I have had a short break from writing – partly because all I would be saying is, ooh look, another patch of brown earth that I have dug and some small brown seeds I have sown…Not that thrilling.
Fortunately Lou Nicholls, who blogs at loujnicholls.wordpress.com, has written a guest post for me. It’s the first ever guest post I’ve had and there will be a few more from other bloggers over the year. I’d love to know what you think.
Lou’s a marvellous gardener, with substantial experience from roles at both Garden Organic and Sissinghurst Castle. She also has a fantastic laugh, loves cake and drinks coffee like a chain-smoker. I’m lucky that she now lives just down the road from me and she’s agreed to tell me (gently) where I am going wrong with my fruit tree pruning. (Clue: everywhere!)
My head insisted on singing this to the tune of “How do you solve a problem like Maria” as I, once again, tackled the forest of shoots that are in a clients garden around her Lilac tree. I know Lilacs aren’t the only tree that have a habit of doing this but it did get me to thinking about the reasons why trees do this and what, if any, are permanent solutions to stopping them from doing so?
Lilacs are a lovely tree to have in the garden, relatively small, some are highly scented and with judicious pruning can produce a wealth of blooms. Brought from Turkey in the 15th century we now think of them as part of the quintessential English garden. Since the 1700’s they have been forced for the florists market to provide early flowers for the market but in recent years they seem to have disappeared somewhat off the gardening radar.
A couple of lovely varieties to grow are Syringa vulgaris ‘sensation’ an unusual bicoloured bloom of pink edged with white. ‘Congo’ is an old (1890’s) variety but reliable and highly scented, with distinctive flowers the colour of a good Merlot. ‘Madame Lemoine’ is a pure white and another reliable old variety. Bred by the Lemoine nursery in France it has stood the test of time.
Lilacs are also a good tree for chalky, well-drained soil. Once established they can withstand a summer drought which in these days of climate change is never a predictable thing!
I’ve always been told with suckers the best method of dealing with them is to rip them from the tree, this damages the growing point and prevents them from regrowing. If you cut them off neatly with secateurs it leaves the dormant buds intact and in a short while you’ll have 2 where there was only 1 previously. Like a many headed hydra this can quickly become an out of control beast! If caught early enough you can even just rub the buds out but what happens when the suckers come from the roots?
Some plants like Lilacs, Wisteria, cherries, roses & witch hazels are grown on root stocks. Whilst this has the advantage of controlling the plants vigour & health it can come with the down side of suckers. Once the rootstock has established shoots it will no longer aid the graft instead preferring to give its energy to its own leaf production, eventually leading to the demise of the scion.
This raises several questions
Why graft in the first place?
Once started how can it be stopped?
What is the cause & how can it be prevented?
1 is for the ease of the nursery producing (in the case of lilacs) it means they can produce plants at a time when the nursery would be quiet and far quicker than by other means of propagation.
2, simply put it can’t really, only controlled, which leads us neatly to…
3, this last question is probably the most pertinent as prevention is always better than cure!
So lets look at a bit of science as to why this happens….
The first and most obvious reason for a sucker is stress. Lets assume, in the case of lilacs & cherries in particular, the suckers are coming from the roots. This is a type of vegetative propagation, the tree is cloning itself through basal shoots from adventitious buds on the roots. Plants are so clever in this respect! If we cut off an arm we couldn’t possibly expect to grow a new us from it but plants can send out new versions of themselves from practically any body part. Each part of a plant, including the roots has the capability to clone itself.
Plants do this in a response to a few things that cause stress, over enthusiastic pruning is one cause or injury to the root system can be another.
In the case of over enthusiastic pruning the plant has developed a root system directly in proportion to the canopy, usually 3 times the canopy’s size. When the canopy is reduced dramatically the plant thinks it’s under attack and will do its utmost to propagate itself.
The more tricky one to deal with in a garden situation is root damage, this can be caused by digging near a tree in a border or even by mowing the grass. For trees that have a shallow root system their roots can often be damaged by close mowing and once this stress response is triggered it can often be almost impossible to prevent a reccurrence of shoots. Better to prevent it than cure it. This of course doesn’t help us once it’s already happened though.
The second reason can be from a failing graft union. This can occur for many reasons
Anatomical mismatch – a failure to line up the rootstock and scion in the initial graft. This usually becomes apparent very quickly.
Damage to the graft union – this can occur when hoeing around the base of the tree or in the case of grass land strimming too close to the base and “ringbarking” (removing the bark from around the base of the tree causing the flow of sap to the scion to be interrupted)
Fungal/bacterial infection – the graft is a weak spot and is always susceptible to infection.
How can you give your tree the best start in life to avoid these things?
Selecting a plant that looks healthy, vigorous and has a clean healthy graft union is obviously a good start, if you can buy from a reputable nursery they will be happy to explain what to look for. That’s the great thing about buying from nurseries that produce their own stock. The staff actually understand plants and are enthusiastic to share their knowledge with you.
The next step is planting, in the case of lilacs their rootstock graft (if they have one) is often privet ligustrum ovalifolium. Now the RHS will tell you to plant with the graft joint above soil level. This will prevent suckering of the lilac itself but it can also have the disadvantage of preventing the scion to from forming its own roots and if the graft fails, which it likely will over time, the plant is lost. However advice on lilacs from the Arnoldia arboretum and from Chris Lane(owner of the Witch Hazel nursery in Kent who has a wealth of knowledge and who’s opinion I greatly respect) differs, they suggest that the scion be allowed to develop its own rootstock by initially planting level or slightly deeper and then mulching for the first year. Their observations on lilac grafted on various rootstocks go as far as to suggest that the graft is doomed to failure after 4 – 5 years and encouraging the scion to develop its own roots is necessary. If you’d like to find out more have a look at this paper. I’m inclined to go with their advice myself despite the risk of developing suckers in later years but as with all cases of differing advice the choice is yours of course which you listen to.
