Do potatoes need a concentrated NPK fertiliser?

I have to keep reminding myself of this: N - Nitrogen: promotes the growth of leaves and vegetation P - Phosphorous: promotes root growth K - Potassium: promotes flower and fruit growth I know that the biochemistry is much more complicated than this but this is good enough for me. The Marshalls's potato fertiliser is N:P:K 15:21:24.5 which is massive and I don't know why potatoes would need so much potassium. Whatever, I use comfrey for potatoes and this has a higher ratio of potassium, but nothing like the Marshalls's fertiliser. Comfrey's percentage NPK is 0.74:0.24:1.19 nowhere near the Marshalls's fertiliser. Relative to the amount of carbon dioxide and water that the plants need to produce sugars, the amounts of N:P:K that they require is tiny. I would question the necessity for such high ratios. It is remarkable how the amounts of these elements in plants mimic the amounts in the soil. There is some evidence that excessive nitrogen in food is not a good thing. I like to put quite a lot of animal manure on the potatoes and this year it was mixed in well with tree leaves. Apart from this, I am sticking to home made compost, comfrey tea and nettle tea to fertilise my veg. Have a look at what my potatoes are like now in May with only comfrey, horse manure and leaves added to the soil.  Kestrel potatoes at the end of May Kestrel potatoes in June

Using the 3 foot by 2 foot paving slabs.

I unwrapped the tomato seed pot from its plastic bag today to be pleasantly surprised to find that the seed had germinated. Pleasing as this might be; it is only the beginning and I will have to try to keep them alive now until they can be safely put out into the greenhouse or in pots at the allotment.  Not bad for seed given to me. 

I like freebees. 

The great thing about having early plants is that you get a longer cropping season. 

I will leave the seedlings in their pot until they get their second leaves and then prick them out into 3 inch pots.  They will stay in the pots until they are about 6-8 inches tall.   

The Ailsa Craig onion seedlings are doing well in the cold greenhouse.  They will be pricked out in a couple of weeks’ time.  They will be fine in the seed tray for a while.  The Bedfordshire Champion onion seed has not germinated very well.  I don’t know how old it was but it was given to me so I cannot be too disgruntled.

After digging over the potato bed and replacing the curbing with big 3 foot x 2 foot paving slabs, I decided to do all the niggling jobs that you leave because they are not priorities.  The bottom path that leads to the water butt was not really finished off because I ran out of paving slabs.  I decided to use another of the 3 foot x 2 foot slabs to finish off the path.  They are big ugly pieces of concrete and they will break your leg if one falls on you.  Phil my good friend had left them on the allotment.  Again, they were free so I could not turn them away particularly as I had asked Phil if he had got some.  Well, I smoothed the ground well with the rake and made sure that the slab would fit into the area I wanted.  Although I have a very useful trolley that works on the soft ground of the allotment, I decided to walk the slab up to the path.  

 

Luckily, I got it there in one piece – me I mean not the slab.  I dropped the slab into the space I made for it and as far as I am concerned it will stay there for as long as I have the allotment.  A gap of about 1 foot was left and I filled this with a small paving slab.  

Last, but by no means least, I needed to finish off the bottom roots bed curbing.  Now that I have these big 3 foot beggars I might as well use them up to finish the curbing here as well.  

I planted the grape here because the soil was the poorest on the allotment.  The trouble is I did not measure it quite right and it was about 1 foot out of alignment.  Also, if I put the curbing along this side of the bed, I will have to raise the level of the soil slightly.  I did not want to move the grape especially at this time of the year so eventually I made the compromise of putting a square of curbing paving stones around it to keep the soil back from around the grape’s stem ( at the original level of the bed) while allowing me to increase the soil level to the tops of the buried paving slabs everywhere else.  

We have had some quite blowy weather recently and it blew over the trellising that I had put up for the grape.  I needed to take it out to put the curbing in but I needed to make a decision about whether to put it back afterwards.  Having taken down two of my compost bins to give me space for the new shed, I still needed to reconstruct them somewhere else.  To kill two birds with one stone, I decided to construct the bins next to the curbing so that one of the pallet sides would be next to the grape.  I could use the side of the bin to grow the grape up.  

