Monday 27 January 2014

Starting to clear and triple dig an allotment (16)

Why dig the allotment?

Digging has long been a method of clearing the ground of weeds and it is good to find that even in the past gardeners have struggled with the same perennial weeds as I have to on the new allotment.  

 Mawe and Abercrombie (1778) suggest "In the course of digging, all root weeds that are perennial should be carefully picked out particularly couch grass (Elymus repens) and bear-bind, the Convolvulus sepius, (what is now called Calystegia sepium) for the least bit of either will grow, increase greatly in summer and prove most troublesome weeds."  "But slight rooting weeds on the surface being turned clean to the bottom, will rot, and never trouble you again."

They also recommend skim digging - taking off weed turfs and putting them at the bottom of trenches.
"In all trenching, whether one, two or more spades deep, always, previous to digging, pare the top of each trench two or three inches deep or more, with all weeds and other litter into the bottom of the open [trench] which not only makes clean digging , and increases the depth of loose soil, but all weeds, as also the seeds of them that may have scattered on the surface are regularly buried at such a depth that the weeds themselves will rot, and their seeds cannot [germinate]."

If the allotment soil was clean of perennial weeds, I would be skim digging.  However, the safest way to remove all perennial weed rhizomes is to sieve trench dig.  

Now I have just read a blog on the myths of gardening and one that says that aeration of soil should not be the primary reason for digging.  

It could be said that adding carbon depletes nitrogen; adding nitrogen depletes carbon; adding air depletes both.  
The biology  is quite clear.  To avoid nutrient depletion the ground  should not be dug unless  large amounts organic material can be added to the soil.  It can be in the form of weeds, manure, compost, shredded brushwood, logs, paper and cardboard.  

I add copious amounts of organic matter to the soil and, if well rotted, mix it by sieving throughout the soil profile.  This will replace the organic matter that increased oxygen allows to be removed through the heightened activity of soil heterotrophs when they take carbon to burn for energy and carbon and nitrogen to build their bodies.  Carbon is removed as the gas carbon dioxide and nitrogen in the form of nitrous oxides or- eventually nitrogen gas.  

Jethro Tull in the 1700s asserted  that soil should be "moved" quite often and that pounded earth was plant food and this may well be based on a misunderstanding of plant nutrition.  However, he based his comments on the observation that when soil was ploughed plants grew well and free of competition. Digging does release nutrients through incorporation of weeds and organic matter throughout the soil profile.  

It has been suggested that organic matter can be incorporated into the soil by mulching the surface of soil and allowing worms and other soil animals to mix it through the top soil.  This mimics the natural way that soil is formed.  Yet there is evidence that the formation of soils naturally takes considerable amounts of time.(Alexandrovskiy 2007) and, while it might be good for the soul, I would rather not wait.

I cannot believe that digging will cause a depletion of bacteria in the soil.  They are too small to be affected greatly.  Digging will cause larger animals and fungi to be disrupted and this must be considered when digging.

So, at the cost of possibly breaking useful fungi hyphae, I will continue triple sieve trench digging to remove weed rhizomes.  However, after this initial clearance of the allotment, I doubt whether I will dig as deep again.

Saturday 25 January 2014

Starting to clear and triple dig an allotment (15)

After going to the RHS Level 3 Diploma course at Birmingham Botanical Garden, I decided to call in to the old allotment and get some more two foot slabs for the new allotment.  The slabs I am taking are retaining one of the beds but I will only be planting green manure here this year and the soil can fall into where the path was, and  levelled off before sowing green manure.  The spring on this part of the allotment is flowing constantly and making the ground particularly waterlogged.

However,  as I got to the allotment there was an enormous clap of thunder and the heavens opened.  I just got to the shed as a very heavy hail storm started to bounce large ice crystals off the allotment. Absolutely no reason for staying any longer and I retreated quickly to the car to go home.  So not a very successful day today.

I doubt that anyone visiting the new allotment would notice the path and would take little notice of whether it was straight or not.  However, it has been annoying me.  Although, reviewing the situation, I think that every allotment should have a wonky path.

I carefully marked out the path and put a line down - which I have been religiously using to position the two foot square concrete slabs.

If you look back up the allotment then they look all over the place.  Also as the new allotment slopes down and the slope is not even the slabs are not very level either.  The slabs do butt up against each other well and I can take a shovel and scrape the mud off the slabs without catching on each crack between the slabs.

I could take them all up again and redo but I think that they add character to the plot and I should leave them the way they are.  (And that is exactly what I am going to do.)

