Wednesday, 21 August 2019

Hand weeding

Pete has lovely Julie's help to remove his weeds (and to design and plant his borders)
I think it a mortal sin to let weeds grow large, shed seed and be yanked out together with good soil and placed in the bin. One way traffic out of the garden. I despise the penance paid when such people (I will not call them gardeners) seek to replace such denudation by buying dubious stuff at the garden centre.

I feel sorry for those who through lack of knowledge, prejudice or impatience fail to eliminate perennial weeds such as couch, ground elder and convolvulus and are for ever fruitlessly pulling or scratching away.

I admire those gardeners who have achieved a nirvana where a casual walk round the garden and the odd stoop to pull out a weed gives a shot of serotonin and is all that is needed to keep the garden completely weed free. It will be a small loved garden where no weeds are allowed to seed. Pure joy to love your plants and nurture every wanted self sown flower.

I preach that weed control should be varied and all appropriate methods should be melded together. Each weed has it’s own strengths and vulnerabilities. Ring the changes. Many of you will not share my penchant for using glyphosate which for me is essential for the several acres that I garden and be surprised to hear that I frequently hand weed.

Even a spade might be enrolled (in truth I am dividing an alstroemeria)
I want to talk about this today. I might stray into mentioning a few aids to merely hand pulling but shall ignore valuable cultural practices such as forking out or hoeing. As to digging it might have a place to bury none-perennial weeds on such as allotments, or to dig holes for ceremonial weed burial in a relative’s garden.
I firmly believe that to dig over borders is yet another sin.

Hand weeding

The nicer of my two problem epilobiums
It is almost impossible to pull out established perennial weeds. Hand weeding is more suitable for annuals and short lived seed sown perennials such as my own nemesis that pink wind born invader epilobium.

Brenda's wellies see little weeding
I use the word ‘hand’ rather flexibly. Sometimes it will be my instep or heal. Should I stumble on a patch of about-to-seed hairy bittercress I will scrape my boot over them. The result is the same as if I severed them at ground level with a hoe - and yes, some weeds need to come out completely but most true annuals will be killed by root detachment.

This is all you need to pull out this sowthistle

My cacti grown in garden soil sometimes need hand  weeding with the help of my secateurs to grip them
For those weeds where the root needs to come out grasp the weed firmly and low and gently tug vertically taking care not to snap them.
For tap rooted plants such as dandelion and docks you can loosen them with a spade and grasping the root/stem juncture  pull them out cleanly.

I am cavalier about any to-hand aids to weeding. I will enrol my secateurs to grasp a weed nestling in a pot of prickly cactus. Of course I will wear gloves if I pull out a large nettle or as recently soft thistles growing in my colourful annual display. I am quite prepared to bend further if cutting back with my hedge trimmer or shears to take out an intruder.

My own penchant is to fling the weed over the garden sometimes flamboyantly to the back of the border. In normal dry conditions it will shrivel and die and its goodness will return to the soil. Do not equate this with sweeping dust under the rug in the kitchen. Recycling is good and if the slugs like my scattered weeds that suits me fine (decaying vegetation is more tasty to slugs than are your plants). I prefer slugs and snails to eat scattered weeds rather than my hostas.

It takes only a day or four for the weed to disappear. I doubt if tidy people like my dear friend Peter can bring themselves to do it. You can always take them for compost but oh what a chore.
People fear the weeds will re-root or continue to seed as they die. If the weeds are such that they still have substantial root, or the weather is wet you are probably doing it wrong or at the wrong time. Just use your gumption. If hand weeding is your only method of weeding then you need to do it often or my method of disposal are just too untidy.

Hairy bittercress will not seed in the lawn
(Don’t tell anyone but if it is wet my (few) hand pulled weeds sometimes are deposited on a hard surface, on my lawn or even suspended and hidden in a plant clump! I do drop most pulled weed in a clear space in the border and if they do regrow will be easily nobbled when I spray or hoe next time) 

I know to many of you my untidy methods sound ridiculous and indeed if you are tackling a border full of seeding large weeds when wet conditions prevail they jolly well are. If so just remember they should go to compost and not to the municipal bin! (And if I might say as a cynic, permit you to recycle all those weed seeds when you spread your compost)

When I need to hand weed

Goosegrass is not a grass!

