For years now, I have been watching the Blackbirds feeding in the garden, particularly at this time of year when the focus of their attention has been the Rowan berries. In the last garden we had five or six different varieties, chosen for their special characteristics – tree shape, leaf shape, flowering, fruiting, autumn colour – I certainly did not choose them for the palatability of their fruits as judged by the local blackie population!
Eventually, it dawned on me that we never did get the benefit of the fruiting qualities of one of our trees – Sorbus commixta. It was planted for a number of features – it tends to make a tall narrow tree shape and has glossy green leaves that have a coppery tint when they first open. The leaves colour up well in the autumn. The berries are small and round, held in erect bunches and turn orange/red as they ripen, so I’m told. That’s my point, we never did enjoy the autumn splendour of the fruit colour, I swear that them dang black birds had a taster in their midst with the sole purpose of checking when the fruit was ready! This point is definitely reached by S. commixta before the berries are fully coloured. The invitations go out for the inaugural rowan party of the season. The noise is what draws attention in the first instance – wings thrashing among the leaves, it is not a fight between individuals, the bunches of fruit are not supported on strong twigs and that makes fruit picking on the wing for blackies, a tricky and noisy operation!
Becoming fascinated by this annual pattern, I had wondered at first if there was a preference for the fruits based on colour because white/pink/yellow seemed to remain untouched for a longer period with some hardly being touched at all. The colour may be implicated but the preference is surely based on taste. I could go along with that!
I convinced myself of this argument by cross-referencing to Cotoneaster. Some berries go quite quickly but how often do you see the semi-evergreen C. simonsi, very popular for hedging, still covered in brilliant orange/red berries in March/April.
By the way, Sorbus vilmorinii is on the menu this week. The berries are turning pink to white and disappearing like ‘snaw aff a dyke’ as I write.
Any constructive thoughts on the foregoing will be welcome.
Winter pruning
Last week I made a comment about delaying winter pruning until you can readily see the branch framework. As a PS, I should add that it is also easier to spot broken or crossing and rubbing branches, often an initial source of injury allowing disease to enter the tree. They should be removed with sharp secateurs or pruning saw. In that regard another thought occurs – the removal of substantial branches.
The first DON’T is that you must avoid damage to the tree. A large branch is best removed in sections and NOT sawn off flush with the trunk in one operation – that is likely to cause the bark to strip off down the trunk below the cut, simply because of the weight of the branch being removed. The correct way to achieve a successful outcome is to undercut the branch, say 20cm out from the trunk, cutting upwards to a quarter way through, then, moving to the top side of the branch about 25cm from the trunk, cut downwards. As the weight of the branch takes over, it will start to tear but the bottom cut will prevent the bark from stripping.
The second DON’T relates to the stub that is left. DO NOT attempt to cut it flush with the trunk. Close examination will show you that there is a slightly raised collar around the joint. The cut should be made on the outer edge of that collar. Reason? The collar accommodates a concentration of growth cells which were responsible in the first instance for stimulating branching. Remove the branch properly and they will stimulate healing.
To protect or not – that is the question.
Knowledgeable experts, far better trained than I, will insist that you don’t need to protect these major wounds, the plant is quite capable of healing itself. When I retort – well even if it is for cosmetic reasons only, it is advisable. Answer from the better informed – you might as well pick up a handful of soil and rub it on just to dull the scar. I know there is some scientific justification about a beneficial bacteria for that BUT, I still like to apply a wound-sealing paint immediately, so there!