The Garden in November 2024 - ‘Beating the Weeds!’
Even I have to admit that November is not the most inspiring of months in the garden with its shortening days and often wet and windy weather, the trees shedding their leaves and colours in the beds and borders beginning to fade. However, there is still interest to be found even at this time of year from evergreen and variegated shrubs, the structure and form of bare trees, hedges and other shapely plants as well as the colours from stems and berries and those plants which choose to flower towards the end of the year.
Not surprisingly most of these plants have featured in past November blogs which started in 2020 with a look around our own garden in West Wales, especially at the trees providing late autumn interest such as cherries, the Katsura Tree (Cercidiphyllum japonicum), Cornus, Field Maple, Acer griseum and the native Silver Birch (Betula pendula) all of which were displaying their rich autumn tones as well as some shrubs and perennials which were holding on to some colourful leaves and, albeit a few, fading flowers. The second part of this blog went onto to look at a whole range of plants, mainly shrubs but also a few climbers and some early flowering plants such as Helleborus niger and the earliest of the spring bulbs which can offer interest in any garden throughout the coming winter months in terms of flowers, of course, but also coloured stems or bark, berries and interesting shapes from both evergreen and deciduous specimens. In the final section the 2020 blog looked at some jobs for November when the weather permits such as collecting up leaves, cleaning the greenhouse, pots, trays and tools as well as the ‘dig or not to dig’ question. The 2021 blog came from the gardens at Aberglasney where, even in November, there is always interest and beauty to be found. In 2022 I wrote in some depth about one of my favourite plant genera for almost any month- the wonderful Viburnum. This was followed by some recommendations from Lucy, the Plant Area manager at the Old Railway Line, for five excellent plants for autumn interest- Skimmia, Hamamelis, Callicarpa, Euonymus and Cercis. Finally last year I was thinking about the new gardening year to come and took a look at some reliable plants for the more difficult spots in our gardens such as hot, dry and sunny sites, shady areas both dry and damp and areas exposed to strong winds. All of these can be found on the Old Railway Line website under ‘news’, ‘show tags’ and ‘monthly guides’, as can all the blogs that I have written since 2020, some under the title of ‘gardening tips’.
As for my ‘plants that I wouldn’t want to be without’ in November, it has to be said that there are not too many ‘stand out’ plants for this month. However, there is still plenty to admire in the garden, partly from the late flowering plants which will continue until the first hard frosts, the autumn leaves on shrubs, trees and climbers and the real late autumn specialists such as the Kaffir Lily, Schizostylus, and the exotic Nerine. In our own garden Teresa and I will continue to enjoy many of the flowering plants which I have highlighted over the last few months such as Hydrangea, Sedum, Helianthus ‘Lemon Queen’, Rudbeckia, Aster and Leycestaria formosa . We even have a few roses on our ‘Malvern Hills’ rambler and some very late flowers on our large Buddleja. The two cherry trees are also colouring up nicely as I write- ‘The Bride’ with its small, serrated leaves turning orange and yellow and the ‘Royal Burgundy’ with its normally purple-red leaves becoming a striking, bright red. Our maples are also performing well, some yellow others various shades of red and orange. One other plant which I feel I must mention, rather surprisingly for a November blog, is the summer bedding plant Begonia sempervirens, the small-flowered, fibrous rooted Begonia. We bought a tray of 20 plants back in May for not a lot of money which was enough for two small troughs and two other pots. They were planted out in late May after the threat from frost was over (Begonias are particularly susceptible to frost!) and they have flowered continually from June into the late part of October as I write this and are still looking at their best which they will do right up to the first hard frost when alas they will go black and mushy overnight! They are extremely easy to grow- ours have just had some slow-release fertiliser at planting time, have been watered when necessary, have not needed dead heading as their spent flowers drop off naturally and have not been damaged by any diseases or pests, even the dreaded slugs and snails which have been a real problem this year for us all.
One of our Acers and the two troughs of Begonia sempervirens still going strong in late October!
You can’t keep a good Hydrangea down!
Good colour on the cherry, maples and Leycestaria formosa
For the remainder of this blog I am going to take a look at a problem that all gardeners face constantly and that is how to get on top of ‘weeds’. As it is often said there is actually no such thing as a weed, they are simply plants that are growing where they are not wanted by the gardener, or farmer, and quite often one gardener’s weed is another gardener’s beautiful plant (one of our neighbours just loves to have Rose Bay Willow Herb in her garden!). For this reason, perhaps they are better referred to as ‘unwanted plants’. They are unwanted for a variety of reasons- the gardener simply doesn’t like the plant, the plant seeds or spreads by another means rather more than the gardener requires, the plant sprawls over and spoils more attractive plants or even more serious the plant takes over the whole area and makes it difficult for other plants even to just to survive there. Whatever the reason for considering a plant or plants to be unwelcome, there are three basic options for controlling or removing them- mechanical removal methods, mulching beds and borders to try to prevent or at least reduce ‘weed’ growth and chemical methods. I have chosen to write about this now because autumn is a very good time to try to clear our gardens of as many ‘weeds’ as we can before they have a chance to set any late seed or to spend the winter slowly spreading, almost unnoticed as we are out in our gardens less often than at other times. As those of you who follow my blogs or have attended any of my Saturday morning talks at the Old Railway Line will know I am a great believer in reducing our use of chemicals of any kind both in our gardens and the wider environment because of their negative impact on biodiversity, so I propose to concentrate on the first two methods but will end with a section on the very selective use of chemicals if all else fails.