Scramblers such as cleavers. Sometimes in Bolton Percy churchyard or in my own garden creeping over the wall from the farm field I find Galium aparine. You might know it as goose grass, sticky Willy, velcro plant or a profane name of your own. They are fun to pullout, stick together and drag out their brothers and sisters. Only if already seeding do you need to cart them away.

Too many to hand pull

Epilobiums. 75% of my time spent on weed control is spent on this pretty and evil invader. Having eliminated most of the other weeds they just take their place. Their weedy credentials are impressive. Here is their portfolio.
1. Arrive in the air in copious quantities August to October. If any of your gardens flood as mine does it floats in on the water!

2. Germinates profusely at literally any time of the year.
3. Grows in most insidious spaces in all manor of soils and in all conditions from wet to dry.
4.It floats on the air into the middle of your plant clumps where it thrives and right through the summer pops out as if from nowhere
5. It is partly resistant to glyphosate and its overwintering tight mats of shining rosettes almost completely so.

Shiny epilobium hides in the foxglove

If you don't pull epilobium out cleanly the stump proliferates  likes this one

6. If not hand weeded or hoed out cleanly it regenerates into straggly difficult to control irritating snippets. (It is a joy to cleanly pull out in Summer: the tight rosettes in Winter are best hoed undercutting a little more than severance at ground level. In this case in wet weather they might take a few weeks to die, but they do).
7.It is perennial
You might gather I don’t like this willow herb relative and have written about it here


Nettles get into insidious places
Although nettles are best controlled with herbicide they are partly resistant and if you are using glyphosate you need a dose at the top end of the concentration spectrum. Even in a  garden where you think they have completely gone, wayward seeds pop up and establish in the most awkward places. I often need to get my gloves and to delve into the middle of a shrub or herbaceous perennial.

The only way to get rid of this sow thistle is to pull it out
The world is not ready to hear of my obsession with pulling up grass weeds in my lawn. I might sum up courage in my next post on my series on lawns. What I think is more useful is to suggest that if you are sowing a new lawn and hope to create a sward made up of the grass that you actually sow - a fairly rare achievement - then at first germination weed grasses are pretty obvious and should be pulled out.

This fat hen needs yanking out
In the round for me hand weeding is a spontaneous, generally unplanned action as I walk round the garden. It is pretty frequent and occurs at times at least once a day! It is only for those weeds in insidious and annoying places and those I know are difficult by my routine methods or ones that have been missed that threaten to seed. One year’s seeding really is seven years weeding.

The phantom weeder
Other articles
No links today but I have written before about almost all the weeds named in this article and can be found by inserting their names in my search box. I have also done major articles on perennial weeds such as equisetum, brambles and ground elder. You might want to check out my statement about slugs and hoeing

Saturday, 10 August 2019

Planting density - how close should my plants be put together

I sometimes plant in bold clumps (or unrestricted they become so)
I am indebted to Noel Kingsbury who has written a very fine post entitled ‘Mind the Gap’. He writes as a gardener and professional landscaper. In his case he looks at herbaceous perennials but I would like today to consider woody plants too.
Noel observes that although common planting densities for herbaceous perennials might these days may be 7 to 9 plants per square meter that even these  might be extended. We have evolved from Victorian grand isolation of ‘specimen plants’

I would like to have bold drifts of this one but on my soil dictamnus is somewhat miffy
As a gardener when I consider planting densely I think of the budget. As a Yorkshireman my garden has generally been extended one at a time!
I feel the urge to write a post about how easy it is to bulk up bought plants very quickly in improvised nurseries (buy big plants and divide them) - but not today!

