Wednesday, 26 November 2014

Continuing to raise the allotment with trench Hugelkultur (4)

I had just scraped up the last of the woody shreddings and put them into the wheelbarrow when I got a call from the gate by a gardener with a load of woody shreddings.  Opportune or not? They backed the lorry into the carpark and tipped the shreddings into my composting area.  This will last me about a week or two.

It was great because I was not looking forward to trundling the wheelbarrow down to the main car park to fetch the woody shreddings from there.  A time consuming exercise.

I have nearly finished trenching the first section of the allotment but the final trench is alongside the path where it was full of mare's tail Equisetum arvensis and bind weed Calystegia sepium.  Removing these rhizomes is a tedious and slow task, however if not done with some efficiency it will cause a lot more work in the future.

It is reported that leaving even small pieces of the rhizome in the soil will produce regrowth of the plants.

The example of micropropagation shows that plants can be generated from the smallest of pieces of material.  However, I wonder the size of the smallest piece of rhizome that can regenerate plants when in the wild.  Do we accept the assertions of pundits in gardening books and on television or do we investigate for ourselves?

So, when I have time, I will be planting smaller and smaller pieces of Equisetum and Calystegia in ordinary allotment soil using 3 inch pots and keeping them in the greenhouse to see if any produce plants.  I reckon that any rhizome without a rooty node will not regrow.  Further, any rhizome smaller than a particular size will not grow.    

However, knowing these particularly, pernicious plants I would not be surprised if they did regenerate from the smallest of pieces.

I have been amazed  by the number of Stigmatogaster subterranea I am finding in the soil.  I think that it is fairly common in the West Midlands.  They are a good predator of slugs and soil pests so I would like to encourage them.  It is amazing the close interaction of invertebrates like these with the soil.  Worm tunnels fit the worms much more intimately than a hand in a glove.

Stigmastogaster subterranea 
So, it takes a while to remove all the perennial rhizomes from the top soil using the bread tray sieve.  Moreover, I am not stupid enough to expect I have removed them all, but I have been pleasantly surprised how little if any Calystegia sepium or Equisetum arvensis  has regrown on any of the areas of the allotment that I cleared with the sieve last season.
Bread tray sieve.
Mare's tail and bindweed seem to grow well in poor soil where there is little competition from other plants.  Both perennial rhizomes are not seen where there are healthy nettle and comfrey plants growing; primarily because they shade out the mare's tail and bindweed. To ensure that they do not return, I will make sure that the ground is well fertilised and the crop plants form a good canopy to shade out any weeds that might grow between them.

As usual the bottom of the trench was forked over - and I was still removing mare's tail from the subsoil clay.  This plant forms extensive rhizome nets throughout the soil, which means that they can throw up aerial shoots over a wide area wherever there is little competition.   Also this wide ranging net of rhizomes can store a great quantity of food so that even when light is excluded - as when the ground is covered with carpets, black plastic or other opaque sheets, they can still grow from underground stems when the soil coverings are removed.  Breaking up this net by digging will reduce the amount of food that tiny pieces left in the soil have to rely on and this may further reduce their viability.  

In order to increase the fertility and organic content of the soil, I am adding logs, brushwood; processed wooden planks; at least a six inch layer of woody shreddings; comfrey liquid; sieved top soil from the path mixed with a little chicken manure and farmyard manure before pulling the sieved topsoil from the trench back over with the rake.   

I'm not really sure whether trenching like this has any particularly beneficial effect on the yield of vegetables I harvest from the allotment, however it keeps me fit and active.  

I took the oca out today and washed the tubers.  I will keep all of the tubers to build up my stock. They will have to be carefully dried and stored in paper bags until next season. The parsley was planted in their stead because it is a little shady behind the greenhouse.  Parsley will grow in partial shade.  

I may also plant a gooseberry there as well.  

I will have to sort the little greenhouse out because it has sunk even further where I have trenched around it.  It will not take long to remove the glass and raise it up but fitting this in when I am digging is quite difficult.  I will finish digging first.

Friday, 21 November 2014

Continuing to raise the allotment with trench Hugelkultur (3)

There were a significant number of old pallets on the new allotment.  I toyed with the idea of using them to board around the allotment but they have all deteriorated and most of the wood is being decomposed by fungi.

