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07/02/2013 at 22:17

Just been reading Which? magazine's reviews of the performance of different composts for growing seeds and young plants.

Top is Arthur Bower's seed and cutting compost following by 3 different Verve(B&Q) composts -  grow bag then sowing and cutting then multipurpose. Interestingly and as they say 'disappointingly' all the worthy Best Buy  composts for raising plants in are peat based - though the percentage for each varies!

                                                                                         test score

Arthur Bower's seed and cutting compost is 95% peat                91%

Verve Grow your Own Growing Bag 55% peat                             91%

Verve Sowing and Cutting Compost 75% peat                             89%

Verve Multipurpose Compost  58% peat                                      88%

Any comments, experiences, recommendations?

08/02/2013 at 05:50

Thought peat based compost was a bad thing...?

08/02/2013 at 08:10

There's a long thead about composts, that mentions the Which report, here:

http://www.gardenersworld.com/forum/fruit-andamp-veg/the-best-multi-purpose-compost-this-year/5249-2.html

Lyon Greene wrote (see)

Which? have been researching the issue, systematically. Their results are published in the January/February issue of Gardening Which. I haven't seen the full report, only a summary of their results...

27 brands were tested, for seed-sowing and raising young plants.

Three brands have been selected as 'best buy'. They are all peat-based...

  • Sinclair’s J Arthur Bowers’ Seed and Cutting Compost
  • B&Q’s Verve Grow Your Own Growing Bag
  • Verve Seed and Cutting Compost and Verve Multipurpose Compost.

 

Next, also recommended, though not 'best buys'...

  • Westland Jack’s Magic all Purpose
  • Westland Gro-Sure Seed & Cutting
  • Levington John Innes Seed compost.

 

Best peat-frees, but not as good as the peat ones...

  • Miracle-Gro Expand n’ Gro
  • Vital Earth Multipurpose compost.

 

If anyone subscribes to the magazine they might have some more details, about how good, or bad, all the others were. I don't know which brands came bottom.

But we don't know the details of the tests, nor which brands should be avoided, and why.

08/02/2013 at 20:02

It's a job to know which one to buy this year. If last years examples are anything to go by, I just hope it's better quality, as some of the 'stuff' they called compost was little more than recycled rubbish! 

08/02/2013 at 20:07

agree ddoris. Almost half a brick appeared in one of mine and loads of plastic.  I wonder when the review was done. Until a few years ago I rated Arthur Bowers more highly than I would now.

08/02/2013 at 23:13

A little more detail to answer the questions above - The survey appears in the current Jan/Feb 2013 Which? garden magazine. The survey was conducted from spring 2012 to find the best buy composts for growing seeds and young plants.

They tested 27 widely available composts - 18 peat based, 9 peat free and asked  mystery shoppers to buy them from 4 different regions in the country.

First they tested the handling and texture of the compost for its suitability for small seeds.

They then tried to raise 12 pots of marigolds and basil seeds from each compost ( 3 from each bag bought  from the 4 different areas in the country) Apparently basil does not germinate well if there is a high level of dissolved nutrients in the compost and marigolds will not thrive if the nutrient levels are too low! They counted germinated seeds and the size and quality of the seedlings.

Then they tested for growing on young plants and seedlings - 20 snapdragon and 20 tomato seedlings were potted up in each compost. Again snapdragons struggle if nutrient levels are too high and tomato don't thrive if they are too low. They were grown on without feeding until the largest were ready to be planted out. All plants were rated on size, quality and leaf colour.

They state that although grow bags are not intended for using to raise seeds  they tested them as some people do use them for this purpose as they are so cheap.

Brands tested included Westland, Bulrush, Verve(B&Q) New Horizon, Levington, Miracle gro, Homebase, Vital Earth, Arthur Bower's 

The best peat free compost was Miracle - Gro concentrated enriched compost with  a test score of 73% with Vital Earth  multipurpose compost 2nd with a test score of 65%

Hope this helps

 

08/02/2013 at 23:23

 OOps meant to add - they only gave the results for 22 composts as the other 5 have been reformulated for this year, the ones listed have not.