Whatever they look like; they make pushing the full wheel barrow very much easier and that is all that I need of a path.

Anyway, I planted some sage plants next to the curbing.  They are a bit scraggy this time of year but they are disguising the wonkiness of the path quite effectively.  I will put the rest of the herbs alongside the path to do the same job.  I've got two large pots of Mentha piperita "Grapefruit" ; a Mentha piperita "Chocolate" and quite a few self seeded parsley plants (Petroselinum crispum) to go in alongside the curbing.

On the old allotment, I have some Russian tarragon, rainbow sage, thyme and fennel still to move to the new allotment.  The rosemary on the old allotment has died but I have about 20 seedlings in the greenhouse which will join the other herbs alongside the path.  I think that there are some herbs that appreciate a little protection through the winter and I will be putting the rosemary in the greenhouse next winter.

I am still unsure where to plant the pleached bay tree but I would like to plant it with the other herbs.

I have taken up as many of the carpets and plastic sheets at the bottom of the allotment as I could.  There are still several that are covered in shredded brushwood and I will have to clear this off before I can move the carpets.  The shredded brushwood has decomposed and can be added to the top soil as a conditioner.
Moving the carpets and plastic sheeting has exposed a lot of Calystegia sepium rhizomes and I spent some time just pulling these off the ground and putting them on the weed pile to dry off.  I know that drying is not the process that can be associated with this time of year but the rhizomes have been removed from the soil and are exposed to the wind and any sun that we get.  However, the amount of rain we have been having will make this process take a lot longer.

I have removed all the stones that were in the pile of stone on the extra quarter allotment and put them into the greenhouse path trench.    This has filled the trench and I have levelled it in preparation for laying concrete slabs.  I will not put slabs here until I have finished the main allotment path down to where I am presently digging. This has given me more space to dry out the weed rhizomes.  So I am moving the pile, shaking the rhizomes well to knock off any soil that is sticking to them and putting them where the old stone pile was.  This will give me room to dig a couple of trenches out and sieve the soil so that I can plant my rhubarb there.  I have decided to separate the rhubarb putting the named varieties Champagne and Timperley Early in the fruit bed and the rest in a bed of their own.

My grafting tape and bees wax has arrived through the post and have been carefully stored away in my gardening box.  I will be using these in March.  I will have to make sure that my grafting knife is sharp too.

I also bought a couple of minibeast homes to put up on the posts that are around the allotment.
Ladybird and Lacewing box from Wildlife World 

Thursday 16 January 2014

Starting to clear and triple dig an allotment (14)

I have completed the trench 10 across the allotment, dug out the path and put the top soil on the growing area.  It took a while to do this because the carpets and tarpaulins had not covered this area and there were a lot of couch grass and nettle plants that needed to be taken out.

I dug out soil from the greenhouse path  and put it on the new potato bed where the surface of the soil is a little low. I hate leaving very good topsoil under paths so try to dig topsoil out and fill the path trench with subsoil and stones.

This left me with a big hole where the greenhouse path will go.  I used subsoil from  the allotment path to put into the greenhouse path hole.  It did not completely fill the hole so I will be using stones to make it up to surface level.  This left me a hole two spits deep at the end of trench 10.

I had removed a very large, heavy stone from the subsoil of trench 9 and used it with stones sieved from the rest of the trench  to make this part of the trench up to surface level capping it off with subsoil. The concrete two foot square slabs will go over the subsoil to make the path.    I now have another two spit hole in the trench which I  filled with brushwood and shredded willow and covered it with the subsoil.  I will work backwards covering shredded material with subsoil in the same way until I reach the other end of the trench.
There is still a lot of mare's tail in the subsoil and it is particularly difficult to get it out when the subsoil is as wet as it is.
Before putting the topsoil back into the trench I am going to spread a layer of horse manure over the subsoil.
Then it is on to  trench 11.

In order to have enough stone and subsoil for the greenhouse path, I am going to use the stone from the old allotment path.  I made this path last year and there are two spits of stone underneath it.  However, I will need to fill the hole I make extracting these stones with some good top soil.  I am hoping that the mound of soil at the end of the allotment will be sufficient.

So its a bit of a merrygoround at the moment but it is working.  I am getting extra top soil on the growing beds from the paths, the paths are being made of  stones and subsoil topped off with concrete slabs, I am reducing the level of the mound at the bottom of the allotment and digging trenches out to remove all the mare's tail and bindweed rhizomes.

I started this project on the 3rd of September 2013 which means that I have taken four and a half months to dig over about 3/4 of the allotment.  Without the bind weed and mare's tail it probably would have taken me about a week - maybe two.

