Wednesday 29 January 2020

Plants that become weeds

Who wants a twenty acre wood of cardiocrinum?

Garden plants that take over

Horse radish is very difficult to eliminate
The press reported when Jeremy Corbyn gave Tom Watson horseradish plants from his allotment that it was a show of good will.
It was a poisoned chalice.

One of my achievements when I took on the overgrown Bolton Percy churchyard almost fifty years ago was to eliminate this weed. It had roots two spits down and roots as thick as my arm. It took two years of glyphosate spraying to remove it.
If conventional perennial weeds are allowed to stay undisturbed in the ground for a very long time they too become so strong that they are much harder to eliminate than the text books might claim and need extra applications of weedkiller. (Not always - a strong stand of undisturbed couch grass will succumb to glyphosate in one go  and as I previously described I eliminated many year’s of established and crucially undisturbed, convolvulus very easily in Steven’s garden).

Some plants have the capacity to build up their strength for year upon year if left alone. Have you ever tried to dig out a ten year old hosta? 

Left for decades  some plants will become  monsters. Witness Japanese knotweed originally planted in Victorian gardens and how now ten foot high plants rampage through a landscape. As a new individual plant it is a pussy cat and easy to control.

I do not want my legacy to be Equisetum hyemale taking over Bolton Percy Cemetery (I have already eliminated it)

Indeed I would go so far as to suggest some potentially problem plants are difficult to get started. Gardener have often told me how their lily of the valley just won’t grow. Others struggle to eliminate strong stands or slow its spread.
Some plants year upon year build up huge resources. Beware.

Books warn not to plant aggressive houttuynia. This one took several years to achieve 
It is not my intention to frighten you today. Quite the opposite. For myself I love plants that are tough and can take care of themselves. If they spread horizontally and fill up large spaces that suits me fine. I relish the spread of such as alstromerias and Autumn anemones.
This Autumn anemone makes seven feet on Bolton  Percy heavy soil. It struggles to three foot on my own sandy soil
Some folk fear alstroemeria because they 'run'
There are perhaps two main characteristics of potential rogue plants They spread horizontally and/or make deep root systems or other resistant perennial structures. 
Bluebells such as these would be very difficult to eliminate should you wish to do so 
I will almost ignore today those plants that take over by self seeding. 
Perhaps just a word about bluebells. From seed they are slow to come up to flowering and even from strong bulbs they take a while to make up to a decent display but once established are really thugs. Beautiful thugs and in Worsbrough cemetery cover huge areas.

Perfect storms
There is more to it when certain plants take over than having planted the wrong subjects or long years of inaction. A major factor is whether the plant loves your conditions. Things such as soil type and fertility, drainage and light conditions. Just as a good gardener goes out of his way to plant in the right place for maximum success, for some of the thugs you can have too much of a good thing!

Monty says never plant skunk cabbage, it might take over. Here in a bog at Bodnant perhaps after a hundred years they are somewhat over grown but look quite superb
I moved from a heavier clay soil to my Seaton Ross sand. I was overjoyed to grow plants I could not before.
It was a great disappointment to find for others I could not. My beloved Aster ‘Violet Queen’ now needs all my skills to maintain it. The Japanese anemones although still lovely only make half the height than in Bolton Percy. Achilleas, hepaticas, bulbous iris and echinacea just fade away. Phlox do well for me but take years longer to establish strong clumps. (On the other hand Phlox subulata creeps freely and is a sheer delight).

Several thugs that the garden gurus tell us not to touch with a bargepole are for me shy maidens and difficult to grow. I delight that my Houtonya spreads at all. I bought expensive skunk cabbage and after twenty years I rejoice that it is big enough to be noticed.

Horror story follows about this shy plant that transforms into a monster
An extreme case of a ‘delicate’ plant ‘going native’ is the lovely poppy-like herbaceous perennial Romneya coulteri (shades of Mrs Coulter in Phillip Pullman’s wonderful ‘Dark materials’). I just cannot grow it at all. Not in any of my very different gardens and I have tried several times.

