Benefits of worms

Repeat week Golden oldies
This week I am reviving four old posts. In this case to supplement my new post about earthworms published two days ago

Wonderful worms

I am passionate about earthworms. Just ask my former students!  A few years ago, the New Scientist reviewed a delightful book about worms by Amy Stewart. I recommend  it. It’s called ‘The Earth Moved’. Un-be-known to me, Brenda noted it as a potential Christmas present. She went to the bookshop and the assistant checked on her computer. “Oh yes madame, we have it, you will find it in Fiction!”

Minimum cultivation methods are repeatedly shown to increase worm populations. Why are those people who care about worms, not up in arms about soil cultivation which destroys worm habitat? Where are the protests against rotavators that shred worms?

This March, all soil surfaces in my zero cultivated, glyphosate-sprayed, cemetery garden were completely covered in earthworm casts.

Worm populations

These are hugely variable and dependent on a myriad of factors such as  rainfall or drought.The following numbers of worms per square meter are a very rough guide -

• cultivated soil, 150 
• no till management, 300 
• grassland, 500, often considerably more

Counts in excess of a thousand per square meter are not uncommon. Darwin was wrong! Never did I think I would write these words about my all time hero who did more than anyone else to research and promote the merits of worms. It’s just that even he underestimated how many worms there can be. Agricultural grassland can contain a greater weight of worms than the cattle that graze!

Benefits of worms

There are many species of worms. More than 150 of horticultural significance worldwide. All have varying habitats, many in most unlikely places. Perhaps the two most common to gardeners - both usually graced by their latin names - are the night crawler, Lumbricus terrestris and the brandling or tiger worm, Eisenia fetida. The night crawler may be found all the way down to a couple of meters, whereas eisenia is found in decaying vegetation and manure and barely survives in a mineral soil.

The benefits of worms to the soil are huge.

• Their tunnels permeate the soil and provide aeration, drainage and easy root penetration.
• It has been pointed out by Bill Mollison, a founder of Permaculture, that as worms move through the ground they act like pistons sweeping air through their tunnels.
• They redistribute organic matter and in particular pull surface vegetation into the ground.
• They intimately mix soil particles and organic matter in their gut. They create water-stable aggregates (crumbs) of sand, silt and especially clay.
• Nutrients are concentrated in their castings. Compared with figures for surrounding topsoil there are enhanced levels, typically nitrogen x 5, phosphate x 7 and potash x 11.
• They shift soil! A  single worm might cast as much as 5kg of soil in a year!
• Some species destroy harmful soil nematodes in their gut.
• Their casts are rich in biologically active microbes.

It’s not all good

Could it be that worms are ever unwanted?

• Because some worms cast at the soil surface green-keepers do not like them.The same casts are of huge benefit when they occur in the none-digger’s vegetable garden when he wishes to make a tilth. For the domestic lawn, I believe worms to be beneficial. I was a little taken aback at the criticism of my recent  post when I mentioned that my use of iron sulphate as a moss killer also discourages casting worms. My critics have a point, but I would argue that the effect of iron sulphate on overall worm population is small and does little harm to the deep crawlers. The surface casting types - the minority -  just migrate to my borders. Compared to the huge shifts in worm populations caused by the environment and meteorological factors the detrimental effects of a gardener’s activities such as his limited use of fertilizers and weedkillers is small.
• Some gardeners worry that worms might clog the drainage holes in their pots. I have no such concerns and just ignore them.
• The burrows they create has been known to destroy earth dams!
• As described in Amy Stewart’s fine book, introduced none-native worm species, can destroy natural woodland habitat. Worms’ very efficiency in mixing organic matter into the soil removes surface decaying vegetation, the natural niche for many wild plants.
• They bury things! I am being a little frivolous here! My thirty year old rock garden stones in my previous home virtually disappeared! Whenever I shift logs that have been standing on the ground I see evidence of the soil that earthworms move. Could worms be a partial cause of the burial of archeological remains?

The base of my log-pile becomes infiltrated with worm casts. Here an upturned log exposes worm casts on the ground

But some good news for gardeners!  Although many fine public gardens are host to the New Zealand flatworm, (they just don’t tell you), this dreaded nematode predator of worms is not proving to be the scourge we once feared.

What can the gardener do to encourage worms?

