Snake's heads in the grass
Two years ago I planted snake’s head fritillary bulbs, mostly in the flower borders. This year they have produced masses of seed heads. Each head contains hundreds of seeds. What should I do with them now? Will they develop into bulbs?
Derek Allen, Montrose
These wonderful little fritillaries grow naturally in damp meadows and on flood plains, and I think they look and fare best in gardens if these conditions are replicated as closely as possible: i.e. if grown in a part of a moist lawn that is allowed to be less-than-kempt for the first half of the year. In the right conditions they cast their seed around naturally and will in time form a long-lasting, expanding colony – something they are unable to do if planted in a regular, well-tended flower border.
I think you should in future make a feature of your fritillaries in this way – designate an area in which to strew the fresh seed around in mown grass now (or even in early autumn) and let nature take its course: next year, single (but quite recognisable) skinny leaves will appear in the grass. These will die off by mid-summer as the tiny, developing bulbs go into dormancy and the grass area can be cut thereafter.
After three or so years of sticking to this mowing regime (while taking care not to mow too closely or too often once the seed has cast itself around), you will be rewarded with a greatly expanded fritillary population. I appreciate that this sort of “gardening” is not to most perfection-seeking lawn-keepers’ taste.
Alternatively, sow the seeds now on the surface of pots of gritty compost, covering them thinly with additional fine grit. Keep the pots out of the sun in a cold frame until the leaves appear, then nurture them in and out of dormancy for two years. By which time the little bulbs will be big enough for autumn planting: in your turf, preferably.
Wasps in compost?
I have a wasps’ nest in my compost bin, the plastic type. If I get someone to get rid of it, does it mean the compost will be contaminated?
Jakki Antrobus, via email
Before you take any action, make sure these are wasps, not solitary bees, which are much-valued as pollinators. Whichever they are, you could do nothing at all but just let them get on with it. The bin is clearly peaceful enough to be considered a suitable site for nest-building, which implies that you are not actively using it.
The nest will be vacated by late autumn and can simply be stirred into the general mix which will not have been contaminated in any way. If necessary you could perhaps make a new, temporary compost container (an old lidded plastic bin with holes in the bottom) and combine the contents later.
I can think of two non-chemical alternatives, should the interlopers indeed be wasps. Determine the entry point – there will be a constant stream of visitors, so this should be easy. At night go out with a torch and block it up. Or (this requires bravery), open the bin and dump in a large amount of grass clippings and slam the lid back on. The temporary extreme heat the clippings generate will hopefully see them off.
Restrain the bride
My gorgeous exochorda, which flowers beautifully every year, has now started to encroach on other shrubs. I have been unable to find any advice as to when to prune it and would be grateful for your guidance.
Ruth Shirley, Ayot St Peter, Herts
I share your passion for this early summer beauty (Exochorda x macrantha 'The Bride’). Yours does look a little overgrown – as you say, through lack of pruning. But it also looks absolutely magnificent, and it may be time to consider whether its neighbours (which I could not precisely identify) might be more controlled or even culled so that you could let 'The Bride’ occupy centre stage unchallenged.
Pruning could not be simpler. Simply remove old, less productive wood as well as all the spent-flowery branches just as its performance comes to a close in mid to late-May. It will then make a lot of new growth that can be tentatively thinned if necessary in autumn (and I mean tentatively), to recreate a perfect soft weepy shape that will bear cascades of flowers the following season.
If you prune like this now, you may go too far. So this year (since it is already late) be selective about how much you do.
Minding one’s own
Several readers have emailed about a tiny-leafed weed that is invading their lawns and borders, even sneaking along cracks in paving stones. The weed is Helxine soleirolii, commonly known as mind your own business or baby’s tears, and was originally grown as ornamental ground cover in 19th-century glass houses, from whence it long ago “escaped”. I am afraid the outlook is not good for those with it in their lawns, unless they are prepared to use a total greenery-killer such as Round Up – probably more than once, since helxine has a nasty habit of re-appearing after one treatment and will grow from any tiny scrap. This means, of course, that it will be necessary to re-seed the lawn once the coast is clear.
The worst thing you can do is try to rake the weed out of grass, since this will merely spread it around. I have heard that where helxine is creeping along cracks, success can be achieved with the use of a hand-held steamer.
I am always alarmed to see this superficially decorative thing, tiny-leafed and fashionably minimalist, on sale as a house plant – do buyers realise they could b playing with fire?