Peter Williams received an appeal from Glasgow. I think about a well drained sandy light soil - I never saw it but clearly a dead ringer for Romneya’s native habitat. The lady owned  an old sandstone property which was being ravaged as the roots ate up the foundations. Every story you have read about Japanese Knotweed was mirrored and exceeded here. I am not sure whether my own advice helped the dear lady. I wish now I had taken more interest, helped her more  and got some pictures
Peter Williams tells me he does manage to grow Romneya. In the past with great difficulty. It is now making very strong suckers. Some garden threats lie there as sleepers.

Woody wanderers
It goes without saying that self sown and inappropriately planted trees create dense shade and damage foundations. Not my subject today.
Many climbers are woody and some can be a menace. 
I have written before how global deforestation often gives aggressive climbers and sprawlers a foot hold. In the UK too some become monsters.
Most of us have witnessed how aged Russian vines are a nightmare to remove and it might take days to cut away from old buildings.
More innocuous genera do have their monsters. Clematis armandii and passiflora caerulea  are both tender plants that in the North can be difficult to grow. Given space and time and absence of pruning in a warmer climate they are a real menace.   The ever popular Clematis montana  has its moments too.
Give wisteria several decades and your parkland will become a jungle.

Always think twice about planting bamboos There are some none-creeping kinds but for the others beware.

Peter Williams hard prunes his Kiftsgate every year. If he did not do so he would have a monster on his hands
When I had my own clients my dear friend Jackie Barber grew that rampaging rose, ‘Kiftsgate’. It is super vigorous, lovely, very thorny and will swamp even quite vigorous trees. I dreaded the uncomfortable prickly day that her single plant would take me to prune each year.

I have just returned from Madeira where it strangled one hundred feet cliffs - sorry forgot camera!
There are herbaceous stranglers too. For most of us ipomea is a delicate annual. In Vico Equense (my son lives there) it is truly  perennial and over the cliffs and adjacent gardens creates huge tracts of blue. Think of our own bindweed. Naughty but nice.

Bits and bats and bog plants
Give it five minutes and hippurus will take over a huge lake. (Carefully directed glyphosate easily zaps it in your small pond at home)
This section has a watery theme. Bog areas and ponds are particularly vulnerable to rogue plants going native. Plants that have evolved to like wet conditions just keep on growing in sunshine and on really good sites never lack for water and have little competition from regular plants.

Leucanthemum, the shasta day
We always take our umbrella when we go to see Rowena and Harry in very wet Preston. I mentioned this post to Rowena and she confided in her problem with leucanthemum, the shasta daisy with which she has a love/hate relationship. Their garden is on 30 foot deep heavy clay, there is heavy rainfall and water springs appear in awkward places. Many of the fine plants she puts in die. Her shasta daisies are lovely. (She has a beautiful white border and guess what is the dominant plant). It spreads everywhere  and even in relatively dry weather her clay soil generously sustains it. It is starting to penetrate into the mortar of her brick wall. For the moment the house is ok.
Dammit it has died out on me. To be fair to this vigorous plant I have only tried the poncey double and fancy-petal varieties. 

Back to  bog plants some of which are are prominent in lists of alien plants illegal to grow and some have prohibitions on selling and planting. 
Over the top but some aquatics in water courses are a serious menace.

My gunnera loves its boggy patch. I wonder what it would do if left untouched for fifty years
The answer to the above question is that its spread would cease when it met drier soil - or strong plant competition (I might be able in a few months be able to tell you what complete submersion for six months does to it - my garden is still half under water - drains now in place)

One answer to over aggressive plants is to let them fight it out with each other
 Aristocratic weeds
Peter and I attended a lecture that pictured a neglected ten acre site completely taken over by cardiocrinum lily. It really hurts your wallet to buy one. They take perhaps eight years from seed to flower and set seed before each plant dies. Absolutely magnificent but a nightmare to tackle. Its what you get after fifty years of leaving alone. They retail at twelve quid a  throw.
I suppose when your lake is taken over by water lily you might describe that too as an aristocratic weed.

I wonder if you have any other candidates? 