• Don’t dig!
• Leave dead weeds, leaves and other  organic debris on the soil surface.
• Mulch.
• Many worms like a neutral or slightly alkaline soil. Their digestive juices need  calcium. On acid soil applying lime may help.
• Grow plants! Perhaps in my post about green manure I neglected to mention how  good it is for worms. And they love clover!
• Add garden compost and well rotted manure.

Worms like untidy gardeners

Two East Yorkshire Open Gardens May 6 and 7; Weathervane House and Boundary Cottage

Seaton Ross Gardens

Two close together gardens for a fiver on the bank holiday weekend
(This blatant promotion will self destruct after the event)

Peter Williams' two acre garden garden at Weathervane House is looking its brilliant best. 

Rhododendrons love our acid soil

My own acre garden is the junior partner this time.  Refreshments are only at Peter's. I am not officially open on the Monday but keen gardeners may informally walk round

My sandy soil does not get muddy but sturdy shoes or wellies are recommended.

It's been very wet and a small corner is flooded!

Plant sales only at Peter's

Information about Yorkshire arboretum open garden scheme and details about our two gardens is on the arboretum website

One of many articles about Peter's garden on this blog

Some just come for the cakes

Further date for you diary

Peter will be informally open on this occasion

Do earthworms improve drainage?

....and where have our local worms gone?

My post today contains few facts, just stories and pure speculation.

When we moved into Seaton Ross my former wife brought me a can of worms as a gift. I hasten to add it was an act of pure kindness. The sandy soil at that time appeared devoid of earthworms. This was pure delusion. In a dry soil in late May they had merely gone deeper. Well below how far a none digger would go.

I dug an inspection hole on brother-in-laws' heavy clay soil and out popped a worm

How deep do worms go?

My memory dims and I no longer recall why I should be guiding a party of gardeners round the Liverpool Garden Festival in 1984. For the record that great garden festival with its associated land restoration received three and a half million visitors

After concluding my tour when even then I was spouting about no dig I got accosted. A voluble old organic farmer had overheard me and grabbed my attention for the next half an hour.

No dig of course encourages worms and this fascinating farmer did not plough. His thesis might unkindly be described as ‘a bee in his bonnet’. 

He rightly declared that ploughing, especially when carried out when the subsoil was wet creates impenetrable pans of compaction. These impede roots, water and worms. Worse in his opinion, farmers needed as a consequence of excess water to lay drains to take surplus winter water away.

Not only do plough pans in Winter create waterlogged conditions, the water that consequently has to be  drained away deprives the deep soil of water. In my organic friend’s opinion this was a loss of a huge water resource in summer. If only all the winter water penetrated deep down and in summer the roots could get to it.

He claimed that on his own farm minimum cultivation had worked for him. He had dug down and found worm channels  six foot deep and roots of farm crops too. Needless to say his worm populations were huge.

How deep did his worms go?

I have to say that his opinion is not the conventional view. What a lovely idea that water is conserved and run off problems assuaged. There may very well be many sites where his vision is valid. 

We have had a local drainage problem this year

My mind hovered around this organic farmer recently when in this very wet season local farm fields have held standing water for months. The ditches have been full but now that they are lower in some places water still stands. (A problem of water penetration rather than removal). What happens to the worms when their soil is saturated for long periods? Many must die. On our own sandy soils surely some of the deeper worm channels collapse. Is it a vicious circle where loss of natural drainage channels exacerbate the problem?

No doubt in summer conditions worms will return. Would there be more if our local farmers did not plough?

Gardeners get together

When old gardeners get together they talk about worms. Recently three of us dined together and subsequently inspected Peter’s garden. David Willis observed that like in his own garden Autumn leaves seemed to be lingering longer than normal. Was it that after this wet season there are less worms of the kind that drag leaves into the ground?

All my own Autumn leaves have disappeared

Back at home I saw no evidence of this but as readers will know this year almost all my shredded herbaceous tops have been left on the surface as I try to reduce labour in anticipation of my impending dotage. It looks very scruffy as most of the debris remains. Have all my leaves gone as my numerous worms built up by years of surface recycling of fresh vegetation have taken the easy option by eating the leaves rather than the tougher fibrous debris?

Roger, dream on

The worms will move on to my rubbish when decaying bacteria get going and the birds will have a field day building their nests - and perhaps eating a few worms!

Delicious

As I said, today just questions, no answers.

Link

As this piece about worms is mere waffle I am tomorrow republishing my more serious previous post about earthworms. An early view here

Four golden oldies this week

My republished post about worms is the first of four reprints this week! I have delved into my archives and in the next few days I am republishing four and taking a break.

