Obviously, autumn is the season when we expect deciduous trees and shrubs to shed their leaves and November is the month when this activity is largely completed. This year has been a little different because many trees and shrubs lost their leaves early as a response to summer drought. Since then, I have noticed a few species, Hamamellis seems particularly affected, produced a small flush of new leaves once the rain returned. My worry is that these leaves were from buds which should have burst next spring so, assuming these are shed before winter, I’m not quite sure what will happen next year?
I also fear that all the stress induced by the long, hot, dry summer will result in a lot of die-back in trees and shrubs, especially those entering their twilight years, which will result in increased limb loss and trees blowing over as soon as we get storms and high winds. I think it would be a wise precaution to go out and check any large trees and shrubs that you may have, now that leaf-fall has exposed their woody structure, to see whether they are showing signs of disease, death or have begun to lean in a dangerous way. If you spot a dangerous tree near a road, or in a public place, then report it to the Council before it can cause a problem. Even trees protected by a ‘Tree Preservation Order’ can be felled if it is posing a danger due to advanced disease or imminent death.
In a ‘normal’ year November 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.
If you are one of the growing number of gardeners that has been seduced by exotic social media images of showy dahlias, once horribly out of fashion, then you’ll probably want to save any that you have planted out in the garden. It was traditional to wait until dahlia foliage was blackened by frost, before lifting and storing the tubers, but I think they’ll need lifting by now even if they’ve not been frosted. Store the cleaned-up tubers, minus any attached soil or foliage, somewhere cold but frost-free; when I was a kid our family dahlia tubers lived in the garage over winter!
As a note of difference; if you have cannas in your garden, they lend a wonderfully exotic feel to a border, they should be dug out, to be kept frost-free over winter but, unlike dahlias, I find they cope better if they are not allowed to completely dry out, once their foliage has been chopped down, but kept potted in, just barely, damp compost. They need to be kept cold enough to stay dormant but, like dahlia tubers, somewhere frost-free. This is a tricky balancing act, especially in modern, centrally heated, homes but a greenhouse with frost protection or an unheated, glazed, porch would suffice.
Other tender plants should be under cover with some frost protection by now. 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; carry on with planting spring flowering bulbs. It was always recommended to wait until November to plant tulip bulbs as a means of minimising the threat of ‘Tulip Fire’ (a spore borne disease) but this seems to have been dialled down a bit these days. The ‘RHS’ advice is still to plant them now, with all other spring flowering bulbs “preferably planted by the end of September”. I don’t think I ever get all my bulbs in by then and, in fact, many spring bulbs don’t even get delivered by September. Also, I often get seduced by those ‘last chance’ bulb offers which obligate late planting and, touch wood, so far I’ve got away with it. Basically; get on with bulb planting now!
Hopefully it won’t be so cold this month that all other gardening activities have to stop. Keep cutting grass, on a higher setting, if it’s still growing. Rake up leaves where they threaten to swamp lawns or borders. Finish cutting evergreen hedges and topiary when it’s dry and warm enough. Make plans for those tasks which need ‘complete dormancy’ as winter is just around the corner.
