Winter weather getting colder closing down the allotment..

I was the only idiot down the allotment today.  It was very cold.  I went up to finish off digging in the manure into the sweet pea bed.  The soil here is very good now but it needs levelling out .  I have still to put up the supporting posts for the sweet pea canes but this can be done later.  I am going to put cross pieces on the posts so that the canes can be attached vertically rather than sloped.  After some thought, it is better to keep the tops of the plants away from each other because they just grow into each other and this encourages pests and diseases.  Also it is more difficult to take off the side shoots and and tendrils.

There is some thought that you should dig over roughly and leave the weather to break down the clods of soil. Well, I religiously did this year after year until I suddenly realised that the weather was not having any effect on the soil and the person who broke up the clods of soil was me.

If I am going to have to break up the soil, I might as well do it while I am digging rather than later on in the early spring.  So I have broken up the soil with a fork and raked it over to make it fairly level and presentable.  It will have to be done again in the spring but it will not take a lot of time to go over it once or twice more with the rake.

There is a bit of horse manure left on the sweet pea bed band I am going to dig this in where the celery is going to go.  I am going to take out a trench and sieve in horse and pigeon muck. I will plant the celery at the bottom of the trench and keep the trench as damp as I can during the spring and summer.  With any luck I will get some good celery plants.

Rather than start on the top allotment, I decided to go down and tidy the comfrey bed.  I wanted to plant some autumn fruiting raspberries here so I decided to do this too.  It was not the best time to transplant the raspberries because the temperature was about 2^oC.  However, it was either plant now or throw the plants away.  The raspberries were planted with a good dose of mychorrhizal fungi but nothing else.  Although it was very cold, the wind was drying the roots out and I wanted them covered as soon as possible.  


I didn't water them in because the soil was very wet verging on waterlogged.  


Along the side of the comfrey bed I am planting a small 150mm hedge of Locinera nitidia one of the shrubby honey suckles.  I am putting some mychorrhizal fungi on these plants' roots as well.  The theory is that these mychorrhiza will form associations with the Locinera nitidia  and grow out to the comfrey making associations with them as well.  The hyphae will then forage for nutrients from the surrounding soil passing some of them to the comfrey.  As this part of the allotment is at the bottom of the hill, all the nutrients leeching out of the other allotments will pass through this part of my allotment and the fungi will be able to tap into this.  My comfrey will potentially be fed by all the nutrients that other people are putting on their allotments.  Thus  I will get comfrey liquid fertiliser fortified by other allotment holders.  I doubt very much if this will happen but I like to think that it will.   


I then when to straightening the lines of comfrey plants which was quite difficult because they have died right back and I could not find them.  Eventually I found some of the roots and put them in the line.  Any that come up in the wrong place later in the spring will be moved onto the correct line.  


I just threw in the original lines of comfrey so they were all over the place.  The new lines of comfrey just followed the old ones.  They were fairly straight but going a little diagonally across the bed and this was annoying me.  Now they are straight and parallel to the new potato bed.

I have mulched the Vitis vinifera with some of the stones that I took out of the soil.  I have chosen stones that are smooth and about the size of my fist.  It looks just like Ground Force.

A black dustbin has been put over one of the Victoria rhubarb plants.  I have put some horse muck around the bin to warm up the soil around the plant.  I will do the same for as many of the other rhubarb plants as I can.  With any luck I will have some forced rhubarb for the early spring.    The rhubarb is not showing yet.  It really needed this cold snap to prod it into growth.  Unless February is particularly cold, I will expect to see some buds developing fairly soon.

I have ordered the Nemaslug nematodes and they will probably be coming in March.  I will have enough nematodes to cover the whole of the top beds.  I am hoping that they will reduce the population of slugs and snails enough so that I can get some fairly large plants this year.  You can tell where they are at the moment because they are eating the green manure.  All around the edge of the allotment the green manures are stunted and eaten back.  When the beer runs out, I am going to try the sugar water and yeast trap to find out if it is better than beer.

JBA potatoes has just sent an email saying that the seed potatoes will be delayed a little due to the frosts and cold weather.  I am not worried at all because keeping them alive during cold spells like this is quite difficult. I would rather have them later and be able to put them out into the cold greenhouse to chit.

The celery and the tomatoes are growing on now but they are a little drawn.  I will plant them quite deep in three inch pots and see if they develop a little more robustly.  Regardless of the weather, I will still carry on planting seeds through February.