Now I don’t know how many slabs my mate Phil left on the allotment for me but there were plenty to make a paved bottom for the compost bins.  This time, though, I got the trolley out to move the slabs.  I am not sure whether it would be frowned upon to have a concrete slab base for a compost heap but I know from experience it is very much easier to empty with one in.  Before I started, I began to think that if I made the compost bins higher than the rest of the comfrey bed then any leachates from the compost will naturally flow into the soil in which the comfrey is growing.  This bed is already at the bottom of the allotment site and all the runoff from quite a large area flows through the comfrey soil.  

 

The theory is that the comfrey is utilizing any leached nutrients from the rest of the allotment site and now could have the leachates from the compost as well.  Notice all relationship to proper compost bin construction has now gone completely out of the window.

Not wanting to waste any of the soil – even though it was the very poor stony soil that the council used to replace the contaminated soil, I dug down one spit and, leaving the soil on one side, filled the hole with stone from the stone pile.  I put some of the soil back again to level the ground and this had the effect of raising the concrete slabs about 3 or 4 inches above the surrounding area.  That was enough for me. 

The slabs were placed on top of that and the pallets were wired together to make a 4 foot square compost bin.  I did not wire in the front pallet because I wanted to store the comfrey charcoal dustbins on the slabs.   This has tidied up this corner of the allotment very well. 

 

I still have enough slabs and pallets to make another 4 foot square compost bin and this will butt right up to the other one.  I will raise this one up too.  

While I was constructing the compost bins, I had to take out the comfrey that was growing in this area.  I just put it on one side and I will replant it when I have finished making the compost bins.  Comfrey is tough as old boots so leaving the roots exposed like this will not hurt it very much.  It is only the wild comfrey Symphytum Officinale and I can easily replace any that die from waste areas around the allotment.  Someone might be kind and let me have some of their Russian comfrey if I get around to asking them.  The comfrey rows are not parallel to the curbing of the roots bed so I will move them all when I dig over this bed. 

The soil here is thick clay and even the cow manure I packed into it does not seem to have made much of a difference.  I am not looking forward to digging in this area.  However, I have been walking all over it and it is now very compacted so I cannot avoid it.  

I will make a path alongside the other compost bins to the new shed to use up some more of the slabs and to keep me from treading between the comfrey plants.  This will finish off the whole of the allotment in the slab department and anyone who wants the excess slabs can have them.

Should we be using aspirin as a pesticide?

Organic gardeners, like myself, must try to remember that everything is made out of chemicals including ourselves and the vegetables we eat.  Some chemicals are more dangerous than others.  This includes “natural” chemicals like belladonna (atropine) and digitalis.  A great number of medicines started their lives as plant extracts like these.   Salicylic acid has been found in most plants and was first extracted from the bark of a willow.  Aspirin (acetylsalicylic acid) is made from salicylic acid. 

Some scientists asked the question why do plants produce this chemical and it turns out to be part of the plants immune system; the way that it combats disease and pests.  There is a lot more information here:

  http://www.news.cornell.edu/releases/Dec03/take_two_aspirin.hrs.html

This is not the only immune system that has been discovered in plants; however it is the one that amateur gardeners could use to help them in their garden or allotment. 

http://www.sciencedaily.com/releases/2007/10/071004143125.htm

What about trying aspirin? I have tried it on virtually all my allotment vegetables, however it seems to be more effective when sprayed on seedlings.  

Now that Derris and Pyrethrum have been proscribed in the UK, there is little for the amateur gardener to use against pests and diseases.  Picking off pests might be alright for gardens and allotments but whether this is viable for farms I would question.  Maybe aspirin might be a way of preventing pest damage to crops that is a little gentler to the Earth than artificial, petrochemical pesticides. 

There is much that is unknown about the use of aspirin and there may be unforeseen damage to insects other than those attacking vegetables.  Yet, I have been spraying with aspirin since March 2008 and I have seen lots of ladybirds on my vegetables.
The most noticeable affect that I have seen is the reduction of whitefly on my winter brassicas. It almost encourages me to start to grow kale again.

