HELEN YEMM THORNY PROBLEMS
This week: cosmos complications, a domestic disagreement over a bramble, and the merits of various types of mint
My daughter, granddaughter and I have grown some fantastic cosmos plants, but very few of them have flowered – although the foliage has been stunning. I fed mine with tomato food to try to encourage flowers, but to no avail. It isn’t the first time this has happened, so what can we do differently next year?
LYNNE MILLER – VIA EMAIL
Some years ago, fellow writer Mary Keen, similarly frustrated by her non-flowering cosmos ‘Dazzler’, did some painstaking sleuthing on this very subject. The article she wrote for Telegraph Gardening is still available online, easily found by googling “Mary Keen Cosmos”.
Put briefly, it would seem tomato food is not in this case the answer, as you and others have found. The problem of all-leaf-no-flower cosmos has more to do with rather variable seed, which most companies import from Africa, where light levels and growing conditions are obviously very different.
Cosmos can, apparently, revert to something called “short day flowering”, a condition where plants will only flower once hours of uninterrupted darkness are above a critical level. One solution may be to save seed from those plants that flower in July, rather than those that limp towards flowering (which some leafy plants do) just before the frosts. Mary’s article covers this complicated subject in more depth than I can here.
The kitchen view from the house we have recently taken on is of a small, rather plain orchard. I think a whitestemmed bramble would cheer up the winter view but my partner is worried that its prickliness would become a
TIP OF THE WEEK
one to go for to enliven a pot of boiling new potatoes, mix in to mojitos or add to a jug of Pimms.
Variegated apple mint has smaller leaves that are supposed to smell of pineapple (though I don’t get that) and its foliage makes an ornamental, slumpy component in a container (which I do).
Now it gets complicated: Bowles mint, (a
M suaveolens/spicata hybrid called M x villosa var alopecuroides) may
spreading liability. I would appreciate some guidance as to how to maintain it as a neat “feature” so that I can reassure him it won’t take over the orchard.
RUTH CHARD – VIA EMAIL
I agree. The white stems of Rubus cockburnianus, or slightly more refined R thibetanus, would make an impressive winter statement among the leafless orchard trees. As long as you grow one as a clump that you can walk and work around rather than growing it mixed in to a hedge, the maintenance is fairly simple: every spring, donning a wax jacket and gauntlets, either cut all the stems to within a few inches of the ground so your bramble annually produces a brand new crop of ghost-white stems, or, if you want to maintain a measure of all-year-round structure, halve the just, in flavour terms, be more “all-purpose” in the kitchen. But it is far taller and chubbier than
M villosa and not really suited to life for more than a year in a container.
Mint is a natural sprinter when let loose in a garden, and even spearmint in a
1ft (30cm) wide pot will need a severe sort-out/ replant every two years as its vigorous runners are forced to circle around the edge of its container and the central core of the plant weakens and dies off.
number of stems, removing the oldest, ugliest and most damaged while letting the rest mingle amid the new growth.
Also, to prevent the clump from straying, in late summer be sure to cut off the tips of any arching shoots heading towards the ground, where they would otherwise root and eventually shoot, making “satellite” plants (as regular brambles do).
POT LUCK Herbs such as basil are better in pots than most mints, which like space