More about the Romneya nightmare
Peter Williams has furnished me with some of the details of his anguished correspondence. I pick out some of the details from the emails he shared

….the builders are immediately moving in here, as the house has been invaded by a nasty, vigorous plant from the garden which is growing between the plasterboard and the masonry in the dining part of the kitchen. 8ft high and 3 ft wide. Has 
entered from garden under the bottom layer of our 6 layers of flooring insulation…… 
….Romneya coulteri, an American poppy, but not just any old poppy. A poppy on steroids. As well as having to have the kitchen dug up (and we don't know how far it has spread in the house), we then also  have had the patio slabs lifted to find out where it has entered the house, and then most of the large border excavated to eradicate it between the patio and the far end of the garden… 

….We hope the inside work will be finished by Christmas, but don't yet know if the outside work will start immediately or will wait until the spring. It has also spread into our neighbour's garden, who, like us, have been cultivating it assiduously as it is a very beautiful, large showy plant with lovely huge white flowers in late summer. No sign of it in their house, though…..

…… Not covered by insurance, as this has been gradual and not an "event". It was planted by the previous owner of our house, who was an avid gardener. It is very difficult to get it established in UK, as it likes desert conditions, but she managed it! …..

What a nightmare

Sunday 12 January 2020

What makes a gardener?

What greater pleasure than to breed a new plant
I don’t mean what makes a successful gardener, I mean what makes many people just want to grow plants. Some of us are so besotted we think of nothing else. I write about both gardeners at home and those who dedicate their whole professional lives to it
Is there a ‘green gene’?
I wonder how much our love of growing is genetic. Clearly some of us will have characteristics that predispose us to it. But is there some arrow perhaps shot when some of our hunter- gatherer ancestors started to sow and plant plants?
Involved in horticultural education I would interview young people whose sole desire would to be gardener. 
On the other hand mature students would declare their long desire to garden even on their retirement from another profession. 
Alan Warwick  - equally proud of his spuds

My friend Alan Warwick - I wrote about the Chelsea apple tree he bred and his insightful theory about how water gets to the top of a large tree -  was a very senior ICI executive who on his retirement enrolled on my one year craft gardening course, bought a small nursery and now thirty years later at ninety one gardens all day.
No dig gardener - digging? (No just lifting)
In my own case I got the bug at the age of 14. Up to that time weeding my parent’s garden was an unwelcome chore and not a joy. We moved to a new house with an overgrown garden and as I have written before, my parents (to my juvenile mind) did not have a clue or inclination what to do. I took it upon myself to restore the  garden. It was digging out couch grass and the smell of the soil that turned my green gene on.
The pleasures of gardening
I thought it would be easy write about the joy of gardening. Not so. For every gardener it is something different. For every gardener there is a different garden
Gardening is a spectrum running from pure hatred to a reason for living. It runs from intense physical activity to easy gentle reflection. It contrasts precise manipulative garden maintenance to communion with nature.
Best give a few examples

* I know a lady whose idea of pure heaven is to lie in a warm bath and study a seed catalogue.

*I myself fall asleep thinking of what gardening I will do next day or mull over the future of what I have started
The thrill when a difficult plant flowers

*Gardening brings moments of pure joy. The first time you see new roots on a cutting will bring an ecstasy never to be repeated although always bringing huge satisfaction. A first new flower on a precious plant just the  same.
And cooking them too

*Eating your first homegrown tomato. You own vegetables however manky will always be delicious.

*The feel of fresh air and solitary reflection.

*The creation of a new or changed garden in your own image

*Transforming in a day by hard labour a weedy patch into a beautiful picture. (A way of gardening that I myself do not approve)

*Watching an ever changing image as the seasons unfold or merely when a dull patch transforms as the sun shines

*The allotmenteer who leaves his worries behind and meets his mates.