The two unknowns about aspirin application to plants are the dosage and the timing. I have used 2 tablets in 10 litres (2 gallons) of water. I only sprayed seedlings once but the veg. about once a month.   I have used dissolvable aspirin in these experiments.  I know that other people are using willow water made by marinating fresh cut willow branches in water.  As some organic gardeners object to the use of synthetic aspirin, willow, a good source of salicylic acid, water could be used instead.  So we could argue that spraying with aspirin is similar to spraying with nettle or comfrey extract as a pesticide.
A more effective way of extracting salicylic acid from willow bark is to make it into a tea using boiling water. 

Rather than using the organic label, I would rather the: "natural" label. Maybe that is just as difficult to define, but I mean by it that I am using nematodes, fungi and bacteria to combat diseases and pests. And I use a barrier rather than chemicals that are not usually found in nature. Aspirin, as I said at the beginning, is found in most plants.  I would suggest that it may be one of the more benign of the chemicals that plants produce and therefore a chemical that we can use to advantage on the allotment. 

Comfrey tea

I have said in several of the previous posts that I use comfrey, sweet cicerly and  nettle teas to inoculate charcoal.  I also use them as liquid fertilizers. 

I have grown comfrey (Symphytum officinale) for about 30 years now.  It has a beautiful pink purple flower and large dark green leaves.  It can grow up to 1.5m tall and is rather a thug in the vegetable plot if you allow it to be.  I have five 25ft rows of it.

Comfrey bed 

My plants are not the sterile  Bocking 14 and they produce seeds prolifically.  They will spread.  Their roots are very thick and robust and you can use them to propagate new plants.  They are, indeed, very good ground cover plants because little will grow under them particularly if you grow them closely.  

Neat comfrey coming out of the butt.
This butt does not have a tap

Whenever I feel in the mood I cut down the comfrey and put it into a butt (a water barrel) with a tap at the bottom.  The comfrey rots down to a black liquid and that can be drained out of the barrel.  Some people cover the comfrey in water but it is unnecessary.  The liquid is relatively high in potash (Potassium) so it is good for fruit and flowers.  Its percentage NPK is 0.74:0.24:1.19 for the Bocking 14 comfrey

(http://organicgarden.org.uk/gardening/comfrey) 

which compares very favorably with commercial tomato liquid fertilizers. 

However, it costs nothing!

What goes into the barrel stays in the barrel.  It will all rot down regardless of how tall the comfrey grows.  It does get coarser as it gets bigger and takes a little bit longer to break down in the barrel but it still forms the black liquid.  Now, you might think that the decaying comfrey would block up the tap at the bottom of the butt but it decomposes so quickly that it rarely if ever blocks the tap. 

I kept a large bottle of comfrey liquid for about 3 years and it still seemed to be alright. I keep my comfrey for about 6 months to a year in the butt but I keep topping it up as I crop the comfrey. It lasts over the winter as well. 

Nowadays I bury most of the allotment undiseased waste in the comfrey bed and let the comfrey recycle it for me. It gets a dose of manure or lawn mowings along the rows when I have nowhere else to store them.

The stinging nettle (Urtica dioica) and Sweet Cicerly (Myrrhis odorata) also make valuable liquid fertilizers.  Ref: “Ear to the Ground” by Ken Thompson.

Both worm tea and comfrey tea seem to make tomatoes grow.  I don’t know the NPK ratio for worm tea but I don’t think that it would be too different from comfrey tea.  

Comfrey does smell when it is rotting down and that is why I put it in a covered water butt.  I do not put water with it because that makes it smell even worse.  If you are constantly using it, like I am, then the smell does not seem to be so bad.  I use it on all the vegetables although things like beans and peas together with tomatoes and pumpkins seem to thrive on it.  

Hunts (see comment below) said that he found maggots in the dried comfrey liquid.  I reckon that these were rat tailed maggots. They are larvae of one of the hoverflies such as Eristalis tenax.  The larvae are one of the few that will live in very polluted water.  While some hoverfly larvae feed on aphids, Eristalis tenax larvae probably live off bacteria or other microorganisms living in the polluted water.  