Noel’s methods not only give speedy establishment of a new garden feature but he argues it is more visually acceptable to almost completely cover the ground and is ecological sounder. Some of his friends let annuals seed themselves and intertwine and so do I.

Quick results with annuals
It is particularly important if you are planting herbaceous plants densely you have tackled the perennial weeds. If your ground is invaded with such as ground elder, bindweed and couch you will never get rid of them if intermingled within a dense canopy.

Geranium macrorrhizum (under the tree trunk) provides superb ground cover
These hostas suppress weeds from seed too
On the other hand if you have an established perennial weed free complete plant canopy then weed control becomes much easier as most seedling weeds fail to establish. Indeed you can considerably ease your garden management if you plant areas of more vigorous recognised ‘ground cover plants’. My all time favourite for this is Geranium macrorrhizum.

Peter's borders are densely planted too
When I look round my garden I have fairly dense planting albeit achieved after several years of endeavour. It’s best to fill the borders and relinquish bare soil. 

I have varying styles. My herbaceous borders in Summer are almost impenetrable masses of perennial plants. My mixed borders are more or less isolated shrub and tree plantings with herbaceous underplanting and self sown annuals and short lived perennials. 

You can walk in and around
At times there are bare gaps where bulbs seasonally appear. Some perennials have a short season and they die down at different times. I like where possible to utilise such space more than once in the year and for example clumps of hyacinths are replaced as dormant dahlias appear in their place.

You can walk between the plants in Bolton Percy cemetery garden
Elsewhere I have several ‘walk in’ features mainly gravel mulched where the above principles also apply but there are more high-light requiring flat drifts of herbaceous and alpines in transient open spaces. Where clumped together surrounded by empty spaces there is less competition for water than in a completely dense planting. This is a design consideration in low rainfall places.

Planted as one small pot I have had to reconsider the border design as my tree heather has grown
In my ‘acid border’ shrubs such as azaleas scramble together and are under invaded by low growing plants and shrubs such as heathers. Noel would be horrified that my heathers over the years have been planted one at a time. Those of you with a more generous nature will plant 3, 5 or 7 (if you are fussy about odd numbers). Noel will probably plant hundreds.

Rather unruly
There are a few other places where my shrubs mass together to make elegant competing compositions - and Brenda walks round and declares she cannot define their individual outline and gets out the secateurs or orders me to prune out some branches. Indeed exuberant competitors do need adjudication - and that includes both of us too.

If a cold Winter kills my six year old bottle brush it leaves an empty space
The question is how we get from an empty garden to one of pleasing easy maintained maturity. It can take years and the best gardens develop organically. I never paper planned mine.

Woody plantings
It is inevitable if you are planting slow growing shrubs that will take years to mature that you will plant quite densely to achieve immediate effect. If you move in to  an already existing garden do not strip everything away and start again. Leave existing plant structures for temporary shelter and beauty. You might find you keep some for ever. Wait to assess existing dormant plants.

Some of your shrubs at planting time might be more vigorous than what you eventually require. I have never quite understood the value of nurse planting where such plantings might protect slow growing neighbours.If you are not careful they are more likely to outgrow them. 
It is inevitable however that some of your shrubs will be slow growing and take several years to achieve their grandeur and might start off with more vigorous neighbours.
I don’t discourage dense planting for the short term but do encourage close monitoring and eventual thinning out by removal or reduction by pruning.

Love in a mist all over the place
A domestic problem I still have is that my plantings are littered with (in my view) beautiful annuals such as nigella, euphorbia and corydalis but that Brenda regards them as undisciplined intrusions. They do of course need careful management. I just bite my tongue when they are pulled out prematurely!

Somewhat undisciplined
They say not to put large plants in narrow borders but I do not agree
Noel's blog gave me the idea to write about design today

Saturday, 27 July 2019

The magic of silicon

The nutrient that isn’t - but (for the sake of the planet) ought to be

There is more silicon in this equisetum than all its other soil absorbed nutrients put together
Spoiler alert, my post today is unlikely to improve your garden one jot. It is highly unlikely your garden is deficient in silicon. Next to oxygen it is the commonest mineral on the planet and for most British soils, plants have free access to it. The mineral content of my own soil is almost all silt/sand - almost pure silica rock.