*The warm feelings when you share your passion and/or show off your garden

*Getting your hands dirty and the smell of the soil

*The endless progression as you learn something new

I love this quote from The Garden Jungle by Dave Goulson 
"My garden is a little corner of the earth I can control, small enough to comprehend where I can make things right"
What makes a good gardener?
It does not really matter.
A very good gardener
 When I set out to write this post I had the intention of offering a few pointers to what special attributes a good gardener possesses. When I started to list these features it all fell apart. They don’t hang together. Superb gardeners proceed in diametrically opposite directions. 
For every attribute I can think of, I go to a good gardener who is different
Brenda gardens when it is not wet, windy or cold
I would like to think I am a good gardener myself and yet every day Brenda tells me how I am not
Perhaps the greatest thing about gardening is that we are all different and so are our gardens and the pleasures we get from them. You can be a garden lover - even an expert - without lifting a finger!
Some gentle scarifying?
Perhaps a universal attribute of really good gardeners should be that they recognise the skills and endeavour of others. Things might not always be to their personal taste but quality shines through.
(Except that a few are  scathing and intolerant. Gardening for some brings out our worst competitive instincts)

Where wise men fear to go fools step in. So purely for your entertainment here is my opinionated offering of things that make a good gardener
Sue Garrett is a superb gardener and a brilliant blogger
Doing jobs at the right time - not only on a seasonal basis but day to day decisions,  Is it dry and windy?  -  hoe. Is the soil wet? - plant (not if you are a fluffer). If it is a still day consider spraying.

When doing routine maintenance don’t just tidy for the day but consider long term development. 
Inspection time
A good gardener’s plants will be healthy. He might never spray but by doing things right his plants grow well.

Understanding watering. It takes a good while to learn. You get to the stage that just a casual glance will tell you a plant is in need.

Listen to advice but make your own decisions and always be prepared to try something different.

Love you soil, even if that means leaving it alone. All soils are different and your own deserves your understanding

For many gardening tasks such as weed control a ‘little and often’ approach might be best. (not for watering)

A good gardener listens to his plants and treats them accordingly

Be generous to others. The best way to preserve your plants is to give some away.
Just as well I gave Peter Williams this rare dicentra

In the last month of his life philosopher Franz Kafka with terminal TB retired to the country. He said he had never known such happiness as tending the garden at that time.


Read how Alan Warwick raised a sensational new weeping tree

Learn the correct name of that yellow dicentra


Wednesday 1 January 2020

My throw and grow colour kaleidoscope - Year Two

The problems of continuity 

An early splurge of orange - other colours followed
Last year I posted about my new hardy annual feature and if you missed it, it is best to read it now.  (You will be able to click back)

It was naughty of me to call it a meadow.  It is really just  a hardy annual  border but one managed on naturalistic lines. I did mix in a little fescue grass but it was completely overgrown.

There are several things I want to pick up on, not least how local authorities might differ from the home gardener in their management  bearing in mind we gardeners are there everyday to pounce on a stray weed whereas municipal gardeners are never there. After all it is supposed to be low maintenance. Dream on.

Many recent and very popular municipal roadside displays of direct sown annuals really are magnificent and in the first year are no bother at all. I wonder how they manage continuity from one year to another.
Do they need to resow? How do they tackle the inevitable perennial weed that will establish? Do they dare use glyphosate between seasons on what are (wrongly) perceived as natural features? How do they tackle the prolific annual weeds such as fat hen, sow thistle and shepherds purse that grow and self sow so freely amongst the colourful flowers - potentially becoming worse every year. Perennials such as nettles readily self sow too if allowed to do so.

This fat hen must not be allowed to self seed!
On my own patch I will describe how this year it was almost completely self sown - I did not sow fresh seed other than a few whimsical extras. How long can I continue before some subjects are lost and the more vigorous becomes dominant?
On a different note I observe Peter William’s perennial wild flower meadow each year changes its character.

I was lucky that in April and early May the soil surface was constantly wet and the seed got a superb start. Nature sows more densely than I would ever do. A very good thing and if the odd seedling got trampled if I pulled out a weed or aimed a delicate spray no matter.

A touch of colour in Lyndi's field
In contrast I scattered some seed in Lyndi’s field in early May when unfortunately the soil was starting to dry and germination was poor. On a small patch at home gardeners might choose to water if the weather turns dry. There might be ample water in the ground to sustain growth but insufficient surface wetness to get the seed started.