The main mechanical or physical methods of ‘weed’ control involve the use of forks of any size, hoes of any type and the simplest and possibly best gardening tool at our disposal- fingers and thumbs! I’m sure that most gardeners have heard the old saying- ‘one year’s seed is seven years of weeds’ or as some people say it ‘one year’s weed is seven years of seeds’, which both amount to the same thing- deal with the weeds when you see them or you will have more unwanted plants to deal with in the future. There is another old saying which is perhaps less well known- ‘don’t let weeds see a Sunday’, in other words whatever methods of weed removal you use you will need to use them often to prevent the one weed becoming many. The gardeners’ friend, the hoe, is a great tool for dealing with annual weeds when aimed carefully, of course, at the right plants which on dry days can be simply chopped off by shallow hoeing before they get a chance to produce seed and either left on the ground to shrivel or collected for the compost heap. It is always best to avoid deep hoeing as this can bring more seeds to the surface to germinate. For just the odd weed here and there a hand fork or just the fingers and thumbs will do the job nicely. Another effective method to control annual weeds such as chickweed and groundsel is the use of a flame gun as long as a strong flame can be generated which simply burns off the top growth of the plant. Unfortunately, none of these methods are very effective on plants which are perennial and have a larger root system such as dandelion, oxalis, nettle, thistle, couch grass, bindweed and ground elder- how many of you have just shuddered just in reading the list? As you know just removing the top growth might set them back a little but it won’t kill or eradicate them unless it is done systematically over a long period. This is where the fork comes into its own so that the top growth including any seeds and the whole of the root can be removed. It is important to get the whole of the root as even small pieces can survive and grow back again. For this reason, in my view it is better to use a fork rather than a spade or a rotovator which are much more likely to chop the roots and leave small pieces in the soil. This, of course, is very easy to write about but much more difficult to do. It can be a long, painstaking and physically challenging operation but it is necessary to get on top of perennial, often referred to as pernicious, ‘weeds’ and just has to be done if you are committed to not using chemicals. There are some other mechanical methods of ‘weed’ control for particular areas such as the use of boiling water- be careful!- to kill the top growth of annual plants in block or slab paved areas and also within greenhouses. I prefer, though, the much safer method of using a long-handled, wire brush in paved areas which has the added benefit of removing soil and other detritus from the joints that, if left, just encourages future plant growth. ‘Weeds’ in the lawn are particularly difficult to deal with if the gardener wants to avoid the use of chemical weed killers. Scarifying and regular mowing to remove the top growth of the ‘weeds’ will help to, at least, weaken most broad leaf plants and allow the grass to dominate but it does little to prevent the growth of plants such as dandelion which have long tap roots. I try to keep on top of these with the use of a long knife to lift the whole plant if possible or at least to cut off most of the root. For most lawns it is probably best to accept that there will always be some other plants amongst the grass and to just live with it. In areas away from the house, of course, it is always possible to just mow paths through the grassy areas leaving the ‘weeds’ which are essentially wild flowers to do their own thing in the areas between and in doing so allow them to bring their own beauty and their many benefits to wild life.
The second method of ‘weed’ control is the mulching the soil with some form of surface layer and is an excellent preventative method, best used I think when the hard work of cleaning up the soil has already been done. Basically, the idea is to cover the soil surface with a deep enough layer so that any ‘weed’ seeds are buried too deeply to successfully germinate. Materials such as spent mushroom compost (but not for acid loving plants as it contains lime), well-rotted manure, home-made garden compost, purchased soil conditioners and wood or bark chippings are all suitable which, of course, have all the additional benefits of improving soil moisture conservation, adding to soil fertility, supporting vital soil micro-organisms as well as looking attractive. For areas of permanent planting the surface covering can be a fabric or plastic membrane which allows water and air through but helps prevent or at least reduce weed growth by acting as a physical barrier to plants trying to root from above or growing through from beneath. Planting is done by cutting a cross-shaped slit in the material, folding back the flaps during planting and then replacing them around the base of the plant. Following planting the membrane can be covered with a thin layer of organic mulch such as bark, gravel or pea shingle. This method is particularly good at conserving water in the soil and greatly reduces the need for watering after the initial watering in at planting time. A similar technique can also be used as a temporary method of clearing an area of pernicious ‘weeds’ when the covering material can be old carpet or black plastic sheeting both of which will starve any unwanted plants of light and to some extent water. Usually after 6 months of this treatment the covering can be removed and the area forked over to hopefully remove the last traces of the plants in question.
This brings me onto the use of chemicals herbicides in the garden which I accept might have to be resorted to in some circumstances as I do myself when all else has failed. For example, I do use a granular lawn treatment each spring and autumn which contain not only fertilisers but also chemicals to control ‘weeds’ and moss but I apply these carefully and on calm days to avoid any drift onto neighbouring beds and borders and especially the pond. I will also from time to time use a herbicide based on glyphosate which will not persist in the soil and will kill only what it falls on. For example, I use it on our gravel drive and in the gaps between paving slabs for deep-rooted plants such as dandelion but I don’t use it in the beds and borders or the vegetable bed to avoid the chance of any drift onto neighbouring ‘wanted’ plants. I also make sure that I spray close to the ground and on calm days to reduce the chance of spray drift. There is another way of doing this with the use of glyphosate in the form of a gel which is simply brushed onto the leaves of unwanted plants and this is obviously a good way of dealing with the odd ‘weed’ which pops up in beds and borders close to ‘desirable’ plants. One final point on this subject it is worth saying that for glyphosate weedkillers to be effective the ‘weeds’ need to be actively growing so that the chemical is moved internally to all parts of the plant and the spray needs around 6 hours without rain to be absorbed fully by the leaves.
That’s all for this month but I will return in December for the final blog of the year when amongst other things I will deal with the topic of winter pruning and will take a look back at this year and all the topics I have covered and where to find the in the blog archives for future reference. Until then get out into the garden when you can and don’t forget that spring is just around the corner!
Keith.