I have a few shrubs that have gotten way bigger than I ever expected. One is a hazelnut that is about 13' high and just as wide. It is really lovely though it doesn't bear since it doesn't have a mate. However, it is rather too big for the space I have. And a Sambucus canadensis is also about 13' high and I don't want it to get any taller. I am feeling that I would like to take some control here if somewhat belatedly so that others in the garden have more space. What might be the best time to prune them back? Ideally I would be delighted if the hazelnut, for example, were about two-thirds that size. The width is more problematic than the height. Is it possible to scale it down? In a similar vein, I am very much wanting a lilac. (Truly, I wish I had a much larger garden.) I am considering Syringa vulgaris "Adelaide Dunbar". I read that it grows to 10-12'. Is it possible to keep it at about 8' and still in good form and health? I would be very grateful for some advice on this issue. April
Well... I can tell you that you can hack away at that hazelnut as hard as you want and it will do just fine. It will sucker like crazy, so be warned. As for the rest I don't know for sure, but so long as it's don't at the right time of year my guess it that you can prune just about anything to the size you want. Eg: people turn 12" trees into 2" bonsai all the time. The only trick is that it be at the right time of year, and in stages if the species requires it. Just some thoughts, Michael
I have a sambucus nigra variety (two actually - variegata and guincho purple) that I hack away at all summer long as it is next to the front steps and would bar us from the house if we let it grow. It doesn't sucker nor does it complain in any other noticeable way. With most pruning the trick is to enable blooming or bearing, as in nuts, and so you do it right after bloom. That would be the issue with lilac - obviously you want this to bloom as it has no other virtues. You need to study what wood things bloom on (most spring bloomers do so on last year's wood, summer bloomers on new growth, etc) and prune accordingly.
Thank you Michael and Karin. Yes, it makes sense to plan the time of pruning in relation to the flowering or fruit bearing time. With the elder, I'll think in terms of after the birds have eaten the berries. One thing about pruning that puzzles me, is that sometimes one prunes to encourage bushiness, and sometimes to reduce the size. If one is wanting to promote bushiness, it would seem to make sense to prune in early spring when the plant is in a growth period. Of course, that would clash with the other principle if it flowers on last year's wood. And if one were simply wanting to reduce the size, one might prune when it is dormant. Is this thinking correct? Of course, then there is the principle of expediency, e.g. yesterday when I cut back the viburnum that is in full flower to give the young clematis behind it more light. : ) I very much appreciate this opportunity to learn more about pruning. My tendency has been to be laissez-faire until I suddenly recognize that others are getting cramped and I need to take action. April
Hi April--I'm not great at pruning, but I would venture one opinion about trying to limit size. In general, pruning in the summer will reduce size much better than dormant pruning...cutting off top growth in winter will simply encourage vigorous growth next spring from the now unbalanced root system, which will try to get the top back in sync with the roots. Summer pruning will weaken the root system somewhat, reducing photosynthesis as well as removing some food reserves in the pruned off material. You will still try to work in the flowering/fruiting considerations, often it's impossible to satisfy everything and you just have to chop away when you have time and energy! Many of us fight the same battle, and realize eventually that it is a hopeless fight because plants never stop growing bigger, except when they die! We just try to buy ourselves some good years until reality forces us to take more drastic action...
Multiple pruning books available from bookstores and libraries, look up the recommended approaches to each particular kind of shrub in these.