Pallet wood is not treated with preservative or tanalised so will easily rot away.  I have decided to bury it.  Now, this may surprise you knowing my thoughts about burying wood, however I am going to continue to do this until all the wood is put into the Hugelkultur trenches.

The trench top soil dug out today was sieved with a little chicken manure.  This top soil was mixed with top soil dug out and sieved from the paths.  I had planned to remove one spit deep of subsoil from the bottom of the trench but found the Hugelkultur I did earlier in the year.  All the wood was decomposing well so I decided just to fork over the bottom of the trench, mixing the woody material with the subsoil.

As the Hugelkultur had improved the drainage, there was little water at the bottom of the trench and it was relatively easy to turn the soil over.  More shredded woody material was added as a six inch layer to the bottom of the trench.  Neat comfrey liquid was watered over the shreddings and a thinnish layer of topsoil was pulled over the woody material.  Farmyard manure was then added to the trench and the rest of the topsoil was dragged over the manure with the rake.  

The hole in the path was filled with a blue plastic sheet and lots of stones.  The top of the new path is being capped with sandy clay to smooth it off.  The path really needs some shredded bark to make it more passable but I will have to do this another day.

I am quickly running out of shredded woody material and will have to use the shreddings on the car park at the bottom of the allotment site.  This is no hardship, however it does take more time.

The minimum temperature in the greenhouse was six degrees celsius, while in the hotbed frame it was a balmy ten degrees celsius.  The shredded woody material in the hotbed was 26 degrees celsius six inches below the surface.

As I am going to fill the greenhouse with sweet peas in January, I will have to move all the greenhouse plants into the hot bed frame.  It will be a tight squeeze.  There may be room in the small greenhouse but there is a lot squeezed in there too.  I still have to pot up all the chrysanthemums and store them away so I can take cuttings in the early spring.  Also, there will be twelve apple tree grafts and two plum grafts to find a home for.  I would rather keep them protected until the buds break and they get leaves.

Wednesday, 19 November 2014

Integrated pest management for organic gardens

In order to keep plants healthy good soil management is paramount.  Large amounts of organic matter can be added to the top soil to increase the soil microorganism population.  This will increase predators such as the soil centipede, Stigmatogaster subterranean.

Soil centipede
Adding horse manure to potato bed
Manure laid over the topsoil and left for several months
during winter

Manure dug in in February
Digging over the soil exposes the surface to birds, which can take off top soil pests.  Encouraging birds by using feeders and nesting boxes will increase the population of birds visiting the allotment and also their usefulness in removing pests. 

Seeds in feeder to attract birds
Bird feeder on the pear tree.

Green manure covering the allotment over the winter will protect the soil from excessive leaching and give a habitat to small predatory animals.   

Green manure of rye, tares and crimson clover
The brassicae bed is limed to increase the pH of the soil and discourage club root.  

Predatory insects such as ladybirds and lacewings are attracted to the allotment by habitat boxes. Immature larvae of ladybirds and attractants for lacewings can be bought on the internet.
Lacewing box 

Amphibians like toads and frogs, which are predatory on slugs and snails, can be encouraged by creating a pond habitat for them to breed in.

Pond for amphibians

There are several natural predators of slugs and snails.  The ground beetle is one of them and I go around looking under logs and stones to try to catch as many of these as I can to put onto the allotment.  They need a home to live in such as under planks of wood or ceramic plant pots.  I have put loads of toads on the allotment but I can never get them to stay.  I would love to have both slow worms and hedgehogs on the allotment but sadly I have never had that luxury.

Thrushes used to be the very best snail predator.  They have used paving slabs on the allotment as their anvil to break open snail shells.  Anything that will attract natural predators will help in the control of slugs and snails.

I have built a hedgehog box and put it in the hedge at the bottom of the allotment.  I live in hope.

In the yearly planning of an allotment resistant varieties such as Fly Away carrots, which are resistant to carrot root fly and Clapton cauliflowers, which are resistant to club root can be looked for in the catalogues.

Planning a rotation of vegetables each year reduces the buildup of pest and diseases in particular areas of the allotment.  Brassicas are particularly sensitive to club root but a good rotation of more than a three year cycle will go a long way to prevent its build up in the soil.  I have a six year rotation cycle but, with the new half allotment, I can make this even longer.

Barriers can be used against several different pests.