So how to make comfrey tea that will not go ‘off’.  I think that Hunts’ went off because all the water in it evaporated away.  So,  run it into old orange squash bottles –the large ones with a handle at the top.  Screw on the top and this will prevent the adult hover flies from reaching the liquid.  I have kept comfrey liquid for some time like this.  You can then dilute it down however you want.  I dilute  it down like Tomorite plant food. 

Nowadays, I put the comfrey liquid into a lidded dustbin full of charcoal so that the marinating charcoal soaks the tea up and I can put it onto the soil in a more sustainable form.  I suggest, and there is very little evidence I can quote on this, that the comfrey liquid nutrients will not be leached out of the soil quite so readily in this form.  This is one of the main principles behind the development of a method of creating Terra preta type soils in England's temperate climate. 

As Mikey says in the comments below, the comfrey leaves can be put into the worm bin as in the photograph below.  

However, I would fill this little bin up several times over with the amount of comfrey leaves that I produce.  So the large bins are also brought into service.  In addition to comfrey leaves, I put most of my pernicious weeds in this worm bin.  Bindweed Convolvulus sepium  and horse tail Equisetum arvense ( arvense meaning of the field) are the two main weeds added to the bin.  Comfrey leaves or not, the bin produces copious amounts of black tea like liquid which get mixed with the comfrey liquid manure.  In the front of the worm bin is an area of nettles Urtica dioica  which is also added to the worm bin and the comfrey bins.  It is all grist to the mill.  

Took Some Photographs of the Allotment Today

The allotment always looks untidy in January.

The ground was frosted and covered with a sprinkling of snow so I did not move any more of the blackcurrants.  I got some leaves and lawn mowings and filled up one of my bins with them. I put weed turfs on top of that.         

The bins are made from old pallets which are wired together with fencing wire.  I took two bins down so that I could putup my new shed  but I am going to make some new bins at the end of the comfrey bed.


There is a lot said about making compost.  I find that heaping anything that was once alive into a big pile and leaving for six months to a year breaks down into fairly good compost and even if it doesn't it can be buried relatively deeply and left to its own devices. I am not one for fussing about compost. 

This is one of my charcoal bins with charcoal marinating in comfrey and worm tea. There is also some sugar molasses, and some blood fish and bone in this bin.  I have used almost all of the charcoal in the other bin.  The lid is kept on so that the bins do not fill with rain water and overflow.

This is my comfrey bed.  The plants don't look too good at the moment but in the summer they can grow up to 1.5 metres.  The comfrey is harvested and put into the big green bins. 
Comfrey is as tough as old boots.  It will certainly come back in the spring.  Mine has died down and is difficult to make out at the moment.  I tried digging between the rows and started to dig up roots.  Not to worry though because I just planted them again.  They might not come but I have sufficient anyway. 
A bit of frost and snow will not hurt comfrey.



As the comfrey rots down, I run off the liquid into a small tub and put it into the charcoal dustbin. It looks a bit untidy because I had to move the dustbins.  Someone had pushed them over while I was on holiday but I have still been able to refil one of them with comfrey tea etc.

I use a water butt to make comfrey tea but I am not adding water at the moment. I have 5 rows of comfrey and two rows of nettles - grown properly with weeding and hoeing. I am now using sweet cicerly as well. It all makes a very good liquid fertilizer. I water it down in the watering can but it does not seem to affect the plants adversely if you use quite a concentrated liquid. I think that you are wasting it if you use it too concentrated. Looks just like Tomorite to me.

They say that nettles are high in nitrogen and comfrey is high in potassium. Compared with what though? I think we are talking about very small amounts of nutrient but that is all that most vegetables seem to need. Nettle and Comfrey have more nutrient than farmyard manure but farmyard manure has very little nutrient  so there does not need to be much more to be better. I think that the adding of both comfrey liquid and farmyard manure to the soil have greater effects than just adding artificial nutrient. They encourage soil organisms, which may form symbiotic associations with plant roots or at least provide further nutrients or nutrients in a form that the plants can use.