Not that you will notice.

Work for the worms on Mike's Foggathorpe clay

Wrong kind of worm

Where are the worms?

Late addition, try Anemone nemorosa, the wood anemone and replant it now

Opens to the sunshine

I might have added this to my last post about naturalising dwarf bulbs but it was getting a bit long….. and Anemone nemorosa isn’t a real bulb!

Peter Williams is wild about good garden plants growing  er - in the wild, and even more so native plants good for the garden. Remember his picture last year of a huge clump of Dicentra formosa in Ray Wood at Castle Howard that had grown undisturbed for forty years.

Enough to excite Peter. How did it get there, a wild clump by the road?

In this case he took a ten minute detour on our way to the lecture at the Yorkshire Arboretum also at Castle Howard. He wanted some pictures and when he had previously spotted the wood anemone growing wild by the road he did not have his camera. (no matter the iPhone in his pocket).

Not as big as the drift of dicentra it was a strong growing clump of a square metre or so. Completely isolated, where had it come from? From a stray rhizome or was it the site of an ancient wood?

Wild at the roadside

If you buy Anemone nemorosa as an alpine in a pot it looks such a delicate plant. The nurseryman had no doubt potted up a tiny sprouting rhizome. Get it going in the garden and if it were not so wonderful it would be a bit of a thug,

It has a very strong almost woody fibrous strong root-like rhizome and after a year or three a new small plant will make a very fine garden statement every early April.

I have been transplanting my own Anemone nemorosa this week!

Even though my soil is very wet and the plants are coming into flower. Indeed on my sandy soil plenty of moisture is needed to get it going

One of my clumps has been under water since Christmas. See where I took out a spadeful.....

...... and teased out divisions and here it is the very next day in my new project of growing in grass

It is a really tough plant. I originally propagated mine along with a single-flowered peony from the only surviving garden plants in the then overgrown Bolton Percy cemetery forty years ago.

Original clump in Bolton Percy cemetery. I persuaded Jackie Giles to divide and plant a couple of spadefuls yesterday. The soft undug very wet clay soil was excellent for slitting the pieces in

This year one of my now large clumps has been flooded for three months and is now flowering as normal. Last week I transplanted some pieces all over the place. I have even enthused the team who now maintain Bolton Percy to do the same from the original cemetery clump.

Some garden cultivars and similar species

Thank you Peter Williams for these

Peter's posh totty

Links
Peter Williams' clump of Dicentra formosa at Castle Howard
Last week's post about naturalising bulbs
A very early blog effort where I jump on wet soil

From the ridiculous to the sublime about gardening when it is wet

Naturalising dwarf bulbs

Mainly about bulbs such as scilla and chinodoxa that seed themselves around

I love rampant mixtures

I adore all those spring bulbs that take up permanent residence in the garden. I have written extensively about establishing narcissus, tulips, hyacinths, bluebells and snowdrops. My recent post about establishing bulbs in Lyndi’s field is almost my most popular ever!

A handful of anemone bulbs in Lyndi's uncultivated field emerge in their first year

My purpose today is to concentrate on those bulbs that as a result of prolific seeding and given time will cover the garden with sheets of glorious colour

White in this case

I am sorry to repeat myself that success in naturalisation comes readily to the none digger. It is he who has glorious carpets of Cyclamen hederifolium and coum. Bulbs go dormant  and get forgotten out of season. Only the very most vigorous subjects withstand careless disturbance. (Although I might mention Peter Williams mistakenly stirred around his Dicentra cucullaria and now has a magnificent clump and  I know of a commercial grower who lightly rotatavates his snowdrops in summer every few years to propagate them).

Undisturbed clean soil, gravel mulched zones and light grassland are the places for naturalisation. Coarse grass is too competitive for most bulbs but thin grass in woodland might work very well. So too where in the popular fashion low grassland fertility is maintained for ‘wild flowers’. I must admit such starvation goes against the grain with me and this year I lightly scattered fertiliser over my Cyclamen coum!

Happy accident

Some of you will know of my current enthusiasm for creating pure stands of Chewings Fescue grass. In such swards I expect naturalised bulbs I have recently planted to do very well.

Although my emphasis today is to encourage those bulbs that self seed almost all bulbs are best first established as a result of vegetative propagation. With a sufficiently generous budget you can plant thousands of bulbs and cover the ground in a single season! 

