Scottish Rock Garden Club Forum
Specific Families and Genera => Pleione and Orchidaceae => Topic started by: Stephen Vella on April 28, 2011, 07:21:51 AM
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Theres been much debate on the topic and it seems that the hybrids can and do prefer inorganic fertilisers and arnt fussy about what you throw at them.
Im wanting to know what the growers here have to say in regards to fertlising their species and hybrids?
In pots and out in the garden..is it any differant?
Organic or inorganic, whats the NPK?
Was told to avoid urea..is that true?
cheers
Stephen
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Inorganic every time. That's why you should use a compost that is 80% inorganic plus 20% bark and loam, which is nutrient poor. Inorganic can be controlled and washed through.
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The first principle is to find out what your plant needs. You do that by studying where it comes from and what is known about its natural environment, acid or alkaline, wet or not etc..
Regarding organic or inorganic fertilisers, I don't think it matters. I use a variety such as tomato food, Maxicrop, Miracle Grow, seaweed extract and others. To know how much to use, I employ my most important gadget, a conductivity meter, which measures the content of dissolved salts to determine the strength of the fertiliser solution. My meter measures in units of microsiemens (µS) and I aim at 600 µS with practically every watering.
It also helps to understand that there is a difference whether you use rain water or tap water. If you use rain water, the initial conductivity (content of dissolved salts) is low, in my case about 15 µS and one you can add more food to reach the magical 600 µS. Tap water, however, has a lot more salts to start with, in my case about 500µS, as I live in a very chalky water area, which gives less scope for adding fertiliser before the 600µS is reached. So there is no point filling up your watering can with 5 gallons of water and adding what it says on the fertiliser bottle, because you may under- or (more seriously) over-feed your orchids, which can lead to root burn.
Urea as a source of nitrogen should be avoided as the nitrogen derived from urea does not show up when measuring the strength of the solution and can lead to overfeeding.
I agree with Anthony that an inorganic substrate is more likely to allow cypripediums to survive the average British winter (cold and wet). It also avoids accumulation of salts which could seriously damage your plants. I go even further and avoid the organic content altogether, using a mixture of equal parts of Seramis and well washed pumice. This means that I don't need to re-pot for years, as there is nothing in the pot that can go off (bark) or change the alcalinity/acidity of the growing environment.
The bottom line: find out what your plant needs and give it what it wants. ;D ;D ;D
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I have used Tomorite for the past four years, feeding at 1/4 normal dilution every 2 weeks. My commercial mix is based on one used by Peter Corkhill. Equal portions of perlite, pumice and 2-4 m grit plus up to 15% Melcourt bark products. Peter prefers Cornish Grit but the only supplier I can find wants £300 a tonne I will continue with what I can find as long as it is inert. As my overhead watering system sprays the plants for a minute every hour during this hot weather I do not have a problem with a build up of unused fertilizer.
I found that Seramis did not work for me and I lost numerous plants in the summer when I used it as the alternative to pumice.
Rather than have to give individual instructions to each customer as to preparing their soil I now recommend growing plants in 5 to 10 lt pots using the mixture I described and plunging the pot into the garden in a suitable position. I have seen excellent plants that were planted some years ago in this way and they are thriving. All the owner does it feed the plants well and covers the dormant plant with additional grit each autumn.
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Anthony you make it sound simple...thanks for the advice.
Maren a conductivity meter is something I will have to get, takes the quess work out of it. I use Dam water and tank water. Im wondering if Cyps would prefer all that chalky water?? and I will stick to the inorganics.
Jeff interesting to hear that seramis did not work for you...I use seramis/ perlite/(coco fibre/bark 10%)and it seems to keep the mix moist/free drained. Do you know why it killed some of your plants?
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I spoke to someone at the international conference at Nottingham ( forgot their name ) and they talked about pumice, is this product as hard to get as seramis.
Angie :)
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That would be me Angie,
I obtained my pumice from a firm in North Yorkshire called Viresco. I stocked up last year as they announced that they wouldn't be stocking it in future and were selling off their remaining stocks. I've since heard a rumour (unconfirmed as yet!) that they were so impressed by the number of people who wanted pumice that they may begin stocking it again.