Bottom on the peat list was Westland multipurpose, 70% peat and a test score of 59% and Verve John Innes seed compost, 50% peat and a test score of 48%

The botton 2 peat free were both grow bags - New Horizon organic & peat free and Verve grow your own peat free - both with a test score of 34%

09/02/2013 at 10:22

Westland (worst MP) is the brand stocked at Wyevale, and some other chains. I've just bought a bag of their John Innes. Their seed compost was well rated.

At many GCs it's Hobsons Choice which brand you get. Unless you're prepared to go somewhere else, which may involve travelling a long way.

I'd really like to see GW cover this subject. Buying compost is an item of regular expenditure for many gardeners and it's important to know if the brand really matters.

09/02/2013 at 11:25
discodave wrote (see)

Thought peat based compost was a bad thing...?

Peat is very good for plants as it soaks up excess water and this prevents plants from rotting, hence it is great for young plants and seedlings.


As peat takes time to accumulate it is seen as bad for the environment to use it, even though it has been used for millenia as heating and soil improvement.

09/02/2013 at 18:59

as a novice veg grower.gonna stick with peat compost

18/01/2014 at 15:16

peat based is the best

18/01/2014 at 15:41

Last season I tried Westlands Jacks Magic, not the cheapest, but by far the best results, for value for money B & Q's verve in the large bale is good value and not full of rotting wood etc., Both are peat based...... "so what!!"

18/01/2014 at 15:43

I bought three grow-bags last year from Wyevale, my local GC and lost all of my plants I went back to them and they weren't very helpful at all so I don't buy from them anymore - I use another GC further away and they offer a bigger range of mp compost...will stick with peat-based I think. Maybe with all the flood water/heavy rainfall last year the bags got contaminated and the stores still sold them when they shouldn't have:/ buyer beware? My local stores have them all stacked outside in their car parks which are often under a lot of water......

19/01/2014 at 11:34

Dont go by Which,last year they said b&q verve was the best,the worst compost I have ever bought.

19/01/2014 at 12:04

I have often thought that one of the problems with the Which? trials is that they are carried out the previous year. So this year they recommend composts that worked well during the last growing season. However what we buy this year may be fresh stuff with slightly different formulations, or old badly stored stuff as mentioned above. Bags of compost are often inconsistent, the QC seems to fail sometimes. It seems to me that it's a gamble on each bag I buy.

I do prefer peat-based but it gives me a guilty conscience!

19/01/2014 at 12:22
"I do prefer peat-based but it gives me a guilty conscience!"

And so it should! I have found to germinate seeds plain coir is OK but you need to prick out fairly quickly. Sometimes I mix in spent tea leaves too.
19/01/2014 at 15:32
landgirl100 wrote (see)

I do prefer peat-based but it gives me a guilty conscience!

Not sure what's happened here but the bit above is the quote - the bit below my comment

I will use whatever gives me the best results, and there are a number of factors which come into that equation. To date I haven't found anything which matches peat based compost.

 

19/01/2014 at 15:46

Wickes sell 70 litre bags for £3 which are 'reduced peat' and I got several bags to improve my clay soil before planting a new hedge.  It had a good texture and no big bit at all.  I haven't found compost cheaper anywhere else apart from council schemes.   I can't say how good it is yet and I haven't used it on seeds/cuttings yet but I will be because it's so cheap.  Online it gets a bad write up because people say it has lots of woody bits in but my bags were all fine.  As someone else says it varies, they can't get the mix exactly the same for each batch but for me I have to find the cheapest supplier.

02/02/2014 at 17:00
Depends which Verve compost you get,the sowing & cutting compost gets a good rating, so does the grow bag but the Verve John Innes no.2 mix gets the worst rating of the lot.
02/02/2014 at 18:50
I have never tried them, I always use Levingtons multi purpose & Levingtons grow bags.
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