The Accidental Smallholder Forum
Growing => Vegetables => Topic started by: Fleecewife on August 13, 2016, 12:29:53 am
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My polytunnel has been under constant cultivation for the best part of 20 years. In the early days it produced bumper crops and was so prolific it was like a jungle inside. For the past few years it's gradually been getting less productive, in spite of using the same methods and plenty of compost and manure, and rotating as much as one can in such a small space - 7m x 14m. The plants just don't look totally healthy. We have had spider mites for the past 3 years. This year, after having to dispose of the cucumber plants, we have managed to keep the mites at bay by daily soapy spray. Even so, the sweetcorn is a disaster, yellowed and not well pollinated, and the tomato plants and squashes are decidedly scrawny. We do have gigantic self-sown brassicas though, so it's not all gloom.
Is this soil sickness? If so, is the only action to move the tunnel to a new location? What actually causes the sickness? Is it a build-up of low grade pests and diseases in the soil, or could it be having the soil not rained on for so many years? When we changed the cover a few years back we left it off for a month to give the rain a chance to soak the soil - there wasn't a single drop of rain in the whole of that month ::)
If anyone has experience of this phenomenon your experiences and any advice will be gladly received :garden:
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Have you tried double digging the soil? Alternatively, remove a good layer of soil - at least a spade's depth and replacing it with soil from elsewhere.
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I'd have thought that significant soil parasites would be noticed. At a guess I'd suggest a trace element imbalance but without analysis it'd be impossible to figure and could just as easily be too much than too little. Fr'instance constant watering with a very hard water could either increase levels of some element or paradoxically there may be something in the water that binds an element.
I had issues last year early on with my glasshouse... hindsight and I'd probably chucked in too much wood-ash. Replacing a layer and watering with miraclegrow solved that for me and this year it's back to normal.
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When we bought our last house the soil was very badly depleted having been used for 30 years and nothing put back. We got very poor crops and the root vegetables used to split in the soil. Turns out it was a trace element deficiency (Boron) so we sprinkled VitaxQ over the whole area and the result was nothing short of miraculous.
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Where are you getting your manure from? Is it from a farm that is using high amounts of chemicals? Is the compost made by you? Have you tried the no dig method of laying cardboard muck and greenwaste and leaving over winter? Are you using chemicals in the tunnel? I assume not.
I am just starting out but I dont think there is anything called soil sickness there is of course soil that is dead and lacking worms and micro life. Even so laying manure (cow) and compost should bring the condition up leaving it so 6 months you should have an abundance of worms. If you incorporate enough manure or compost then you shouldnt need to add expensive elements or mess with it all all.
I would def build up the soils and leave it over winter. Refer to Charles Dowding for mulch methods.
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Hi everyone and thank you for your comments :wave: There are some really helpful ideas and suggestions there which have got me thinking :garden:
I've been doing a bit of research and it seems that soil sickness is a problem with large scale monocultures, chemical use etc.
So it's not that. But there's definitely something wrong.
Farmers wife, I have used organic, no chemical methods all my life, feeding the soil to feed the plants. We make our own compost from garden waste, and FYM using our own hen house cleanings and sheep droppings. The straw we use as bedding will almost certainly have had chemicals applied during growth, but I had hoped they would have degraded by the time we spread them. I need to look into that more closely, but thinking, everything grows fine outside (except peas and beans this year :idea:), using that FYM. I don't know of any chemical free growers of cereals here. There have been a lot of seeded weeds recently so we burn those rather than compost them. Having in the past found extensive damage due to chemical contamination in broad beans at my brother's farm (the spray tank hadn't been properly cleaned after using weedkiller, before spraying something else - the horrors of chemicals :o) The plants became curled and deformed, and failed to grow properly or crop well, and that's not what I'm seeing here. A few years ago though I did see something similar in tomato plants in the tunnel, which was eventually traced back to the compost I was using which must have had traces of Aminopyralids. I've changed my compost, and I haven't seen that kind of damage again.
