Forget-me-not - I just threw a packet of seeds in and most of them came up; hopefully they'll now self-seed all round the garden as I love these cheery blue flowers!
I've had some problem with caterpillars recently - I got some great advice from Lyn Bagnall who's written a book on organic gardening - see favourite book list. She's one clever lady... here's what she had to say;-
It sounds as though your caterpillars are those of the cabbage white butterfly as they are also very fond of nasturtiums and some plants other than the cabbage family. If your plants are being attached ferociously and it is difficult to see the pests, spray the affected areas of the plants (especially along the stems) with a product called Dipel. This product is a bacteria that only affects caterpillars. It is safer than using a garlic spray which only kills very small caterpillars but can also kill some beneficial insects. If there are only a few caterpillars eating your plants - the best way to get rid of them is to don some gloves and squash them on the leaves. The dead grubs on the leaves are said to deter moths laying more eggs on these plants. Also look under the leaves, and remove any eggs. If the infestation is bad and you have missed some eggs, you may have to repeat the spraying in a week or so.In my book, you will notice in The Organic Approach to pest control (on pages 413-4) I emphasise that stressed plants are more vulnerable to pests and disease, and that building healthy soil will reduce pest and disease problems, dramatically. Some gardeners find this very hard to accept but we have proved this over and over again. Spraying the pests will only solve the problem temporarily. Looking for the reason why your plants are stressed will prevent future problems. I have noticed that cabbage white butterflies often attack plants where the soil is too acid for the plants' good health. In this case, watering in some dolomite (a handful to a full watering can) should show an improvement in plant health in a week or so. Repeat in a week in soil contains very little organic matter. Nasturtium and Calendula are two species that don't need a very rich soil and too much fertiliser can create soft sappy growths that is attractive to pests.