 5 rows of strawberries.  This half of the strawberry bed has marinaded charcoal and the other half of the bed does not.  I put the charcoal in the planting holes.  We shall see if Terra preta works with strawberries.
Several rows of broad beans behind the strawberries seem to be surviving the very cold weather.  The strawberries were planted during September and the broad beans during October 2010.


This is where the Kestrel potatoes are going this year.  The horse manure will be spread about and dug in as I plant the potatoes.  Half the potatoes will have inoculated charcoal and half will not.  I will also plant some earlies as well. There are still two half rows of carrots, two and a half rows of parsnips and several beetroot still surviving in this bed.  I will need  to clear it by March this year. 


This is the onion bed.  The garlic is in already and showing through. I have not dug this area because it had potatoes on last year.  I have just levelled it out a little so that I can plant the onions and leeks.  I will be covering both the onions and the leeks either with cloches or enviromesh to protect them from the leek miner fly, Phytomyza gymnostoma.  This fly was first detected in Wolverhampton and I have had it on my allotment since 2000 if not earlier.  I thought it was onion eel worm but I can grow very good leeks if I cover them which indicates this is an air borne rather than a soil borne infestation.  It comes to something when you have to cover leeks and onions.

I think that I added a little bit too much brush wood to this soil  It is three spits down though. I will be planting the cordon sweet peas and the runner beans in this bed. 








This will be the brassicae bed this year. I am attempting to move the black currant bushes to a more convenient position but it keeps on snowing.  I will endeavour to persevere. I am planting the blackcurrants with inoculated charcoal and mychorrhizal fungi. I don't really want to, however, I will plant half with charcoal and half without just to see if charcoal affects the cropping of blackcurrants.

The purple sprouting broccolli has been knocked about by the snow and frost but it is very hardy and I expect it to recover.  There are some winter cauliflowers behind them that are surviving well.  They are covered with netting to keep the pigeons off them.  Sprouts are behing them.

I am surprised that the bay tree has survived but it gets hardier the older it gets. 

I have picked a lot of the brussel sprouts.  The variety I have left were much smaller than the Trafalgar so I will not plant them this year. Needless to say I have forgotten what they are called. 

Early January Jobs

I went to the garden centre to have a look to see what onion varieties they  had in their seeds.  I think that I am going to stick to the traditional  Ailsa Craig but I didn't get any so I can change my mind if I want.
I already have some peat free potting compost so I can plant straight away when I get them.  I will probably germinate them inside because the greenhouse is not heated.  I will put the tray into a transparent plastic bag and leave it near the window.  Now it is my understanding, although I don't know where I read it, that onions can stand quite low temperatures once they have germinated.  So, I am going to put them out in the greenhouse and hope for the best.

We have been having a very cold winter here in the UK and temperatures in my garden have gone down to -16^oC several times.  This means that I have lost a lot of my stored potatoes.  I store them in large paper bags and cardboard boxes.  Once they freeze they go soft and begin rotting.  I might still have enough to last until the spring but I have lost about half of them.  I was not expecting the weather to be so severe this year.

Over the years I have forgotten how bad winters can get.  Each year the winters have been warmer and storing vegetables has become much easier.  Still nothing goes to waste and they were put onto the compost heap.

In the 1950s and 1960s I put my potatoes in a clamp.  This is where you have a heap of potatoes or root crops protected from the weather that you are going to eat during the winter.

Its been a long time since I put potatoes in a clamp and it is only worth it if you have a great many potatoes.
You will need 2 cm layer of gravel on the driest part of your allotment. Onto this you put the potatoes to make a pile that goes up to a point at the top. My father and I left them like this for a couple of days to dry off. Then we covered them in about 10 cm of straw. Finally we put about 4cm of soil over the straw. The soil has to be patted down carefully to make the sides of the heap smooth so that rain will run off it and not into the pile.

I do not remember whether there was any slug damage but you are storing during the coldest months when slugs and snails are not so active. If you make sure the potatoes are fairly clean then I doubt if you will get much damage.