I use the 'cover it for a year' method in the outside beds. This year it's in earnest as I can no longer dig at all, so half the garden is covered with a giant tarpaulin bought specially (manure will be spread later) for next year's crops, and the half we are currently using will be covered this winter and next year. This has worked beautifully for us in the past, giving perfectly crumbly, fertile soil in the spring, which can be planted up with no further working at all.
I haven't used this method in the tunnel though, other than covering bare areas to keep weeds down. Our normal routine is to dig the whole area (Mr F does that bit), just single digging MGM as we don't have enough depth of soil to double dig - it just brings up subsoil and broken rock. Then we mantis in FYM or compost, depending on the intended crop, so it's well chopped and goes down as deep as there's soil. We then dig big planting holes or rows and fill them with water a couple of times before the plants go in, as the soil is very dry after the winter.
It sounds perfect, but clearly it isn't.
The fact that the self seeded brassicas are doing splendidly implies the soil has become alkaline. I wouldn't expect this as we do add a lot of FYM, which tends to make soil acid, but we also spread wood ash which is alkaline - maybe too much pgkevet. I think the first thing I'll do is a pH check. If that's wildly out then it could affect trace element uptake so that's what I'll check for next Chris.
I think being realistic there's no chance of removing the top foot of soil and replacing it. If that is necessary then it would be easier to move the tunnel onto fresh ground and start from scratch.
To anyone who's read this entire screed, than you and thank you for your replies - there's enough to keep me busy for a while there :thumbsup:
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I would stop digging as that destroys the fungal hyphae in the soil which form symbiotic relationships with plants and help to transport nutrients to them. I would also think about remineralising the soil. You could use Rockdust for this or for a more targeted approach I would recommend reading "The Intelligent Gardener" by Solomon which is all about getting the mineral balance in the soil right.
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The book sounds really interesting CDC - I'll see if I can find it.
We're kind of stuck with having to dig as we have been invaded with creeping thistle. The roots go down as far as there's soil, and spread horizontally deep down. The thistles are undeterred by mulches organic or barrier. If we try just to pull them out then they proliferate madly. I agree that digging, ploughing etc destroys the structure of the soil - it also upsets the worms and soil micro-organisms, but until we can get on top of the thistles I don't see what else we can do.
'How to' books on gardening skip over the problem of perennial weeds by their little catch-all phrase - 'first remove all perennial weeds' :roflanim:
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Pull the thistles now. When they are flowering all of their efforts have gone into that and if you put on some thick gloves and grab them at the base some of the root will come up. It is usually enough to stop them regrowing or to significantly weaken them.
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My friend Don ran the same polytunnel ( with new covers ) for well over 12 years ( till he died of old age ) with great success. he never had any crop reductions far from it ...the longer he ran them the better his crops .
Question ?
If you soak an area with water for 1/2 hr or so & put a couple of square yards of cardboard , , black plastic sheet , sacking or some other barrier over it after a few days will you have worms at the surface or close to it underneath where it has been well wetted ?
My old Percy Throwers , " Encyclopaedia of Gardening " published in 1962 says that red spider mite is common in glasshouses ( polytunnels wern't invented till much later on ) is worsened by by a hot dry atmosphere & as a consequence it is very very effective to spray clean tap water in the glashouse to kill them off.
At the men's sheds group I go to I set up a Hozelock battery timer with Antelco sprays heads using 15 mm main supply lines and 1/4 " take off lines. I've set it to do programme two which gives five min of fine spray once every 12 hours (07.00 A.M & 19.00 P.M )sessions of 5 min each.
This has cured the red mite problem entirely .
Initially it also started to show red rust on the 10 wek leeks as I'd set the timer to operate in two 15 min slots in 24 hours .
Percy also recommends using a sulphur candle to fumigate an empty greenhouse , as it not only knocks mites on the head it also does in lots of other bugs in the empty glasshouse
I feel that if you are perpetually growing inyour tunnel this may be part of the problem of pests moving from one crop to another without being interrupted for a while .