Otherwise it's a bit hard to come by in the UK. There was an extensive thread on the 'composts' section of the forum last year (here's the link: http://www.srgc.org.uk/smf/index.php?topic=1569.0) which may have listed other sources.
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Hi Peter
Just shows how bad my brain is I didn't think it was a forum member but yes it was you, its all coming back now ::) ;D. Thanks for the link. I thought it was great conference, my first but certainly not my last. I was exhausted by the time l got home, so much to take in and all that food didn't help. l was ready for a sleep after every lunch.
Will try that company, hope l manage to get some. Thanks.
Angie :)
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Hi Angie,
If you find someone that sells it please informs us here. I too would like to get some.
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Will do. Have emailed some companies. See what happens.
Angie :)
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Can anyone give me the size of pumice that I would require. The company called me back today ( Viresco ) and said they had different sizes so before I place a order I thought it would be helpful to find out what I need. Thanks
Angie :)
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Hi Angie,
I'd go for 4mm max, that'll come as between 2mm and 4mm.
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Angie,
That's good news that Viresco are selling pumice again - I think that, of the range of grades that they have, I used 3-5mm size - roughly the size of dried peas or chickpeas. The smaller size is good for seedlings (if you're feeling bold and fancy a challenge). I also obtained a bag from them of a larger size (5-8mm?) which is too big really. I tried breaking it up with a hammer; doesn't work, you end up with lots of dust! :-\
You can 'recycle' the pumice: I'm currently using about 75% pumice to 25% leafmould. At repotting time I find that the leafmould has packed down and is too dense, especially if earthworms have got into the pot. I therefore repot in fresh mixture and the old mixture is put in a black plastic pot or spread on a tray and left in the greenhouse for a week or so to dry. It can then be sieved to get rid most of the organic component (this is where the 3-5mm size is useful - it stays in the sieve). The 'old' pumice can then be combined with fresh leafmould and re-used. If you have a large collection of Cyps and plants requiring a similar regime ;) , then you don't need two year's worth of pumice, as after a week or so, you are using pumice that his dried from your first repots of the season.
My (unsubstantiated) theory is that any mycorrhizal fungi associated with the plants can be passed on through the pumice as it is re-used, giving them a head start in the new mixture.
Oh yes, with a mixture this free draining, you need to water regularly, mine are watered automatically with a sprinkler for 15minutes twice a day, which works for me with plastic pots standing on a sand plunge. They are also fertilised regularly with weak tomato fertiliser, the regular watering flushes any excess away, as Jeff Hutchins said in his post.
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Peter thanks for all this information. He never said what they had but said they had a few grades of pumice. I will speak to him tomorrow and hopefully will be able to get some.
I only had a couple of Cypripediums but I got some from Anthony D last year, lovely healthy plants, now I think I am hooked.
I had some a couple of years ago before I came to the forum but I kept them to dry through the winter and lost them. I thought they were a bit tender. Should have read up on them before I bought them, expensive mistake ::) I am never sure how much water to give my plants in winter but speaking to Anthony and seeing where he kept his plants was a big help.
Isn't this forum great, where else would you get help and advice like this and its free 8) ;D
Maren thanks :D
Angie :)
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Peter spoke to a really nice gentleman today from Viresco and he is sending me some samples and I was glad to hear that he had 2-3mm in stock and will send to Aberdeen. Thanks for the help.
Angie :)
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Angie,
2-3mm is a bit small if if want to re-use it year after year as I suggested, it's ok if you are not planning to repot regularly. If you can get the next size up I find that better.
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Hi Angie,
definitely one size up as Peter suggests. It'll get smaller with wear and tear - or is it erosion?? ;)
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Ok, I think this was all he had in stock. ( 1mm and 2-3mm ) But will check before ordering. It would be better if I could use it again, makes the price not feel so bad then.
Thanks again.
Angie :)
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I used to buy pumice direct from the importer and sell on but found that there was no call for it them!!
You could try e-mailing them and asking costs or if they know any outlets of their products. I was buying at 500kg a time of grade TG (5 or 6mm) £0.52/kg delivered. It's the delivery cost that makes it expensive when ordering any less. Try searching online for pumice aggregates and you may find more. It's used extensively in the building trade and very cheap until it gets repackaged and sold for horticulture!