Wednesday 15 January 2014

Starting to clear and triple dig an allotment (13)

Well, it has taken me some time to dig trench 10 right across the allotment but I have almost done it now.  The weather has been slightly drier and today was quite warm as well. Digging does not take that long once you have the dry ground to work with.  I will continue to sieve mix in the rock dust because I have quite a bit.  I will probably have enough to do all of this half of the allotment and some over to put on the potato bed.

I have cleared away all the carpets and rubbish at this end of the allotment which gives me a fairly good run through to the large mound of soil that was probably a compost heap in the past.

I am going to use this soil to mix in with top soil that I am taking out of the trenches now.  I am hoping that the compost soil is going to have a lot of organic matter in it because there is not much organic matter in the top soil that I am digging now.

I am still taking out bindweed and mare's tail throughout the soil profile.  Although I cannot sieve the subsoil, I will have to fork it over very carefully to make sure that I take out all the rhizomes.

I will take the camera tomorrow and get some pictures of the new allotment to show the development and how it has changed over the winter.

I have bought the old vine, Vitis vinifera, from the old allotment and planted it on the new.  As planned, I trained it to the guyot system and am very pleased by the way it has settled itself in.  I planted it with a dose of mychorrhizal fungi to help it to establish quickly.   I have just wound the vine stems around the wire supports in order to keep them from being damaged but I will go back and tie them in with wire ties.  A very successful project.

Sunday 12 January 2014

Starting to clear and triple dig an allotment (12)

The large amount of rain we have been having over the past couple of weeks has meant that even I have had to stop digging.  It takes a trench half full of water to stop me but stop it had to be.

I have finished putting curbing slabs alongside the top of the allotment.  They are not very straight and if they annoy me, I will take them all out and do them again.  However, the plants will grow up and cover them and I will forget how crooked they are.

Moved more of the bay plants next to the path - carefully.  The other bay plants are showing signs of die back after I had moved them.  I don't think that they have suffered too much and will grow away in the spring.  Between the bay plants I have put the Pyracantha rogersiana.  They are tiny seedlings at the moment so will not interfere with the bay (Laurus nobilis.)  

I finished planting the strawberries Fragaria ananassa  in their bed.  I will get some straw for them in the spring.  I squashed in all the plants from the old allotment.  I have hundreds of strawberry plants still on the old allotment so I will be able to replace any that do not survive the winter.

I have transplanted the Salix alba vitellina next to the new compost heap.  It is in a good place because it will hide the compost bin a little, protect the allotment from north westerly winds and provide me with a lot of canes and polls.  I am pollarding it at the moment to encourage it to send up lots of useful stems.

I have planted two of the Salvia officinalis and Petroselinum crispum by the new path.  The herbs will be planted alongside the path so that when they are brushed past I will get their scent.  I wasn't going to plant the parsley next to the sage but I needed the big plant pot it was in.  I used the plant pot to pot up the M9 apple rootstock in readiness for grafting in the early spring.

I have laid twelve two foot concrete slabs alongside the allotment to make a path down the side.  I only need another thirty to finish the path.  As I have been going down, I have been planting mint rhizomes under the slabs so that they will grow through the cracks.  I do this for four reasons.

  • I get the scent of mint when they are crushed while walking past.
  • The mint will compete with any weeds that try to grow between the concrete slabs. 
  • It restricts the mint to the path and stops it spreading into the growing areas.
  • And finally it gives me another mint plant to pick for cooking.  

I have planted Mentha sachalinensis, Mentha spicata, and Mentha suaveolens and still have Mentha x piperita f. citrata "Chocolate" and Mentha xpiperita f. citrata "Grapefruit" to plants.  If I put Mentha aquatica into the pond I will have six different species of mint on the allotment.

After putting curbing slabs alongside the path to keep the soil from falling over, I moved the old carpets onto the dug part of the allotment. Some of this area is covered by the green manure but now a substantial portion is bare earth.  The soil was getting battered by the rain so I thought that I would cover the bare earth with the carpets and tarpaulins.  This has removed the carpets from the area I wanted to dig next, and given me access to the large old compost heap at the end of the allotment.

The compost from the compost heap will be sieved into the top soil as I dig back towards the Crataegus monogyna hedge.  This will take out the compost and flatten the ground so I can dig and use it for planting. The compost area will be the roots and leaves bed for this year.  I will try to sieve the soil quite deeply here because I want some long roots.
Went home for a well earned cup of tea.