Something else comes to mind if you get a hot day outsidesay in the 80 oF's inside the tunnel it can reach well in excess of 100 oF . This is far too hot for most plants in the UK will really knock the growth and leaving them susceptible to pest & disease attacks .
Now add in a not quite enough water situation when the plants need it (not when you feel like watering them ) & you have a recipe for disaster.
DG Hessayan's , " Greenhouse Expert " is a book I'm happy to recommend for it's how I started our glasshouse ( concrete floor ) seven or so years ago . The only problem I've realised I had was the start of a greyish white powdery mildew , cured by putting a car boot sale electric oscillating fan under the seed bench on a timer set up & switching it on so as to get better air circulation .
This extra air circulation is also good on hot days when the auto air vents open up & it is still too hot without the fan .
It cured it and also gives the unintended consequence that the gentle air movement causes plants to sway ever so slightly and thus they grow stronger stems .
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Clydedaleclopper - you've clearly been pondering my problem - thank you.
I bought the mineralising book but I couldn't get past the self-justification bit - sorry.
For the tunnel being too hot, well, this is Scotland and we certainly haven't had any temps anywhere near 80. Nonetheless, it does get really hot in the greenhouse, although the tunnel is usually ok as it's well ventilated with doors and big louvres at both ends, and lies east-west to catch the prevailing breeze (and it sure is breezy here). I do wish I could use a fan, but we have neither electricity nor mains water to the tunnel, in fact we don't have mains water, full stop. When it gets hot in the greenhouse then I have to fan it by hand, and damp the whole place down. If it's really hot then I would take the pots out, as everything in there is in containers. For the tunnel, we water a lot, most mornings unless the soil is still damp from the previous day, and we give it a thorough soaking, not just a surface splash. Plants such as beans, tomatoes, peppers and chillies are sprayed with water twice a day to help flower set and prevent blossom drop. I think what could help waterwise would be to spray water over the metal bits of the tunnel - hoops and reinforcing bars, in case there are mites hiding.
I do agree that we should try clearing the whole tunnel for the winter so there's no plant material for diseases to survive the winter on. It would be difficult as all our winter crops have to be grown inside due to the harsh weather. The soap spray does work against the mites, just not total wipeout as you would get with chemicals.
Earthworms - it depends just which part of the tunnel, and when. Our garden outside and all the pastures are heaving with earthworms - Darwin would be proud of us. As a method of weed control, we let the soil dry out completely in the tunnel at times, especially in the winter. I can see that this has its drawbacks.
Incidentally, the tomatoes have recovered from their scrawniness and are producing well. As this is a cherry - Sakura - they will go on producing for 2 or 3 months more, so we should get a heavy crop from them :fc:
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We don't have mains electric to the poly either but we do have a 12 volt fan that runs off a solar panel. It makes a real difference to the air flow and tends to come on when it's most needed I.e. when the sun comes out and the temp in the poly really starts to climb. The poly is 50 ft long so air movement in the middle isn't great even with both sets of doors open and I've found this to solve the problem of that still and damp bit half way down.
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Brilliant idea Piggerswiggers :thumbsup: Why on Earth didn't I think of a solar panel :dunce: ? What size do you need to run your 12 volt fan?
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Hi FW, we've completely over specced it with a 100 watt panel as that was what we had spare at the time. However I've just looked at the back of the fan and it says rated as 15W. At the risk of stating the bl*****g obvious the panel needs to produce at least 15 Watts.
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:idea: ;D
I handed the idea over to Mr F who loves stuff like that and agrees it's a great idea, so he has it all planned and ready to order for next summer :garden:
We also have a plan of how to rejuvenate the soil in the tunnel over the winter, so :fc: we have a better year in 2017 :sunshine:
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FW,
Can you get hold of cow muck & real straw beddings that they have over wintered on ?