Chicken wire around peas will help to keep
pigeons from eating the foliage.
Scaffold netting over the brassicas
Scaffold netting will keep both pigeons and cabbage white butterflies away from the brassicas.

Enviromesh over the carrots to keep carrot
root fly away from the plants.   
Bordeaux mixture of lime and copper sulphate can be applied in late June to prevent blight.
Potatoes in late June sprayed with Bordeaux
Nematodes, predators of slugs and snails, can be applied in six week intervals.


I use Nemaslug nematode Phasmarhabditis hermaphrodita worms spraying them only in areas where I know snails and slugs congregate.  While this is not 100% effective, it does seem to have reduced damage and the breeding adults so that there are fewer eggs to overwinter.

While I can understand the agonizing that many of us undergo when attempting to produce food that is grown with as few human made chemicals as possible, we must be reasonable.  The slug and snail pellet ferric phosphate FePO4 is indeed an inorganic chemical.  This means, in chemical terms, that it does not contain carbon.  Confusion comes when we apply the term organic to gardening.  Organic in biology means related to life or organisms.  If we replace the metal iron with the metal calcium in this compound we get a major component of bones -  calcium phosphate, which although making bones is an inorganic chemical.  Does this mean that the strict advocate of organic gardening should not use blood, fish and bone as a fertiliser?  I dont think so.

I would rather not use ferric phosphate as a slug and snail killer because I would rather remove as many slugs as I can by hand - gloved if possible.  There is little evidence about the effect of ferric phosphate on other soil organisms and is probably best avoided if you are trying to be organic.

As the gardener Percy Thrower used to say a tidy garden is a good garden.  If there is no habitat for the molluscs to live in then there will be fewer of them.

If you are going for the hand collection method it is easier if you use traps like upturned flower pots, upturned orange or grapefruit skins or planks of wood.  I have seen people use newspaper soaked in sugar solution and covered with a plank to attract slugs and snails.  These methods may serve to attract slugs and snails but I use them regardless.

Beer traps are also effective and so too is a diluted honey and yeast mix.  There are other recipes such as sugar, flour and yeast or just diluted sugar solution and yeast.

Introducing mychorrhiza when planting may improve the health of plants and healthy plants are more resistant to pests and disease attack.

It is important to keep the allotment tidy and remove all dead, diseased or damaged plant material from the allotment.  Sometimes, for example, leaves infested with aphid can be sprayed with water to remove them but if they are persistent then the leaf can be taken off and composted.

So, many different methods of pest and disease control that can be used without resorting to man made chemical sprays.

However, the best way of keeping plants healthy is to provide them with optimal growing conditions and keeping the allotment very tidy.      

This year's sweet peas.

I have ordered my sweet peas from Roger Parsons Sweet Peas.

2015's  varieties are:

  • White Frills
  • Doreen
  • Gwendoline
  • Yvette Ann - may have to be replaced by another pink variety.
  • Daily Mail
  • Mark Harrod
  • Windsor
  • Joyce Stanton
  • Just Julia
  • Andrew Cavendish
  • Ethyl Grace
  • Jacqueline Ann
  • Bristol
  • Charlie's Angels
  • Oban Bay.  
I will be sowing them in January this year and keeping them in the greenhouse until March when I will plant them out in their permanent positions.  Roger Parsons sells the seeds in packets of ten, so if all the seeds germinate and all the seedlings survive, I will have 150 plants.  I have grown White frills; Gwendoline; Daily Mail; Windsor; Ethyl Grace; Bristol; Charlie's angels and Oban Bay before but the others will be new.  I am concentrating on the blues in 2015 - just for interest.

As I was working today, I have not done too much down the allotment.  The nights are drawing in far too quickly now and, just when you have started to do something, suddenly it is dark.

Dug a little more topsoil out of the trench and sieved it.  Took the subsoil down to the hole by the shed and tipped it.  Dug the topsoil out of the main path, sieved it and put it into the trench to replace the subsoil.  Filled the hole in the path with the subsoil and stones taken out when I made the hot bed.  This subsoil is in the way of the main trench going across the allotment so I will continue to make a new path with it just to get it out of the way.  I reckon that this might take some time because the path is so infested with perennial weeds.