The weather is getting decidedly colder and little can be done when the ground is frozen.  I think that I will be shutting the allotment down for the next week or so.  In other words, I will be keeping in the warm until the weather decides to get a little warmer.

November digging the new potato bed.

I have put all the comfrey, sweet cicely and the nettles in the bins and they are not very likely to produce any more tops until next year.  The comfrey bins are nearly full of comfrey liquid and I am going to run out of bins to put it into soon.  I will put some on the leeks to see if I can get them to grow a little quicker but this is the only place that I think that it can be used at the moment.

I am triple digging the old strawberry bed at the moment. This is the replacement soil that the council put onto the allotment because the other soil was contaminated by some foul chemical.  They only did the bottom area of the allotment but the soil was, and still is, not very good.  It is mainly a sandy clay with the emphasis on the clay part.  However, this is not the most irritating thing about this new soil.  It is also full of boulders  and stones.  So, while it is being triple dug, it is also being sieved.

I am using Fred's old bread basket to sieve with because it is ideal for sieving out boulders.  I can easily dig down one spit because the top soil is fairly open and friable.  However, the subsoil is just like rock and a fork is needed to penetrate the concrete like soil.  This is not like the soil on the rest of the allotment.  I can go down about a metre on the rest of the allotment and even then the soil is fairly open and friable.

So, the soil is being sieved into the wheel barrow and at the same time horse muck is being added and sieved with it.  An amazing amount of stone is being taken out and it could lead to a lowering of soil level.  I have decided to replace the stones with turfs from the bins by the entrance gates.  It is more soil than turfs but this is of no consequence because I need some top soil to improve this concrete,granite like soil.  The remains of the home made compost is being put at the bottom of the trench with the old strawberries and this is covered with the turfs and then the sieved subsoil goes on next with the sieved top soil going on top.

I have to be careful when I am sieving not to sieve out large pieces of inoculated charcoal.  The bits that I am finding in the bread basket sieve are taken out and crushed with a bull hammer so that I can mix it in with the sieved soil easily.  I am also using the bull hammer to crush some of the stone.

My theory is that a lot of soil nutrients come from the bed rock through weathering.  Although turning over the soil is a kind of weathering and will lead to some breakdown of stones and pebbles, if I crush stone with the bull hammer maybe this will help to add some nutrients to the soil as well.   If it doesn't then I haven't wasted my time because the crushed stone is mixed in with the sieved soil and this will help keep the soil open and easily drained.  I might use some of the stone that I have removed and put by the car park to crush and put back on the soil.

I will apologise now for the overuse of Latin names but I am doing the Royal Horticultural Society's level 2 course and I need to learn a load of Latin names of plants.  So whenever I am writing about the plants I will use the Latin names.

Looked at the Lathyrus odoratus (sweet peas) and some of them are germinating already.  It just goes to show that chipping or sanding the seed is not necessary. I think that this myth is perpetuated by people that do not grow Lathyrus odoratus  and have never tried to germinate the seed.

The Ribes grossularia 'Xenia'  (Gooseberry) and the Rubus fruticosus (blackberry - not sure of the cultivar at the moment) cuttings seem to be established and growing on.  The Rheum rhaponticum 'Timperley Early' has started to throw out leaves already.  I am not sure that this is what I want it to do at the moment.  I know it is an early cultivar but not this early.

The winter flowering Cyclamen persicum spp. have just regrown their leaves and are nearly ready to go back into the house for a Christmas display.

More thoughts on Terra preta soils.

I am attempting to create a Terra preta type soil using lump barbecue charcoal.  (Have a look at the links on the right to see the Terra preta film.)

This type of very fertile soil has been found in South America and has been made by people over thousands of years using charcoal as a soil amendment.  The evidence that I originally read was that charcoal reduced the fertility of the soil when it was initially added to the soil.  This discouraged me from doing experimenting on my allotment.  However, after reading around the subject and talking to people on various websites such as Allotments.uk I developed the hypothesis that an "inoculated" charcoal may be able to be used as a beneficial soil amendment to produce  a sustainably fertile soil.

Some people are still trying to develop an inoculated charcoal that is very similar to that found the South American Terra preta.  My reasoning was that this seemed to be over complicated because if the charcoal could be amended by Amazonian nutrients then it should be able to be inoculated with nutrients originating in my local area.

