“These popular evergreen shrubs require very little pruning.”
Advice on pruning Camellias generally starts from the above standpoint, taken from George Brown’s “The Pruning of Trees, Shrubs and Conifers.” The implication is that very little pruning will ever be required and that you’ll probably get away with none at all.
Camellias however, are long lived plants, their lifespan on the scale of trees. Their growth rate is much slower than most trees though, so gardeners don’t give the same amount of thought to how big they will eventually get and what the consequences of that will be. It is a similar scenario to that of “dwarf” and slow growing conifers; massively popular in the 1960’s and 70’s, now nearly all gone because they outgrew their location and the only course of action was removal.
Perhaps the ideal is to let the plant get to the size required, or the maximum that its situation allows, then maintain it at that size. If you have a bush that is at that point it is possible to achieve that aim in one of two ways. You can clip it into a rounded (or square or whatever shape you want) dome and go on doing so on an annual basis. There is no denying that this works; there are several plants in gardens nearby that have been maintained in this way for years. They even flower pretty well.
Alternatively, and much more satisfactorily as far as I’m concerned, you can stand back and look for the branches that go beyond the outline you require and cut them back to a side shoot that is within the outline you require. That is likely to be best carried out after flowering in the spring and can be followed up in the autumn by removing any long extension growths that have been made in the second half of the summer and which have no flower buds for the following season on them.
In practice, most people don’t do this and the plant eventually outgrows its space. Paradoxically, it is the people with small gardens who are most likely to prune their plants. In a bigger garden plants need to be larger to be in scale with their surroundings but once the plant is too tall to be pruned from the ground it is more difficult and liable to be put off until unavoidable. Groups of Camellias grow into each other and become dark and bare stemmed beneath an evergreen “roof”. If they flower it is only the birds overhead that witness it.
Camellias are not averse to pruning in the way that most conifers are and when they have outgrown their situation there is a second option available which avoids removal. This is to prune them hard and to retrain them to a small sized bush that can then hopefully be maintained as described in the previous paragraph.
Camellias are hard to kill. I have seen large bushes, 8-10 feet tall, crushed under large falling trees such that all that is left is a jagged stump a few inches tall sticking out of the ground; then a year later they have produced shoots and are starting to come back. I have even dug plants out completely with a decent sized rootball only to come back a couple of years later to a ring of shoots growing up from the roots left beyond the rootball. So reducing a tree by half or two thirds is very unlikely to kill it.
In the vast majority of cases, if hard pruning is carried out in late winter, by the end of the following summer there will be a forest of new growth from just below the cut ends. Even if you can’t bear to cut a large bush in flower or just about to flower and delay pruning until the flowers are finished, you are likely to get almost the same response. It can be anywhere between six inches and 30 inches in my experience, with a whole raft of factors affecting the response. In general a strong healthy plant in good growing conditions will respond much better than a less favoured plant.
The upshot of this is that a strong plant will be back to the same size as it was before cutting but with much denser growth, in as little as five years. Since it may take as long to start flowering freely again that is clearly unsatisfactory. Plants in shade are worse in this regard, the shade causes more lanky growth and lack of sun reduces the number of shoots whose growth is cut short by a flower bud forming.
Pruning needs to be carried out with a picture in mind of what size you want the plant to grow back to. You need to anticipate the amount of regrowth you expect and cut back enough such that with that regrowth, the plant is still within the size desired. So if you want an eight foot bush and expect three feet of new growth after pruning, you need to cut to five feet.
Bob Flowerdew, talking about thinning plums on Gardeners Question Time said to thin them until you cry, then go back and thin them some more. It is much the same with camellias. If you have cut off 10 branches, why would you want 50 or 100 to regrow? They will be thin, crowding each other and drawing each other up in competition for light. They need to be thinned out to probably a maximum of three to each cut stem. They should also probably be shortened back, particularly if they are very long and thin. Thinning can be done any time, the sooner the better. Shortening back is perhaps best done in early September, late enough for regrowth not to occur that season and for flower buds to be visible, yet early enough for the reduction in foliage to reduce the plant’s vigour a little.
This pruning needs to start in the same year as the pruning took place, at least for the thinning. It then becomes a matter of keeping in mind the size of bush that you are trying for and cutting out the growth that goes beyond this. This removal should always be done in such a way that the cuts are hidden and a natural looking outline is retained. It may be that hard pruning will eventually need to be repeated but it is not very satisfactory as the only method of pruning used. If that becomes the case many of the shyer flowerers will not have started to flower freely after one cut before they need the next.
Two more things need to be borne in mind. The first is that you can’t maintain a bush at a particular size if you can’t reach where you need to cut. If the bush is taller than you are, reaching the middle of the top will be difficult. A ladder is not a good platform from which to lean three or four feet across the top of a camellia. A ladder on soft, sloping ground is even worse. Suitable long pruning tools may work but are expensive for only one or two bushes.
Secondly, a “typical” camellia produces an early flush of growth between March and June and a second flush between July and August. The second flush seems almost optional. In 2018’s very hot summer, almost none of the camellias at Mt Edgcumbe made a second flush at all. It is at the tips of the first flush that most flower buds form and if a second flush is produced it is at the expense of flowers. The second flush may be from many shoots on a bush or very few. It is usually the case that no flower buds are carried on the second flush growth which can be removed in whole or part from September onwards without detriment to the plant.
This plant of Debbie was cut back by around two thirds four years ago. The regrowth was thinned and shortened and in September 2018 I cut back all the extension growth made after mid summer. Plenty of flower buds had formed on the shorter, early season growths and these were all left on the bush. Now it is flowering with the flowers well displayed and not hidden amongst foliage and the bush is at least a foot shorter than it would have been if left unpruned.