Offices are based in Newcastle Under Lyme but storage depot I think is near Hull.
http://www.pumex.co.uk/website.html
you can also e-mail the following companies:-
http://www.yoraggltd.com/
http://www.techfil.co.uk/Markets/Horticultural-Gravel
Or an expensive option would be - http://www.specialistaggregates.com/pumice-gravel-p-1540.html
Regards
David
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Thanks David for this information. I never new it was used in the building trade. My husband is in construction and has never came across it.
Like you said its the delivery costs that makes everything so expensive.
Angie :)
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I went to the local garden centre (Kings Plant Barn, Botany) to get some course sand for the lawn. I notice it is pumice sand. I also noticed they sold bags of pumice gravel in at least three different grades, primarily for hydroponic cultivation.
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Hi,
last time I contacted Maple Aggregates (info@mapleaggregates.com), they quoted £200 for a cubic metre bag of 3-5mm pumice. That is a very good price. They even sent me samples, which I still have, but that was a few years ago.
I went to Belgium with a van and bought a cubic metre of loose pumice, which cost me roughly the same, including the cost of fetching.
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This pumice is hard to get, the company sent samples but yes I think the 2-3mm is to small the next size is 5- 10cm. The man was really helpful.
I have emailed some more of the links that David has given. David I think you need to import pumice and sell it to us or Maren you need to drive to Belgium again. I will come and help ;D
Angie :)
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Hi Angie,
I'm quite prepared to buy a tonne bag of pumice, if I can be sure that people want it. As David says, often these things seem like such a good idea and then they go flop. The hurdle that remains is the cost of getting the pumice to the people who want it. It's the shipping that kills this sort of community project. :'(
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Maren
If you use a courier company like Parcels2go online it cost under £10 for up to 25kilo and it will be the major courier companies like DHL that collect from your house and deliver in 1-2days.
Angie you could ask the depot in HUll for a test bag of 25kg which is about 50 litres when dry and arrange your own courier as above to collect. May be worth asking saying you would like to test the product before buying in bulk.
One word of warning for anyone else buying direct from the importer on a pallet in 25kg bags - ask for bags of dry pumice as a 25kilo bag that is wet will end up being 15kg when dried out in the garage.
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David,
that's all very useful advice. I appreciate your comment about the wet or dry weight, but I rather doubt that the supplier will make that distinction. My guess is it'll be wet and turn out a lot less than hoped for. But there speaks the voice of the long suffering purchaser of things that don't turn out to be as expected. :'( :'( :'(
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There could be a case for one person to place an order then bring supplies along to a show or conference for other people to collect there. We're probably now talking about repotting in the autumn so the SRGC discussion weekend springs to mind (unfortunately we've missed the chance to organise something for the international conference).
Having previously bought 25kg bags from Viresco before, I have a feel for what 500kg would equate to (in terms of volume - it's 20 x 25kg bags, obviously). If there is enough interest, than I could conceivably fit say 10 bags in the car on the way to Dumfries. It would, I suppose depend upon the cost of the pumice (using David's figures, the cost of carriage would be £260.00 :o), and whether I could sell on remaining stock to local growers here in the northeast; I wouldn't need more than a couple of bags myself at present.
Our local group has done similar bulk buys like this in the past with composted bark bought by the pallet load and also imported a palleted load of Swedish peat a few years back (and my Shortias & Berneuxias are growing very nicely in a peat block sitting in a tray of water :D)
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Maren
I complained to the company when my stock arrived as the bags must have been filled wet but then stored dry before being sent to me. They replaced all the bags that were short within two days.
Unless you fancy the trip to Belgium you can also collect from Maidstone from Techfill. This quote was two years old but for TG grade it was £0.48/kg.
Techfil (Europe) Ltd
Tel: ++44 (0)1622 717780
Fax: ++44 (0)1622 710551
e-mail: info@techfil.co.uk
Web: www.techfil.co.uk
Peter
The figures of £10 was for sending/collecting one bag via courier. I bought 500kg at £0.52 DELIVERED + Vat which worked out at just over £300. Pumice when dry-ish is two liters per KG. In other words I had 1000 litres of pumice including delivery for £300.
