Bittersweet memory of vine
For most of the year, the bittersweet vine is a wall of light-green foliage, or a netting-wire mesh of fine, bare twigs, but in autumn it reveals its beauty. It is grown mainly for its small berries which are something of a surprise package when they appear.
Like other vines, it is a scrambling and climbing plant. It is a strong grower capable of 10m or more in its native lands, but generally less than half that height here.
It can be used to grow up a tree, or planted against a fence. It looks better on a wooden fence or trellis than it does on a concrete wall, as it has a woodland air about it.
The pale green foliage of the bittersweet vine, or celastrus, is quite decorative in the way the leaves are held. They twist to face outwards towards the direction of most light. The leaves are broadly oval and rounded to some extent, some of them spoon-shaped.
The plant has loose bunches of small, greenish-white flowers, held inconspicuously amid the foliage. In the wild, the plants are male, with pollen, or female, without pollen, but plants with flowers carrying both male and female flower parts occur, and these can produce berries as a lone plant. These kinds have been selected for the garden trade.
After flowering, small, round, green berries begin to form and they grow to about pea-size. These turn yellow eventually, still largely tucked away amid the leaves. The leaves turn a lovely clear butter-yellow in October, but only last a couple of weeks, and then fall to reveal a showy constellation of small yellow berries in loose clusters.
In another week or so, the yellow skin of the berries splits into three sections to reveal three rounded, bright orange-red seeds. These are very pretty, set off by the yellow berries, open and yet to open.
This reveal is very like that of the related spindle tree, or euonymus, fruits which are larger, pink-red and open to reveal orange seeds. Lots of these spindles, which is a native tree, have been showing red leaf colour in roadside planting recently.
Bittersweet vine comes from Asia and has close cousins in North America. It is very hardy, and easy to grow in any ordinary soil that is fertile, though not too rich, and well-drained.
It likes sunshine because it comes from countries that have a warm summer. It can take some shade but won't flower quite so well and therefore produces a reduced show of berries.
Q When we moved into our house 21 years ago, we noticed that one particular rose bed wasn't doing well and we replanted it. For 16 years the roses were beautiful but recently we noticed that our original problem had returned. We have repeated the process and once again have dug in loads of compost. I've been told my roses were suffering from 'rose replant disease' and that I would have to sterilize the bed. Can you help? B O'Brien, Co Wicklow
A Rose replant disease affects rose bushes planted into soil where roses have been grown previously. Try using soil mycorrhizal preparations, which are available in some garden centres and online. And feed generously with rose food in March and July. Competing roots of a hedge or trees nearby can cause similar symptoms by using up soil moisture and nutrients.
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