There will be all manner of nutrients and part decomposed matter in it .. it's far better than horse muck for a cows digestion kills almost all weed seeds ..a horses does not .
Even neat plenty cow pats laid on th soil and broken up once they have dried out is a good soil rejuvenator .
Imagine me as a 22 year old hunky straw haired blue eyed golden skinned Adonis , recently back from being 7 months with the UN in a rather warm country .
I'd begged next door for their old pram they wanted to gt rid of , to go three miles to collect cow pats out a field of cows . On bringing them home ( five loads in a week ) drying them on wriggly tin sheets and rubbing them to bits when dry , I spread the resulting powder about 1/8 inch deep over 40 square yards of newly dep dug destoned de weded very chalky soil 6that hadn't been dug for many a year.
Then digging it in well before watering on in and sowing my first seeds the next day . The only problem was I didn't know that the high nitrogen levels released in the ammonia would make carrots & other root crops look like cows udders with about the same number of roots as teats .
That ammonia ....... it's released in decent quantities from cow & chicken muck when it's fresh or wetted . It is a natural pest fumigant , till it turns into nitrogen it is also a source of food for some beneficial fungi & moulds .
So this idea may be of some use to you wrt red mites as well especially if you can close up the treated well manured & wetted tunnel for a few days .
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The Adonis bit sounded good until you mentioned dabbling in the cowpats :roflanim:
The only cowpats I have access to are all from animals treated with persistent wormers. We tried them when we first came here (not knowing about the wormers) and it was several years before there was a single worm in the pile and it started to rot properly.
What I do have is henhouse cleanings - straw bedding - and sheep shelter stuff - also straw - well mixed with droppings and urine. We restraw the shelters frequently through the winter and especially at lambing, so it's well mixed and well soaked. The hen stuff gets composted for about a year usually although this past winter we made the mistake of covering the heap too soon so it wasn't wet enough to rot. It's now had rainwater, pond water and Mr F's special evening stroll additive so is well wetted and will be ready in spring. In addition over the winter we spread the hen house stuff directly onto the soil, then when it's wet enough we cover it. By spring it's all gone, leaving lovely useable soil. I've never used horse dung although it looks so lovely ??? - gardeners are strange 8)
I'll try the henhouse stuff for ammonia in the tunnel as you suggest - maybe Mr F will add a little something to it.....
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I had a henhouse with a mesh floor. I dug out the well decomposed stuff underneath it after a couple of years and used it to fill a slightly raised bed and planted purple soprouting broccoli that a friend had spare. After a couple of weeks mine was twice the size of hers. You could practically see it grow. (sadly a passing red deer hind spotted it just before I could pick it and cleared the lot).
Goat manure also works wonders. When I had some deep raised beds built so I could continue to grow stuff after becoming disabled, they were filled with rotted goat manure and I planted straight in it. The crops did well. At the end of each year, the beds are topped up from the manure bins and always grow well. I have squashes going berserk in there this year together with leeks and a couple of massive pumpkins. The beetroot in the other bed are a good size as well.
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Fleecewife - did you come to a solution with your soil issues in the polytunnel?
We are having similar problems, and I am trying to work out how to solve it without major (financial/time/physical investments... we have goat muck galore, and I was planning on also taking out a good portion of the existing soil, then using Rockdust and seaweed as well. Just not sure if I would be better to also get some topsoil brought in? Or would bog standard multi purpose compost (just for the top layer anyway) be more useful?
(As we are also expanding with a 3x10 Keder to be delivered in February, I will need to build up beds in there as well, but it won't be fully on-stream until next spring anyway).
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Hi Anke
We have the hens in the tunnel for the duration, and even if the restrictions are lifted we will leave them in there over the winter. I have high hopes that they will sort most of my problems of pests and fertility.
Your goat manure sounds ideal - we use strawy sheep muck, worked in with a Mantis, very well rotted, and keep hen house cleanings for outdoor crops like potatoes.