I went up to the allotment yesterday with the intention of moving the black currant bushes. Needless to say I didn’t move them.  

Some free horse manure had been delivered to the allotment site so I decided to get some more to put onto this year’s potato bed.  Most of it had been taken so I was reduced to raking it up into piles and shoveling the piles into the barrow.  I got about 4 barrow loads of scrapings and it is all grist to the mill.  

I also emptied the comfrey tea out of the comfrey bin and put it in the charcoal bin so that the charcoal would take it up. Or that’s the theory anyway.  I also emptied the tea out of the worm bin and added some more kitchen scraps. I have put the worm bin in the bottom shed just to give the worms a little more protection.  This went into the charcoal bin too.  

Then it was starting to get dark.  I had intended to measure all the beds so that I could make a plan of the allotment and start to see what I needed in the way of seeds.  I got the whole allotment measured out but I realised that after a lot of hard work, the beds are not all the same size as I wanted them to be.  They are very different.  
 I doubt if I will change the paths at all now because I have made them part of my drainage system.  

The spring was just infront of the shed.  I removed all the top soil from the path and from under the shed and replaced it with stones.  Covered the stone with a little subsoil and then laid the slabs. 

I thought that the topsoil under the paths was just going to waste.  So I dug it out and put the soil onto the beds.  Then all the stone that I removed from the allotment and could glean from the allotment site, I used to fill the trenches.  I put a little subsoil on top of the stones to level the ground to put the slabs on.  This means that all my paths are soak aways.  This was necessary because I have two springs on the allotment that were flowing for most of the year. Now the water runs underneath the subsoil and into the soak aways and then into the drainage pipe that runs down the side of the allotment.  There was no water on the allotment or down the trackway yesterday, until the carpark.  First time ever I think.
Reluctantly, I came home.

Sweet peas

I usually sow sweet pea seeds in the autumn.  October seems to be the best month.  I do not nick, sand or any other way mutilate the seed.   I find that they germinate well without damaging the outer shell of the seed.  I think that if the seed do not germinate, it is more to do with the viability of the seed rather than the thickness of the seeds outer coat. The pots are left in the greenhouse overwinter.  It is a cold greenhouse with no heating at all. 

I sow the seed in individual 3 inch pots and label them carefully. I use New Horizons peat free compost to plant them in.

When the seedlings have grown their second or third leaf, I pinch out the growing tip to encourage side shoots. The strongest side shoot is left while all the others are removed. Some growers leave two side shoots. From what I have seen of other sweet pea growers, this is quite an important thing to do if you are growing exhibition standard cordon sweet peas.

In the past I have taken out a trench and put in well rotted compost or manure, however now the soil is very fertile on the allotment I don't necessarily do this any more.

I use canes to grow the sweet peas up and make a line of canes in a similar way to runner bean rows.

I plant sweetpeas out fairly early - end of March or the beginning of April. When I planted the sweet pea seedlings I included both inoculated charcoal and mychorrhizal fungi in the planting hole.

I grow them as cordons i.e I take off all side shoots and tendrils and tie them to a cane. It is really the only way to get large flowers. The other secret, and please don't tell anyone else, is to feed the sweetpeas with comfrey liquid. They love it.
I am experimenting with using charcoal inoculated with comfrey tea and that had even better results for me.  We will be experimenting again in the spring.

The leaf is the food factory for the sweet pea. If you take off the leaves it will begin to starve to death. The tendrils grow out of the leaf and these can be taken off - not the leaves. If you are cordon growing them then you will need to take off the tendrils and the side shoots. They are then grown up strings or canes to support them. I am going to put some pictures of my sweet peas on the blog later. You will also have to tie them onto the canes with wire because you have taken off their natural climbing apparatus. If you do this carefully and feed them with comfrey liquid you will get large exhibition flowers.

If you just want flowers for the house then let them grow naturally and provide them with netting to climb up themselves.  They will not grow as large as cordon sweet peas either in height or size of flowers.