There is an awful amount of mare's tail and bindweed in the path which had to be sieved out.  I did about 2 foot square, one spit deep and it virtually took all the time I had at the allotment to clean out the topsoil.
This is what the allotment looked like
on November 19th 2013
I had dug further down the allotment in 2013 than I have on the new half this year.  The new half allotment is not quite as untidy as the one in the photograph so will be dug quicker with any luck.

I want to plant the currants and rhubarb in their permanent places as soon as possible so I will have to get a move on trenching the new half allotment.  The rhubarb is still growing in the Mount Road allotment so will have to be transported to this allotment during the winter.

So the idea is to improve the soil with the addition of organic matter.  You can either do this by trenching or by mulching, however there is nothing to stop you doing both.

Tuesday, 18 November 2014

Continuing to raise the allotment with trench Hugelkultur (2)

Before continuing with the trench Hugelkultur, the apple sions that have been taken from neighbouring allotments had to be stored away.  These were wrapped in polythene bags and buried in a cool part of the allotment.  A cane with a label on indicated where the sions were buried.
The sions were 'James Grieve'; 'Saturn'; 'Greensleves'; 'Egremont Russet'; and 'Braeburn'.  Not necessarily the ones that I would have chosen but beggars can't be choosers.  These will be used to graft onto the M9 and M26 rootstock.

After this, the new currant bushes were healed in.   Blackcurrant 'Ebony' and 'Ben Connan'; redcurrant 'Rovada' and white currant 'Blanka'.  These will be moved to their permanent positions when the ground has been dug over.

I took about one square metre; one spit deep of subsoil out of the bottom of the trench and used it to make more pathway by the shed.  Carting waterlogged clay subsoil is not my idea of a pleasant activity but it had to be done.
Due to the wet weather, the water table has
risen and water is collecting in the trench.
The subsoil has not been taken out of the trench in the photograph. The cardboard that was taken out with the subsoil was returned to the bottom of the trench. Cardboard does not last very long on the allotment before it decomposes.  I add it to the trenches whenever I have some handy.

As the bottom of the trench was so waterlogged, it was not forked over very well.  I was relying on breaking up the bottom of the trench with the spade when subsoil was being taken out.    I did not stand in the trench as I usually do because I would have sunk in the water clay mix at the bottom.  There were many rhizomes of mare's tail in the subsoil and these were removed as much as possible.

Decaying processed wooden planks were
put at the bottom of the trench. 
The decaying wooden planks were put at the bottom of the trench.  I used planks like this last year when trenching the other part of the allotment and there was no problem with nitrogen depletion. The ends of the planks were very fibrous and broke apart in my hands.  This spongy material will absorb water and release it when the soil is dry.

Covering the planks was a layer of hawthorn and ivy.

Hawthorn and ivy brushwood.
I cut this brushwood from the hedge at the bottom of the allotment using the loppers.  However, there is not much left for the next trench so I will have to search around for more elsewhere on the allotment site.  I threw in some more processed wood too.  There is a plastic catch on the wood at the top of the pile.  I took this off and put it in the rubbish tub to be buried at the back of the shed.  I don't really want any plastic in the growing area trenches and actively remove any that I find.

The brushwood was covered with a six inch layer of woody ash tree shreddings.

Ash tree shreddings
These shreddings were watered with concentrated comfrey liquid before being covered with topsoil sieved from the paths by the shed mixed with a little chicken manure.
Path topsoil added to trench.
The path topsoil was very friable and had a lot of decayed wood shreddings in it.  It should be quite fertile because nothing but mare's tail and bindweed has been growing in it for many years.

Over the topsoil I put a layer of farmyard manure and then covered it with the sieved topsoil from the trench.  This has given me about 18-24 inches of good top soil over the trench Hugelkultur, which will produce some good vegetables.  I am planning to plant ridged cucumbers here next year.

The little greenhouse is slowly sinking into the ground because of the trenching I have done around it.  The glass will have to be taken out and the greenhouse frame raised level again.  However, I will not do this until the topsoil has settled.

It does not seem that I have done much today but I had to cut the hedge back to provide some brushwood; dig out and sieve the path topsoil;  dig out the subsoil and put it into the hole I made in the path and level everything with the rake.

And I want to do this over the whole allotment?  Well I did for the other part of the allotment.

This is where the new currant plants are going to to be planted as a hedge to divide the curbit bed from the brassica bed.  Currants appreciate a deep root run so they will do well in trenched topsoil.