I use seaweed meal on all the veg beds every year, indoors and out, and I think it really helps. Last year we found a huge family of voles living in the sack - lovely bedding ::)
We also have endless molehills and apart from the fact that the soil has to be sieved, it's very fertile for freshening up and if we can afford the time and strength then that's what we'll do this spring. To buy in top soil sounds good as long as you know exactly where it's coming from, and what weed seeds it's going to bring with it. When we had our front garden done the people doing it removed all my lovely volcanic topsoil and brought in some horrible clay stuff, full of weeds and stones. I've spent several years trying to sort that.
I'll be really interested in how you get on with improving your soil. If I remember, it's very dusty-looking, so maybe an extra dose of humus would be worth adding. I'll also be interested in how you find your keder house. I've seen them advertised of course......
The other thing is to encourage earthworms. All the added humus and manure will help, but the soil also needs to be kept moist or they will stay outside.
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Thanks for getting back. Hens in the polytunnel doesn't sound bad, but alas ours is mainly hay storage at this time of year and not fox-proof, so the chooks are just in their runs (with some improvised covers on of course).
But doooh... I hadn't thought of mole hills, plenty of those and local too... probably to be combined with some multi purpose compost. It is just that I need a soil surface to sow into, and the muck alone is not fine enough.
My Mantis went east... to my parents as they have very sandy soil and we had found that we just didn't get enough of a window to use it in spring, except in the polytunnel. My parents love it!
I am really looking forward to my Keder, massive investment though, they are not cheap... it will take us most of the summer I think to set it all up..., it will have a watering system too...
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We've found a way which works really well to make a fine tilth for sowing into directly, as long as you have earthworms. It takes a while though and it's probably too late this year. We just spread the well rotted FYM or compost, plus seaweed meal, wood ash, molehill soil and anything else which is going in, over the surface of well watered soil. We then cover it closely with a tarpaulin held down with bricks or old stobs, and leave it for as long as we have, certainly right through the winter. Once you reach sowing time, you peel back the tarp and the soil surface is weed free, fine and WARM, and ready to sow. It's magic :garden:
Maybe that would work well for your keder house, especially if you do it even before the house is up.
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Just came across this thread and hoping your soil condition improves FW and wondered if you have done a simple soil analysis on a few areas in the tunnel? If you have an agricultural college nearby you might get some very interested students who would come an do an indepth analysis to tell you exactly which minerals you are lacking.
We grow nearly all of our veg in a massive polycarbonate tunnel (this is after our two solar tunnels blew away :o) and we up until now we've used our well rotted cow manure which as someone else said is probably the best thing you can put on soil. This year we shall be using goat and chicken manure but we make a point to leave chicken manure to rot down as it is too strong to use fresh.
Apologies if you already know this :eyelashes:
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You're right Polyanya, I should get a proper in depth soil analysis done. The fact that we have splendid brassicas in there hints we have a slight pH imbalance, and no problem of general fertility. There is an organic lab somewhere down south which does soil tests, but for a price. I'll look into it. I think the more agricultural labs give advice which can be difficult to translate for an organic system. if my son was still at Uni he could have done it as he studied agriculture, but that was a long time ago.
The other problem we've had for the last few years is red spider mite - like the poultry variety but sucks sap instead of blood, and they wrap all the plants up in copious amounts of webbing. We are slowly getting on top of them, but with the poultry in the tunnel for the duration of the avian influenza restrictions, it's going to be difficult to do our usual anti-mite measures this year. The hens kick up a heck of a stour though with their dust bathing, so I'm rather hoping that will suffocate the mites - it certainly gets to me :D
I usually have a lot of veg packed into the tunnel so it's a bit of a jungle. This means the mites spread from plant to plant, and the air circulation might not be as good as it could be. I shall be growing less this year, so each plant has more space. But I will get the soil tested :garden:
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Fleecewife I am by no means an expert but I have been growing veg for a few decades and like yourself we run our croft on organic principles which I genuinely believe requires a somewhat 'intuitive' approach to gardening. The splendid brassicas to me might suggest a soil too rich in nitrogen, which might point to the fresh chicken poo? So if the soil and all the tiny micro-organisms that make up the soil are imbalanced, the pests move in. This may be a bit over simplistic but possibly worth looking at?