The boffin’s definition of a plant nutrient is a mineral essential for a plant to complete its life cycle and is a constituent of a least one cellular structure. (I am not sure how completely essential potassium satisfies the latter criteria)
Silicon fails both tests. Plants in hydroponic solutions grow perfectly well without it and to all appearances it appears in the plant only as elegant crystalline deposits.
One might add in most laboratory containers such as glass ones, it’s almost impossible to avoid the presence of very small quantities.
The cynic might claim that our laboratories who omit silicon in their hydroponic nutrient solutions create plant artifacts and then draw false conclusions. Such conclusions might have worldwide significance.
The undisputed truth is that grown in the soil plants absorb substantial amounts of silicon. Levels comparable to that of the major nutrients. Sometimes very much more. Ten percent dry weight of plant tissue has been recorded in certain grasses!
It was once thought that silicon merely entered and was passively dispersed in the plant with the movement of water. It is now known that like recognised nutrients it is actively absorbed. What’s more this very insoluble nutrient is within a soil’s biosphere  converted to a solubility comparable to all the main nutrients. 
This high level of solution greatly exceeds that which might stray into scientist’s glass bottles - unless soluble compounds of silicon are added as they not normally are.

Significance in the garden
So silicon is not a nutrient, not necessary for plant growth and is most unlikely to be deficient in your garden. Why does it matter?
There is a small possibility if your garden is on a highly calcareous soil or a reclaimed moss peat many miles away from a supply of wind blown siliceous erosion it just might be. 
Apparently the Everglades are deficient in silicon

You might live in the Florida Everglades or are the proud owner of a rice paddy field. Seriously, there are huge silicon-deficient zones out there in the big wide world.

What is of interest - albeit being beyond your gardening control, is that silicon although not essential for plant growth does wonderful things to enhance it.

Benefits of silicon to plant growth
Most of these are due to its hard crystalline nature and its ability to harden plant tissue. In terms of plant evolution it is much less ‘expensive’ than manufacturing lignin.

My giant miscanthus stands like a soldier without any need for staking
1. Although not essential for plant growth many plants grow better, sometimes very much better, when they have access to silicon. For some crops, yields are increased and for flowers they might be bigger and hang more erectly. 

2. Similarly leaves may present themselves more efficiently to sunshine.

3. The structure of the plant is more stable with respect to lodging down in wind and rain.

4. Silicon interacts with other elements in plant solutions and toxic effects of such as excess manganese are reduced. There are advantages in surviving in polluted or salty soils.

5. The toughening of cell walls make them more difficult to penetrate by fungi and give a much enhanced resistance or tolerance to many fungal diseases.
Similarly parasitic plants are less able to penetrate. This is of huge importance for certain world crops.

6. In a similar vein plant pests less readily chomp tissues and for world crops' breeding programmes are seeking to select for tougher and more effective silicon deposits (phytolyths)

7. Structural effects on stomata enables plants to reduce transpiration in drought conditions

8. Root growth can be increased. 

The latter two points are of huge importance in breeding plants with enhanced capacities to absorb silicon and help tolerate climate change

YESI - York Environmental Sustainability Unit
My new awareness of the benefits of silicon came when I attended a lecture at the Yorkshire Arboretum by Professor Sue Hartley from the above organisation on the subject of  sustainability of world food production.

She never mentioned bees once! Tell that to Monty - for the world’s major foods (rice,wheat maize and potatoes) bees are almost irrelevant! (That is not to say that together with wasps they don’t do wonderful things and we would not want to be without them).