Back to the problem of suckers though!
Lets assume you’ve given the plant the best start in life you can but despite your best efforts it’s started developing suckers or that you’ve inherited a plant that is already creating a mini forest of clones around its base. What then?
Dont ever be tempted to spray these suckers with weedkiller! Their “blood supply” is the same one that nourishes your beloved tree and will kill that too… you’d be surprised how many times people have done this and then wondered why the tree has died!
The best way as already mentioned is to tear/rip the sucker off as close to the root or stem as possible. If this just isn’t possible I find a sharp spade does the trick. The key is always persistence, once a plant starts to sucker it will continue. Your job is to make sure the plant stays as happy and healthy as possible. In autumn feed with well-rotted manure mulched around the base. In dry periods, like we’ve been experiencing in the last month or so even established trees will appreciate a bit of water on their roots and continue to remove the suckers as and when they appear and your lilac trees will continue to have happy healthy lives!
For six years I lived on the doorstep of Great Dixter and like a lot of gardens in the area it has a theme of high hedges and garden rooms so synonymous of Lutyans arts & crafts style work. Great Dixter though has an added twist of having had Christopher Lloyd own it and put his stamp on it.
Many finer writers than myself though have beaten this subject to death so I don’t need to gush and enthuse on the subject of Dixter and its design, suffice to say its worth a visit and has changed subtly since the death of Christopher. Which isn’t a negative thing rather a natural thing as gardens are living creations and to try to keep them static is an odd concept.
One thing that always strikes me though when I visit Dixter is its size, I’m always shocked by how small it feels. When you think of famous gardens you often think of rolling acres, at least I do, but Dixter is an oddity in so many ways. The gardens never seem to take long to see in their entirety, although there are areas where you can linger quite happily. The house itself, despite its appearance of having stood on that spot forever was actually only placed there last century. I say placed, not built as Lutyens and Nathaniel Lloyd (Christopher’s father) actually took the main part of the house from a village called Benenden nearby and reconstructed it. Melding it into the original structure that was already there known simply as Dixter. As a visitor you would never know this though as it was done so successfully it has the appearance of a house that has grown organically for centuries.
The gardens are being added to continually in the way Christopher did when he was alive. Fergus’s commitment to Dixter and its ethos of teaching being something special to witness.
The plant fairs though, especially the Spring one are a great opportunity to get out and see small independent nurseries offering beautiful plants at very reasonable prices. I admit its become something of a spring time pilgrimage for me. Even if it now takes me a couple of hours to get to it instead of a couple of minutes! They also do a great thing throughout the weekend where Nurseries give talks throughout the day. Often entertaining, enthusiastic speakers with a wealth of knowledge on their chosen subjects, which if you’re a plant nut like me is well worthwhile!
For me there were 2 that particularly stood out the first being Barnhaven, a fabulous nursery dedicated to one of my greatest loves Primulas.
I wrote quite extensively about auriculas on my old blog so if you’re interested have a quick look here…
Barnhaven has recently supplied Sissinghursts garden with a large amount of old variety primulas in their efforts to repopulate the garden with varieties which were there in Vita’s time. Gardens often lose specific plants, sometimes even their own bred varieties. This I’ll mention again in a moment.
Sometimes a gardener will endeavour to reverse the changes time makes to a garden and small independent nurseries are critical to retaining the genetic stock. Barnhaven is not only responsible for maintaining collections of amazing old varieties and making them available to the public, such as “jack in the green” a very old variety with a charming corolla of leaves which cup the flowers to breeding new introductions and bringing back styles such as the stripey and double Auriculas.
The second was a talk from Steven Edney, Head Gardener at Salutations, another gorgeous Lutyens garden. The gardens are a tribute to his hardworking team and unceasing enthusiasm. Having suffered a massive flood in 2013, only 5 years after the gardens were officially reopened after years of neglect, they are once more in beautiful condition and this year is their 10th Anniversary!
Steven touched on the subject of “lost plants” having fortuitously been offered a cutting after the floods of Hebe “Salutation” originally bred at the garden in the 1970’s. His nursery on site has propagated it and it is now available to the general public, another example of how important some plants can be in context!
He is full of little gems of information too, he told us about plectranthus fruticosus an important plant to Edwardian gardeners as it would be used as a reliable indicator plant for frost. When nighttime temperatures drop below 5 degrees it develops a bronzy colour to the leaves and this would be a sign to the gardeners to lift their tender plants like Dahlias into the glasshouses.
I had to take a second look at this amazing Asphodeline liburnica and was tempted by some of the seeds he had for sale, grown & collected in the gardens!
Another fabulous nursery is Pineview plants run by the lovely Colin and Cindy Moat who always have time to help you out choosing the right plant for the right place. I fell totally in love with his Epimediums and after going away and coming back THREE times finally settled for this gorgeous one called aptly “Ruby beauty”
Whilst there I mentioned my mystery Epimedium I’d been given which hadn’t as yet flowered… which of course by the time I got home that evening had… So here it is and I’ll be asking Colin if he can help me identify it!
There of course are many fine other independent nurseries at the plant fair which are well worth your time and if you’re not aware of one’s in your local area here’s a list that although not comprehensive is getting close and is constantly updated