Wrong time of year I know but foliage is a good indicator if anything is amiss - you know yellowing veins or edges all means plants suffering from something or other. The RHS has a really good section about recognising soil deficiencies from the colour of leaves in one of their vegetable growing books, might be worth a trip to the library :thumbsup:
I really feel for you with the spider mite problem - we have very few issues with pests in Shetland (too blummin cold!) but had an infestation of earwigs in the solar tunnel a few years ago - it got very bad with courgette plants in particular being decimated, until we noticed a blackbird visiting via a ventilation vent we'd left open all winter, problem solved, no more earwigs :thumbsup:
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The hens have only been in the tunnel since early December when the restrictions were put in place, so fresh chicken droppings are a new thing. It's quite a large tunnel and only 8 birds, and we will turn it in well, but I'll watch out for burning of foliage etc in the summer.
Normally we use well rotted sheep manure plus straw bedding from outdoor sheep shelters in the tunnel. It's composted for a year, then worked in with a mantis, but it has been suggested above that that is disturbing the soil structure. It does cause a slight pan, but we are used to that so break it up regularly, and anyway our soil is well drained.
Outside we use well rotted chicken house cleanings, again with straw, or we lay it fairly fresh on the ground, cover with a tarpaulin and leave for a year, by which time it's been broken up and taken down into the earth by worms. Everything is ok outside, except that like you only the hardiest stuff grows outside here - too windy and cold. That's why I was stuffing the tunnel with plants, but now I will grow less and allow more space and air for each plant.
I looked up soil testing kits and lab services and the useful ones which do trace elements are expensive. pH and N,P,K testing kits don't get good write-ups for being inaccurate. I'll investigate RHS a bit more - can't remember if they do trace elements too. I have to decide if the cost of a good lab service is worth it, or if I should just continue trying out possibilities and see how well each one works.
Mr F has decided that today we will spread a thick layer of molehill soil over the whole tunnel and let the hens work it in, and pick out any weed seeds. Hopefully that will reintroduce enough soil which hasn't been exhausted by growing in such a restricted space for 21 years. It will also introduce stones, which I'll spend the next few years picking out....
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I've been working through the soil chemistry section in Geoff Hamilton's Organic Gardening book. He goes into detail about all the trace elements, including the less frequently mentioned ones. I don't recognise any of the symptoms mentioned from recent years in the tunnel. His treatment for nearly all the imbalances is to treat with seaweed meal. We add seaweed meal every year, so I'm happy that I don't need to pay for one of the exorbitant in depth lab checks, but I shall do the simpler pH, N,P,K checks. I haven't done pH for several years, and I've never done N,P,K.
So it looks like we will put our hopes in those tests and in the addition of many barrowloads of molehill soil :fc:
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Anglian soul to a greenhouse soil test for under £12, includes the pH, N, P and one or two others if you are not convinced by the accuracy of a test kit might be worth posting them a sample?
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Gosh it does seem like you are doing everything right doesn't it ???, but the mole hill soil sounds like a good idea and the other thing we've done from time to time is to buy a few bags of potting compost (not seed) and adding a couple of handfuls around each plant. Sorry I can't be more helpful :( Shame Geoff isn't around anymore, he was the best!
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Anglian soul to a greenhouse soil test for under £12, includes the pH, N, P and one or two others if you are not convinced by the accuracy of a test kit might be worth posting them a sample?
I looked them up but their latest price list is 2014 - are you sure they're still on the go? In addition to pH, N,P,K they also do magnesium and EC - anyone know what that is? If they are still working, then they do sound the cheapest - same as buying a kit and kits sound less accurate. Thanks for the info.