The above picture is take from the YESI website and shows two micro pictures of silicon deposits on deschampsia grass. On the right extra silicon has been laid down in response to pest damage
Sue's lecture reported the benefits of silicon in world rice production where it is already applied as a fertiliser which is commercially readily available as a by product of industry. She showed wonderful micro pictures of the arrays of silicon phytoliths and showed how conventional breeding programmes (informed by gene manipulation) were being used to enhance rice silicon uptake and effective distribution of these crystalline deposits. If you were a chomping insect you would despair for your mandibles.


No shortage of silicon on this railway line
The weed variously described as horsetail or marestail is one of the very few plants that seems to require silicon for long term survival. It contains more silicon than all the other soluble nutrients added together and in almost all of its cells. So much so that one common name is  'scouring rush'. That says it all. Now I understand why it is such a noxious weed on sandy York allotments!

Equisetum hyemale
Silicon is the reason why marestail's hardened surface makes your weedkiller run off. Many gardeners bruise its leaves to increase absorption or use a very fine spray that dries on the the leaf and stem surface.
I wonder if any readers have soils that are too low in silicon for this weed to grow. Such lucky people might have an organic peat soil or one so calcareous that their sand and silt is entirely composed of calcium carbonate. I would be interested to hear. (On second thoughts perhaps I should omit 'lucky').

Silicon helps keep the tubes rigid
You can even buy the stuff
As mentioned, don’t rush out and silicon feed your plants. Silicon is even a constituent of tap water. Beware of siliceous charlatans who will seek to sell you extra.

I think it a mistake to regard silicon as a trace element. Plants use it in much more substantial amounts than that and I think many laboratories who do not add it to their solutions really might jump to suspect conclusions.

Are our own plants in the UK ever deficient? I am unaware that they ever are. I mischievously wonder if soft growth in garden centre plants grown in such as peat or other exclusively organic composts and grown dependent on extensive liquid feeding might ever be deficient. The industry seems to be becoming aware of its importance in respect of plant quality. It would be nice to buy plants that do not keel over and die as soon as we get them home.

Another straw in the wind of the benefits of tissue hardness is that one Dutch turf breeder now classes his grasses from hard to soft. Grasses are being bred and graded with varying silicon geometries.

So what about my title "for the sake of the planet?" The world's most important food crops are all grasses which contain much silicon. Some of the world's soils are deficient. 
Improved silicon uptake by either fertilisation or better absorption and utilisation as a result of plant breeding have great  potential. 
There is a perceived need for less reliance on pesticides in newly bred crops. Tough silicon tissues might fulfill some of this need
There is a need for greater plant drought resistance and tolerance to climate extremes. Stronger root systems seem to be promoted by the action of silicon. (Perhaps it is no surprise that gardeners marvel at the depth that the roots of equisetum goes to). 
There are huge crop losses due to crop's lodging over.

There is innovative research proceeding on all these fronts that involves silicon.

Better silicon nutrition might very well have a role in feeding the world 


Forgive me for demoting bees as agents of world food production. I really do love them

I rambled about hard and soft growth

I hope YESI do not mind me using their picture

My opus on controlling equisetum

Wednesday, 17 July 2019

Leaving Dahlias in the ground overwinter

These dahlias have remained in the ground for five years now and.....
...  were all raised from seed
The normal way to overwinter dahlias is to lift them after the frost turns them black and to store in a cool frost free dry place. Not one for following careful instructions it has not been always successful for me. Well documented elsewhere I do not propose to describe how today!

A beacon for drivers for five months of the year
For several years now I have left my dahlias in the ground. Not always successful I do have by now strong plants that I can more or less rely on. Some have survived for up to a decade. Through the last two mild Winters I have not lost a single plant and with self seeding my stocks have increased.

Would any survive another 2010 Winter when temperatures of minus 20 centigrade persisted for six weeks or more and cold penetrated deep in the ground? They would not.
I would buy some more and start again. 
No doubt there has been some self selection of the hardier kinds. Those that have come back each year have liked my conditions. In passing I might mention their are some species of dahlia more regularly regarded as hardy. A particular favourite is Dahlia merckii.

