A white foxglove is standing guard over the entrance to the house and with impeccable timing it has been joined by the frothy white umbels of cow parsley and the perky little Mexican daisy Erigeron karvinskianus.

These are a trio that so perfectly embellish the entrance to the back door that I wish that I had thought of it myself. As it is this pretty trio have chosen this spot for themselves and frankly the only action on my part has been to stand back and admire.

All three are rampant ‘self-seeders’ and all three are welcome in my garden wherever they may place themselves. The little daisy prefers cracks between paving stones and the edge beneath steps. I think that the original was bought as a pot plant many years ago but it has seeded around to my great delight because it will continue flowering long into the autumn.

Some years ago I was given an entire tray of white foxglove seedlings which I spread around the garden and because they are bi-annuals forming a neat rosette of leaves in the first year before flowering and setting seed in the second year where the cycle begins all over again, there is a perpetual supply of these short lived beauties.

The last in this trio is of course a native wilding but it is also my favourite flower and although you can go to a garden centre and buy Anthriscus sylvestris ‘Ravenswing’ which is its Latin name followed by a description which tells you that unlike the cow parsley frothing over our lanes it distinguishes itself by displaying its white umbels above dark purplish black stems and leaves.

They may look dramatic but I infinitely prefer our common wildflower in all its prolific glory. It has made itself at home beneath the birches and all along my hedgerows and has wandered into the orchard where it complements the very lovely late flowering Narcissus poeticus recurvus with its white petals surrounding a tiny red rimmed lemon yellow cup.

There is no doubt that self-seeders can be a boon to gardeners for my garden would be the poorer without such pretty annuals as forget-me-nots and the perennial hardy geranium ‘Bill Wallis’ whose small, purple flowers appear in unexpected places. Still there is no getting away from the fact that they can also be a curse and your point of view and mine is inevitably coloured by the thuggish behaviour of some such as comfrey that has become a rampant weed.

I bought lemon balm in haste to fill a hole in the border and have repented at leisure as it has seeded itself everywhere. Its one virtue is that as I pull it up by the handful two eager donkeys happily dispose of it.

You can, of course, give self-seeders such as the white umbellifer ‘Ammi’ a shorter summer flowering cow parsley look alike, a hand. After it has finished flowering and set seed I gather its spent heads with their brown seeds and simply shake them out where I would like to see them the following year. An easy and satisfying job.