collected from plants growing on the beach at Dunwich. Or rather, I grew their ancestors and they have kept going ever since by seeding, for they are biennials. They fit the description of Oenothera biennis, originally a north American species but one which is widely naturalised in temperate regions elsewhere, according to Wikipedia. I like them. They grow enthusiastically in the gravel with no supplementary watering or feeding, which is more than you could say of about ninety-nine per cent of plants offered for sale in the average garden centre, and they flower over a long period from high summer into autumn. The flowers are yellow, but since I am not somebody who regards disapproval of yellow flowers as a badge of good taste that doesn't matter. I have seen goldfinches feeding on the seeds in late winter, which is nice. But they do seed. Boy, do they seed. Fat little lettuce coloured rosettes of leaves come up in abundance all over the gravel and have to be prised out several times every year. I am not even taking the old flowering stems up to the bonfire heap this time, to avoid having a new colony forming near the compost bins, but snipping them up in situ and stuffing them straight into the bag of rubbish.
I will not groom the dead, brown leaves out of the Watsonia pillansii for now. This is another South African, and I think the gravel is drier than it would like since leaves always seem to be going brown. Either they are too dry or they are incorrigably messy growers. They have self sown as enthusiastically as the Dierama since I first planted them out a couple of years ago, but I won't start counting my chickens until some of the babies have reached flowering size. Watsonia is not the hardiest thing for a UK garden, and I shall leave the old leaves in place to help protect the crowns until spring.