A field of this double snowdrop must have arisen by vegetative propagation

It is much more satisfying to let natural division and where possible self seeding increase your stock every year. The most beautiful stands take decades to establish. Some famous collections of snowdrops have been there for more than a century. Although snowdrops are an example of bulbs that can seed themselves you will find most stands are at least in part genetically uniform. This indicates vegetative spread with the help of rabbits and other natural disturbance. Crowded snowdrops (and bluebells) get pushed to the surface and nature does the rest.

Certain bulbs eventually make generous crowded clumps that will only spread more widely with the help of the gardener. After several years I would encourage you to lift and replant them

This fritillaria is far too densely crowded and is best spread in clusters over a much greater area. Do it today 

Growing bulbs from seed

Prolific self sown seedlings

Peter Williams' aconites have self seeded in his path.

It would take a very long time to establish drifts of bulbs from a seedsman. Packets are small and some of the seed doubtfully viable. Never-the-less it is a fun way to introduce rare plants to your garden

Scilla biflora seeds very freely

What I envisage today is large quantities of fresh viable seeds produced in situ and naturally cast around. If you are lucky enough to have access to free seeding subjects you can also either scatter seed yourself or get your bulbs started by sowing in a pot or seed tray

Winter aconite freely self seeds

The list of bulbs that seed around freely is not a long one but the few that do are very worthwhile. There are several species and distinct cultivars of scilla and chinodoxa that cover the ground with flower after just a few years. My own personal favourite is Scilla biflora, readily available as bulbs to get your stock going it is extremely prolific. Spread by ants many gardeners have Cyclamen neapolitanum all over and if it likes you Cyclamen coum too. If you are very lucky you might get winter aconite going. It does not take many years for you to curse an excess of bluebells! You will need to be very patient for Fritillaria meleagris to clothe  your wet areas; not so chives which grows like a weed.

Beware real weeds such as ransomes and certain alliums!

The best naturalised Cyclamen coum I know is on a clay soil

Scillas naturalised at Anglsey Abbey

The secrets to successful self sowing is to allow your bulbs to completely die down without cutting or tidying debris away, to have excellent weed control, accurate recognition of seedling bulbs and not stirring the soil after the tiny new bulbs die down. 

Collect seed of Acis autumnalis and sow in a seed tray or divide clumps in the green and replant immediately

There are several bulbs that set fertile seed but do not successfully self sow. There might be serendipity factors such as insufficient seed volume, variable weather conditions and excessively dry soil. Such seeds are best collected and sown in a seed tray. I do this for fritillarias and Narcissus romeuxii and in the past cyclamen for eventual sale on my open day. Peter Williams has been very successful with acis which flowered in its second year.

My own method is to sow up to 200 ripe seeds in a seed tray immediately on collection and place them outside or in my cold greenhouse. Almost invariably they require the winter cold and germinate in late Winter or Spring.

Initially in the unheated greenhouse they complete their first season undisturbed in their tray.

Vegetative propagation

I started my Scilla biflora by planting bulbs which freely self seeded

Lets face it many bulbs spread best by vegetative propagation. Many bulbs, corms and tubers are very cheap to buy. Take Anemone blanda. Provided you buy and plant small handfuls of bulbs at the very start of their sales season and after soaking for 24 hours you will have attractive clumps in their first year. After not very many years natural vegetative spread will give you lovely late spring ground cover all over your borders.

(Researching this post I had found a report on the net that Anemone blanda did not self sow. Peter Williams marched me round to his own garden and pointed to hundreds of newly germinated self sown seedlings)

Transplanting

I took out two large spadefuls and immediately replanted as two large clumps to make the drift larger

I teased this spadeful of fritillary apart and planted small clumps

The double sin of transplanting in full flower and into wet soil

Most dwarf bulbs can without check be lifted and planted ‘in the green’. I do this at any time but it might be best just as they emerge or as they die down. This year in a new project I have been lifting and dividing scillas, chinodoxas, snowdrops, and eranthis in full flower. 

With immediate replanting within the garden dormant bulbs can be replanted at any time as long as you can find them! Not so for such as dry bulbs of snowdrops or cyclamen from the garden centre

Chinodoxa has done particularly well this year

Winter aconite brightens a February day

Dogtooth violets thrive in Peter Williams's light woodland

Credit most of the pictures are from Peter Williams

Links You will find bulb seed in Chiltern's catalogue

My first stop for first class bulbs in quantity is Parkers Wholesale - but not so sure about their plants

Use my search box to find my articles about daffodils, snowdrops, hyacinths, ipheons and acis.