I am experimenting with using comfrey, nettle and sweet cicely liquid fortified with worm bin liquid.

Inoculated charcoal is charcoal that has been marinaded in nutrients.  Charcoal has some remarkable properties that allow it to absorb or adsorb chemicals within its labyrinthine structure.  We can use this property to enable us to deliver nutrients to the soil in a form that might not readily leach away.

I would conjecture that the charcoal acts as a kind of buffering mechanism that allows nutrients to diffuse into the soil when there is a low concentration of them while adsorbing them when there is an excess.

The structure of charcoal also gives a relatively safe place for beneficial bacteria and fungi to live adding more nutrients to the soil.

Research has found that Terra preta soils also contain mychorrhizal fungi which form a symbiotic relationship with plants.  The charcoal could give these fungi a source of nutrient that can be transferred to plants and also a  protected environment for their spores.

Now all of this is complete conjecture because research in this area is in its infancy.  We are trying to follow in the footsteps of ancient Amazonian peoples and it is difficult.

I have had impressive results this year after adding charcoal to the soil.  Whether this is due to the charcoal or to some other factor this year, I don't know.  We are attempting to replicate a soil that has developed in the Amazonian rain forests  areas.  There is no evidence that this can be replicated in places like England.

I would like to think that I have not wasted quite a lot of money buying charcoal and that it does have some beneficial effect on the fertility of the soil.  What worries me is that there is not a rush to add charcoal to the soil by farmers and market gardeners.  Is this because the data is inconclusive or for some other reason such as the cost effectiveness of charcoal.

Now as a warning, I need to emphasise that it is the genuine lump wood charcoal that should be used not the briquets.  Charcoal briquets are made with cement and will alter the pH of the soil significantly.  Charcoal itself is alkaline so any further raising of the pH will significantly change the character of the soil.


Is adding charcoal to the soil any better than just burying unburnt brush and logs?  Hugelkultur raised bed systems, which the South Americans also developed, would suggest that there is little difference.  Both are good ways in which to add large quantities of carbon to the soil.  Is the quantity of carbon in the soil significant in raising its fertility?

Although plants need relatively large amounts of carbon dioxide and water to produce their food, the amount of other nutrients they require is very small.

Anything added to the soil that will help to retain moisture will be beneficial to plants.  There is evidence that charcoal helps to retain moisture in the soil.  Together with water retention there is also a benefit in that addition of long lasting carbon will help with drainage of the soil.

I would conjecture that there is an overall benefit of adding charcoal to the soil and this is similar to adding unburnt organic matter to the soil.

Inoculated charcoal Terra preta soil

The judges for the allotment competition came back to see my allotment again today.  I think that they were interested in the sweet peas but did not really look at anything else.

They were asking what was put on the soil to augment it and I said horse muck, inoculated charcoal, comfrey liquid and mychorrhizal fungi.  They could not believe that such a productive allotment could be sustained with so little input of fertiliser.

Most soils will have ample nutrients for plant growth without a great deal of augmentation, although whether these nutrients are readily available to the plant is another question.  Making the nutrients available is the work of the mychorrhizal fungi.

Nitrogen input into the soil comes from the legumes growing on the allotment.  The allotment is producing a remarkable amount of produce now and the plants are growing particularly big.  Is this due to the charcoal experiment?

Inoculated charcoal has been used throughout the allotment during the planting season.  It certainly seems to have helped the vegetables grow well.  Ordinary lump charcoal for barbecues was used.  It was put into a dust bin and comfrey liquid poured over the top of it.  The charcoal marinaded in the comfrey liquid for several months during the winter. In the spring the charcoal was crushed with a bull hammer and put into the planting holes of the vegetables.  The hypothesis is that the charcoal adsorbs and absorbs nutrient from the comfrey liquid so that it becomes saturated with it.

When it is added to the soil it acts as a type of buffer; releasing nutrient when there is a lack of them but absorbing or adsorbing them when there is a surplus.

Another suggestion is that mychorrhizal fungi can find nutrients in the charcoal and transport them to the plant easily.  So they are added to the planting hole as well.
Now it has been said before that there is plenty of mychorrhizal fungi in the soil all ready.  However, I think that we destroy these symbiotic relationships when we disturb the ground for digging and cropping.  Therefore adding them to the allotment will only help the plants to grow.