Comfrey, Nettle and Sweet Cicely Tea

I have five rows of comfrey and two rows of nettles grown properly with weeding and hoeing.  I am also using sweet cicely which also makes a good liquid fertilizer.  I harvest them by cutting near to the base of the plant and take off all the leaves.  They are then put into one of two very large butts I have.  I do not add any water, although I have made comfrey tea using water in the past.   I leave the comfrey, nettles and sweet cicely leaves in the butt for about a month or two.  However, I keep draining off the tea using taps at the bottom of the butts and putting into the dustbins with charcoal. 

The tea looks just like Tomorite to me.  I keep filling my butt up with leaves throughout the year as they rot down. I try not let the plants get too big or flower. I harvest the leaves about 5 times a year putting the leaves in the same butt unless it is full. I have other butts that I can put comfrey in if I have too much. There is a tap at the bottom of the comfrey butt and I use this to put some in the watering can each time I water things. It is relatively high in potash (K) - good for flowers and fruit. So, yes you can keep adding leaves to the butt if you want to.

They say that nettles are high in nitrogen and comfrey is high in potassium. Compared with what though? I think we are talking about very small amounts of nutrient but that is all that most vegetables seem to need. Nettle and Comfrey have more nutrient than farmyard manure but farmyard manure has very little nutrient in, so it does not need much more to be better. 

Ken Thompson in his book "An Ear to the Ground"  says that Russian Comfrey Symphytum x uplandicum  is rich in all three main mineral nutrients, nitrogen, phosphorus and potassium but it is not unique in this.  "Some plants can do just as well, maybe even a little better  including: chickweed (Stellaria media),  nettle  (Urtica dioica), sweet cicely (Myrrhis ororata), fat hen  (Chenopodium album), goose grass (Galium aparine), and hedge garlic (Alliaria petiolata).  So I chuck some of these into the butts as well. 

I think that the adding of both comfrey liquid and farmyard manure have greater effects than just adding nutrient to the soil. They encourage soil organisms which may form symbiotic associations with plant roots or at least provide further nutrients or nutrients in a form that the plants can use.

Healthy soils with lots of dead plant matter, humus and microorganisms grow good plants.

Comfrey is as tough as old boots. It will certainly come back in the spring. Mine has died completely back and is difficult to make out at the moment. I tried digging between the rows and started to dig up roots. Not to worry though because I just planted them again. They might not come but I have sufficient anyway.

A bit of frost and snow will not hurt comfrey.

Terra Preta on a cold December day.

Although I am going to go through what is known about these black earths, I think that it cannot be decided how useful this will be for amateur gardeners until we have tried it for ourselves.  This is what several of us are doing at allotments.uk.

Could the research on Amazonian black earths be applied to British soils to increase their fertility?  Research shows large areas of fertile black earths in otherwise very poor rain forest soils.  The fertility of these soils seems to be associated with charcoal added to the soil over thousands of years by indigenous South American civilizations.  This could have been done purposefully or coincidentally when adding midden contents to fertilize fields. Regardless of their motivation, it seems that this has produced a remarkable soil with some strange characteristics. 
It seems that regardless of its use it remains fertile for generations even when these fields were reclaimed by the rain forest.

Ignoring the weeds, this end of the pea rows did not get any inoculated charcoal. 

 This is the end that got the inoculated charcoal. Not the best peas in the world because they were on relatively infertile soil.

However, when scientists add charcoal to soil there is a noticeable reduction in fertility. This is cited as a reason for not developing a slow acting soil amendment from a charcoal base.  How could such a relatively inert substance, which does not degrade substantially over hundreds of years, reduce fertility?

There is some suggestion that charcoal adsorbs or absorbs nutrients in the soil.  It certainly has the capacity to do this having an intricate structure of many small channels giving it an extremely large surface area.

So nutrients may well have a tendency to adhere to the large surface area.  As there is a depletion of nutrients in surrounding areas of soil when charcoal is added to the soil, maybe adding nutrients to charcoal before putting it on soil might mitigate any adsorption or absorption problems that adding "neat" charcoal might produce. 

