November in the Garden

November is one of those months when gardening activity is largely dictated by the whims of the weather and, of all the months, November is perhaps the most variable. In a ‘normal’ year it is the final chance for those activities which depend on the last vestiges of warmth and active root growth—such as moving trees, shrubs, herbaceous perennials and the like. It is also the first chance to start those tasks which rely on the lack of plant growth and the onset of winter dormancy; pruning of roses, planting bare root stock, digging fallow soil.
Rose pruning is something which, as far as I am concerned, can wait a while longer as roses will only just be ‘slowing down’ and there is the whole winter still ahead of us. On tall specimens, especially those in exposed positions, it is a good idea to reduce the growth by about half to lessen the likelihood of ‘wind rock’ in autumnal gales. They can get their full prune towards the end of winter.
A mild November will allow the herbaceous perennials to gently collapse and die down with fitful flowering, from the stalwart late summer bloomers, continuing right up to the first frosts. A more severe month, with hard frosts, will finish off the borders practically overnight and then you may have to act swiftly to deal with dubiously hardy plants, such as dahlias and cannas, if you have them in your garden.
It’s always been traditional to wait until dahlia foliage is blackened by frost before lifting and storing the tubers in a frost-free place until next spring. The hassle of having to perform this operation, not to mention the need to find somewhere to store them (centrally heated houses are not conducive to successful overwintering), must have played a part in their fall from popularity in the first place. They are so ubiquitous these days that I wonder how many are kept from year to year, as they were in the past, and how many are simply purchased anew each spring and treated as disposable?
If left in situ they may survive in a mild winter but, especially in this wetter part of the country, they are apt to rot even if they survive the cold. The other problem with leaving them in garden soil is that they are bedevilled by those little black slugs which live under the soil surface; ‘Keeled Slugs’, I seem to remember from my old ‘Pest and Disease’ lectures! They gnaw away at the tubers in the damp soil and then nibble off every shoot just as they begin to grow again in the spring. Even a heavy mulching, which guards against a degree of frost, is no protection against soil borne pests and diseases.
Other tender plants should be under cover with some frost protection by now. There are many borderline hardy salvias to choose from which respond really well to being lifted and brought under cover until the spring. I have a really ancient specimen of ‘Amistad’ which suffers the indignity of being chopped back, dug up and re potted each autumn but which bounces back every spring to make an even bigger plant than the previous year. Just keeping them dry and under glass is enough for many of the woodier specimens but supplementary heating is advisable for any really tender ones.
If you can run power to your greenhouse then a simple electric greenhouse heater, with a ‘frost-guard’ setting, should protect your plants even when temperatures remain low for a prolonged period. Paraffin heaters are a bit more temperamental and they have the side effect of producing water vapour plus carbon dioxide which can be a problem in a confined space.
Back outside; now’s the time to plant tulips if you’ve been holding off, quite sensibly, to reduce the threat of ‘tulip fire’ (a nasty disease which is less prevalent in tulips planted late—after all the other spring flowering bulbs). I don’t find that many of the ‘fancy’ tulip varieties are reliably perennial. Planting them as deep as possible certainly helps, some of this may be due to the fact that shallow plantings are prone to predation by rodents, but if you want guaranteed displays then planting fresh, new, stock each year is recommended. Having said that, I often find that the old ‘Darwin’ type hybrids, generally in rather brash red and yellow hues, form permanent populations in many established gardens—whether you want them to or not.
Now that herbaceous plants are dying down and deciduous trees / shrubs are dropping their leaves, it is the evergreens which come into their own. Evergreen specimens are often referred to as the ‘bones’ of the garden, on which the summer ‘flesh’ is draped. As such they should not dominate but work best as structural elements or as solid backdrops.
Box edging, topiary balls and clipped yew hedges are standard, classic, examples of evergreens being used to anchor the more transient garden constituents. Without evergreens the garden would be a pretty desolate place from this month right up until growth starts again in the spring—still a long way off.
Another major, evergreen, component of the garden which acts as a calming foil, to the more flamboyant performers, is the lawn. Fallen leaves are best raked up whenever weather conditions allow, a leaf blower makes this task easier if you have lots of trees, or acres of lawn. If the leaves are not too thick or wet, and the grass is still growing, then using a lawnmower, assuming it has a collection box, to pick them up kills two birds with one stone. Leaves have less nitrogen in them to speed up decomposition, compared to green material, so composting them separately is advisable if you have the room to make dedicated ‘leaf-mould bins’. I tend to sprinkle a little ‘fish, blood and bone’ fertiliser onto each new layer in order to give the agents of decomposition a little helping hand—it can’t do any harm.