A few large weeds have been hand weeded away
In this my third season there were more weeds from seed than before.
In my half-hearted first season in what had previously been my vegetable garden managed with my ‘no dig; and ‘no weed seeding’ methods I had an extremely clean start in terms of absence of weed seed. The annuals were broadcast as is my normal practice - unlike traditional methods where in conventional hardy annual borders the clumps are usually sown in seed drills to facilitate hoeing.
It was easy that year to hand pull the odd weed!

I do feel that the ‘throw and grow’ seed mixture was not immune from weed contamination and in the next year I did find certain new weeds resident in my garden. I must have missed them in the first season and they took to their new home.
When you have solid masses of flowers it is much more difficult to stop weeds seeding. I try my best but even I miss some and I anticipate possible problems in future years.

I find that seeded nettles thrive in my ‘throw and grow’ regime. This year and last I have spot-treated small clumps of nettles with carefully directed glyphosate. Quite easy as you get into Summer and some of your flowers start to ‘go over’ and the odd trampled annual grows on anyway! (Indeed I twinkle through the display to pull a few carrots on the far side)

When I pull out my weeds I just throw them down to desiccate and die. Although my annuals are on very fertile ground and in theory might be better on soil of less fertility I am unable to break a habit of a lifetime of enriching the soil by casting down weeds! Where a large weed has slipped through and is already prolifically seeding it is best to remove it!
At the end of the season and before new self sown seed starts to germinate from March next year one has a completely free run for easy weed control! Do not neglect this opportunity to tackle all weeds.

The flowers

As previously mentioned they are (mainly) hardy annuals and not native wild flowers. They very well might be if I had originally chosen such a mixture. Peter Williams observed today that some of the annuals might very well be another country’s wild flowers harvested from meadows.

Not in the original seed mixture these short lived perennial violas sow themselves
Actually I found my mixture was not wholly hardy annuals. I have spotted a few biennials and a lovely orange wallflower two years ago held on to flower in the next April among the new seedlings.
Today in October I spotted a few cosmos which in my book are half hardy annuals.

Bold commelina flowers up to each lunchtime
My own variations have also intruded and have self seeded in amongst the melange. Lovely short lived perennial commelina adds splashes of gentian blue. A few dahlias wandered in last year and proved to be hardy. I will this time deliberately scatter some more. 

Self sown dahlia in its second year
That lovely annual grass that Brenda constantly harps on about when it self sows in other parts of the garden is in there too.
Anyone know what this invasive foxy grass is called?
Last season from May was hot and dry. Many of the flowers had after three months completed their life cycle. Ever tidy Isobel whilst admiring the flowers, delicately inquired what I do with the strawy dead yellow or brown stems. It would be easy to pull a few handfuls out - and indeed some found their way to Lyndi’s field and Cathi’s verge as seed sources. 

Late germinated alyssum pervaded the whole plot with a scent of honey
Late Summer rains brought new germination. A refreshed white carpet of honey scented alyssum was an Autumn joy and dwarf nasturtiums came into their own.

Nasturtiums and second flowering of Salvia horminum
Calendula also comes into its own in late Summer

Winter management
In Autumn of the previous year year I had mused how I would clear up the debris at the turn of the year and how hard it would be. I should not have worried, the strawy remains frittered down to almost nothing. It was work of just a few minutes to rake off shrivelled vegetation and leave any promising seedlings and still green plants.  I had a clear run to spray off any weeds and up to March this opportunity continued.
I wonder what local authorities do at this juncture? A York roundabout which had had a very successful season looked rather scruffy in December but not untoward. I expect that in April they will remake a seedbed and resow.

Myself I shall yet again do zero seedbed preparation and just wait for my annuals to emerge. There will be copious seedlings but will they maintain a suitable balance? Perhaps I will top up with a few favourites? 
And when should I sow them? New self sown seedlings start popping through in March

Originally from the farm field corn marigolds will be back

My original post when I stopped growing most of my vegetables and scattered a few annuals
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