This could produce a slow nutrient release system.  Affinity of the charcoal for nutrients depends on the condition and type of soil it is in, but I would suggest that this would be a buffering mechanism.  It would adsorb nutrients when they were in surplus but as concentration decreases the charcoal will lose nutrient by a diffusion process maintaining equilibrium with the surrounding soil.
What kind of nutrients could amateur gardeners inoculate the charcoal with to give the maximum long lasting effect on the fertility of their soil?
Several different methods and recipes have been suggested; however I will only give you the method and nutrients that I use personally.  My charcoal, which is just barbecue lump charcoal, is marinated in:

·         Chamomile tea

·         Nettle tea

·         Sweet Cicely tea

·         Worm tea

·         Sugar

·         Blood, fish and bone meal.

The mixture is housed in an old plastic dustbin and left for at least two months.  After this time the charcoal is removed, allowed to dry and then crushed with a bull hammer into pieces no more than 1 cm³.  This gives the charcoal a larger surface area and makes it easier to add to the soil.  I have used bigger lumps but they are cast to the top of the soil continuously by the frost rather than being incorporated within the top 15 cm of the soil. 

There are large numbers of micro pores formed from the xylem and phloem structures within the charred wood and both soil bacteria and fungi could find a habitat in these pores free of predators.

The importance of the micro fauna and flora of the soil cannot be overestimated especially when considering the number of symbiotic or mutually beneficial, relationships there are between micro organisms and crop plants.   There are some tentative indications that mychorrhizal fungi associations with crop plants are encouraged by the addition of charcoal to the soil. Mychorrhizal associations with plants enable them to obtain nutrients from a wider volume of soil than otherwise would be the case, the plant giving the fungi sugars in return. 

My contention is that cultivation disrupts this association and kills off mychorrhiza fungi through cropping, digging and forking.  Adding these fungi to the charcoal may help to replace them in the soil.  A number of scientists suggest that the soil is abundant in spores of these fungi and that adding more is superfluous.  They seem to be basing their assumptions on research into natural ecosystems rather than cultivated environments and I wonder if this still hold true.  

·         So I add mychorrhizal fungi to the charcoal as well.  But only after crushing the charcoal. 

There is some evidence that adding charcoal to compost heaps achieves the same adsorption of nutrients but I have not tried this. 

How much charcoal to add to the soil is another unanswered question and one that we are trying to assess.  There seems to be two ways of adding it.  

·         Spread it broadcast over the soil.

·         Just add it to planting areas in planting holes or along rows of seed drills.  

At the moment I am just adding charcoal to planting areas. 

A further advantage of adding charcoal seems to be its ability to help the soil to retain water while also allowing better drainage. 

 Charcoal is relatively inert in the soil so there is a great opportunity for sequestration of carbon.  The more charcoal that can be added to the soil the larger and better our crop plants will become. All these different advantages of adding charcoal to the soil seem to be both long lasting and cumulative. 

Found my previous blogs - or some of them.

Sweet Pea

 Just been out pinching out the growing tip buds of the sweet peas. No more damping off thank heavens. After the second leaf I take out the growing tip to encourage two good buds lower down to grow. You get much better flowers from these side shoots than you get if you let the leader grow on.

I am going to grow cordon sweet peas this year. I do not have enough canes to grow them up although they are probably the best things to use. I am going to set up the rows in a similar way to my runner beans with two rows of canes tied at the top with a horizontal cane to keep them in place. This is attached to a post at each end.With the sweet peas I am going to run strings from the horizontal top cane to the ground (plus a bit to bury). I will put some vertical canes every 3′ on both sides of the row. When I plant the sweet peas I will plant the string under them. I have done this several times and the string never pulls out. In fact it is quite difficult to get the string out at the end of the season because the sweet pea roots have grown around it. It looks better if you keep the string fairly taught.I only use nylon string because ordinary string will rot off.

Last year I grew sweetpeas and they were very good indeed. I watered them every week with a weak comfrey liquid. One of the allotment holders near me said that her dad used to grow championship sweet peas using only comfrey liquid and I can believe her.

It is getting cold again tonight so I will not be watering. I like to keep my seedlings just damp so that I do not get any more damping off.