Over the wall Dahlia merckii sets off 'wildflowers' in  the farm field
Last year this Dahlia merckii sowed itself here
If you live in colder areas than I do or have heavy poorly drained soil my methods will not be suitable for you. If you live in the balmy south-west I suspect it is the normal method.

 I would love to hear reader’s experience and receive their opinions. I don’t live in hope as other than my much loved and appreciated stalwarts most readers seem reticent to offer an opinion. I often feel I have failed and my only conciliation is that many other garden bloggers share this frustration.

How things have changed
Seed-raised from The Bishop of LLandalf

In my youth I would have considered leaving dahlias outside through the Winter as foolish. I also considered them gaudy floppy labour intensive things not for me. I now truly love them and regard them as an essential part of my summer garden totting up  almost five months of continuous flowers. (My best performance being mid June to the beginning of November).
I remember I once had a client who by neglect had failed to lift her dahlias in a very sheltered part of her York garden. I was amazed they came back every year and thought it a complete aberration! 
What has changed? Is it climate change and warmer winters? Is it just my expanded ambition? Are modern varieties tougher?
I am told that Victorian gardeners knew that if buried overwinter below the level of soil freezing they would survive in the ground

Making it work

This one is tall and floppy and needs staking
Dahlias will fail to overwinter if your drainage is poor and there is excess water at the depth of the tubers. My soil is sandy which makes it very suitable. Even so the lower parts of my garden are too wet and I have learnt by success or failure where they will happily survive.
I suggest when first planting you plant them as a green plant and quite deep a couple of inches more than normal - or even much more. I was told that way they subsequently form new  tubers deeply. I have doubts whether this is true and many of my plants are undisturbed self sown seedlings. 

They are a bit of a jumble, Brian
Reader Brian Skeys kindly sent me seeds of a lovely extra-hardy dahlia strain and the three plants I raised have now made up to a dozen - and extended their range of colour. (Brian I have forgotten their name, if you are still there perhaps you would tell me?).

The bishop spreads himself around in diverse colours
The bishop’s children (legitimate and illegitimate offspring of The Bishop of LLandalf) have established the same. I think that like the more tender varieties of alstroemerias, dahlias make ever deeper tubers as the years pass by.
Each year the plants get stronger and with multiples of growing points are less likely to need staking. One or two of my taller ones flop all over and Brenda shouts at me when she needs to put in a stake.
We frequently suffer from late spring drought. There is no problem with my dahlias, the roots are already down.

Dahlia 'Magenta Star' in Peter Williams' garden
It is quite easy of course in late Spring/early Summer to shove your spade in deeply and take out a large segment to replant as new stock. So too with a sharp knife take cuttings going deeply to a fleshy white base (not essential). Use your favourite method of rooting preferably under glass.
In early June this year I took advantage of the wet spell to transplant some young plants that had seeded in the wrong place. Young dahlias transplant very well with very little check to their growth.

There might be some merit in mulching over with such as insulating autumn leaves or straw when your dahlias die down. I half heartedly leave dead tops intertwined with Autumn leaves  that I rake over the top.
The trouble with such insulation is that continuous frost for a day or so soon penetrates through. Your own overcoat keeps you warm because there is a heat source from your body within. Heat stored at depth in the soil is very small.
My none mulched plants come through just the same.

Pest Problem

Ugh, black bean aphid (I assume)
Although I claim leaving dahlias in the ground will be more healthy than overwintering dry and will have less fungal disease such as root rots and subsequently all the perils of humid greenhouse conditions and pest presence, last year I was not immune!
I was caught out by these aphids. In the picture they are already moulting. I know you can control black aphid on broad beans by pinching them out at the tip of the shoots, thereby restoring the natural balance with hungry predators. I had to go a step further here and cut them half back. They soon made new strong growth and were as good as ever.

Back this year
Alerted this year by blogger Sue Garret who reported that she also had suffered black aphids on her dahlias I rushed out to find in mid June just one infected plant of my own. I snipped it away.

Healthy bishop children in early June

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