It's the delivery that costs the most, If someone was to collect from Hull in a van or trailer I'm sure the cost of the bags would come down to very little as it's about £80-£100 to have pallets delivered in the UK, so you could take that off for starters.
David
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Aberdeen is so far from everything and yes it's the delivery that puts the cost up on everything but if it's something I need I just try and forget the price and be happy that I managed to get it.
It's just so much easier for you folks down south. :'(
Anyone got a trailer and fancy a weekend break in Aberdeen ::) ;D
David I emailed that company but haven't had anything back yet.
Angie :)
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Don't forget the cost of van hire, diesel etc.etc. Soon adds up. It cost me as much for collecting it as Dave paid for having it delivered. :o
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Ok I have tried a few companies and have had no luck. I got another sample from the first company I tried. They have sent 5-10mm it's looks as if there are lots of sizes in the bag so I think I will just order a few bags and see how I get on.
Maybe if someone has better luck than me they could pass on the information.
One thing I would say is how helpful this company has been.
Angie :)
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Hi Angie,
I'm glad you found something and I look forward to the results of your experimentation. I think I would quite like some of the larger size.
Would it be possible to post a picci of the stuff next to a tape measure/ruler? And how much did you have to pay in the end?
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Maren,
Assuming we're talking about 5-10mm size pumice from Viresco, here's a pic for size information. This is the size that I thought I could break up, so I have two bags full. I think it's a bit big to use as the sole pumice ingredient, perhaps Angie could mix it with perlite.
As I have it available, I'm using it to bulk up orchid composts, but it constiutes no more than about 10% by volume of the compost.
(I have 2x 25kg bags and I'm not using much each time, so there's probably 10years' supply for me. If you want me to send a boxful to try, it won't weigh very much - just send me a p.m.)
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Hi Maren, Peter has got there before me, thanks Peter. I think I little smaller would be perfect but I am finding it hard to source. I was quoted £31 for 25kg bag. I thought I would order two bags, or maybe I could get a smaller size 2-3mm and mix.I was going to mix with a little compost, what do you think Peter.
Since I am here , do I need to pot up my Cypripediums up every year.
Angie :)
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I wish I was still selling pumice at that price! I hope that's including delivery?
I'd get a bag of each and mix.
My preferred mix for Cyps is just pumice and perlite. If you can avoid disturbing for a few years, so much the better but it's a temptation to see how they are doing. The good thing about this inorganic mix is the fact it falls/washes off easily and you tend not to break any roots if you do decide to dig around and have a little look.
David
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Angie,
I was thinking about the pumice sizes that are available earlier - it's better than working ;) - and I would agreed with David that it would better to go for a 50:50 mix of 2-3mm and 5-10mm to provide the inorganic component of the compost. I repot every year, mainly because I have leafmould added (up to 30%) and I find that this will compact over the course of a year so it's a bit inclined to cause waterlogging if left any longer.
David, I assume that you are using only pumice and perlite, with no organic component. I haven't had the courage to do this as I'm sure I wouldn't then feed often enough - although my seedling mixture has less than 5% leafmould, the rest being perlite and seramis (actually Tesco catlitter). How regularly are you feeding the plants?
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Thanks everyone for all the advice. All I need now is to find more room that I can buy some more.
It's really useful to me to find out what others are doing.
I was lucky enough to get good plants from Anthony :D and I feel that I have to make sure I give them the best that I can.
David I hope it was including delivery. Yes that's me. I can never wait, always looking to see what's happening underneath ::) ;D
Angie :)
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Peter
I feed with a weak solution every feed rather than use a stronger one every week or so but give them a flush through with just water now and again. I do the same with Pleione as I find it easier just mixing the soluble Chempak fert in my water butt and using a pump and hose from there on everything. I also use tap water to re-fill it!
Up until last year I was adding some large bark chips to my mix but don't think it has any effect. The best growth has always been in a large raised bed with the pots having holes drilled in the side. I was sceptical about just using perlite and pumice but it works very well and also produces nice clean white roots.
David