Lettuce pricking out wilting mystery

[dan hazelrowanParticipant]

Well i pricked out my lettuces a few days ago on 3 successive days, the first batch are doing very well, but the next batches have really suffered.  They were pricked out a tiny bit bit late with a small true leaf and roots with side rootlets starting from the main root, but in the past this has never been a problem

On the first blast of bright sun the cotelydons wilted immediately but the true leaf was ok, since then the cotelydons have remained damaged, the true leaf is ok and growing slowly, with another appearing,  but frustratingly for my planting schedule now way behind the first good batch which are racing away,

So I have checked the plants and had a look at the roots, which have basically disappeared! , hence the need for the plants to ditch their cotelydons

What has caused this mysterious root rot – well the variable was I used a new bag of new horizons organic compost for the later prickings out.

The first batch was sown in and pricked out into new horizons also but a a different batch – much woodier, the later prickings out were into a new horizons that was less woody and more sandy it seemed…

So I think the plants somehow have been shocked by the different compost – perhaps the ph is way off? who knows…

Very odd,  I have just pricked out some endive and sown kale into the newer new horizon compost so will have to keep a careful eye

I’ve been really pleased with new horizons this year, the growth has been fantastic in it, so fingers crossed all will be ok , difficult when you are relying on a variable product for important plants

 

[charlesModerator]

Hi Dan, sometimes I get this too, exactly as you describe and it seems linked to age of seed and moisture in the rooting zone, I have added vermiculite to the mix as the West Riding I use is a little dense. Also I water the seed tray as little as possible. However the New Horizon is a lighter texture and has worked for you before. Pricking out early does help, when seedlings are tiny, and it rarely happends with fresher, home saves seed.

[dan hazelrowanParticipant]

It’s interesting and frustrating at the same time – but such is the rich tapestry of salad growing, a fine art, very fine art i would say, and always something to learn, as has been said before

I have resown the lettuces worst affected as a backup, although they are growing, albeit slowly, they aren’t dead, so i view that as a big positive!

I have just pricked out some endive two days ago , smaller this time, and into the same compost and today in the sun they seem fine and are starting their first leaves so all seems ok there

I think a new strategy of mine will be an extra backup sowing one week after the main lettuce sowings, just in case,  challenges have a good side effect of making you learn new tricks and become a better grower – I find that a comforting thought

 

Are you not watering or watering less your compost before pricking out Charles?

[charlesModerator]

I water to capacity before pricking out as it makes the compost soft and it is then quick to make holes, often don’t water for a day or two after that esp if not sunny. The main issue of waterlogging around little roots is not in module trays but in seed trays which drain less well, the ones I have at least. Why not also try direct sowing two or three seed then thinning to the strongest, to compare?

[Eileen44Participant]

Hi Charles
I too have had considerable problems with New Horizon multi-purpose peat free compost. I sowed sweetcorn, summer and winter squash and cucumbers in large modules at the beginning of May. When I opened the bag I knew I was in trouble because the texture was so coarse with recognisable twigs and uncomposted wood about 3cm long. Within 4 days the surface of the compost was covered with a white mould. Later, once the seedlings appeared, tiny mushrooms also developed. The compost holds a lot of moisture and even though the surface may dry out, underneath this crust the compost is very wet.

The plants look pale and puny; the sweetcorn leaves are thin and yellowing at the tips, I don’t think I can use them.
( As an aside: Is it too late to direct sow sweetcorn?)
The squash is also pale and has taken an age to develop their true leaves. Does this indicate a mineral deficiency? This compost is supposed to have enough nutrients for 4-6 weeks growth.

Reading around this subject on the web the common complaint about peat free compost is inconsistent quality and the absence of an industry standard to refer to.
I noticed Charles that you have done several comparison trials on compost in recent times, but if each company isn’t providing the same product from one year to the next the trial results are very quickly obsolete. New horizon MP compost, for example, was reformulated for 2014, which may explain Dan’s problems.
Is there a peat free compost you would recommend?

[charlesModerator]

Hello Eileen,
I am so sorry to hear of your compost woes.
Sinclair who make New Horizon really should do better than this. It grieves me no end when gardeners lose time and even crops, as well as money, with useless composts.
Grrrr.

Right let’s move forward – I like the trials by Gardening Which, who are independent of advertisers. They always refer to what happened the year before so cannot be completely up to date with reformulations and yes, New Horizon is reformulated every year it seems. The contents you describe are just not good enough. Not to mention the lack of growth. I am emailing them at info@william-sinclair.co.uk and it will help if others who have problems let them know, and ask for refund or replacement at least; they need to know.

In the GW trials, their “Don’t Buy” recommendations include Carbon Gold and John Innes no.2.  Their Best Buys all include some peat, mixed with bark or coir, and include Verve (B&Q own brand) and J. Arthur Bowers Traditional All Purpose compost.

For peat free they recommend Melcourt’s Sylvagrow, based on wood fibre and bark and it costs around £7 for 50 litres. The National Trust use this and are pleased with it. I use West Riding module compost which is based on peat sieved from Yorkshire reservoirs, but it is expensive retail.

As for sweetcorn, there is still time in the south of England at least, just and if summer is warm, sow tomorrow!

[dan hazelrowanParticipant]

New Horizons – the woodiness , mushrooms and white mould i have had this year and last also – but with no adverse effects on growth at all , but the new formulation is clearly not quite as good, but endive and kale i have pricked out have not wilted and endive is growing, also extra backup sowing of lettuce , pricked out small is ok too,

Sylvagrow- this sounds interesting, thanks for the info Charles,  would like to try it, nearest place to get bags is Liskeard, 1hr away , so don’t know when i’ll get a chance, so for now might have to make do with NH….  I await any impending tests Charles, perhaps I will order a big load if all looks good

Direct sowing – yes i think I’ll direct sow my radicchios in July, rather than prick out, and then the next lettuce sowing i’ll also try that and then see what does best,

But i guess really we need to be making our own potting composts? I will try that soon also…

[devonstewParticipant]

I’ve been happy with New Horizon this year, last year I wasn’t. The biochar compost was a nice tilth but after germination things just sat there, so where is all the biochar nutrients??

I also had really poor germination in May, and resowed many things, and they all came through great, and so my conclusion was that temperature was the key factor.

Cheers Stew

[Eileen44Participant]

Hi Charles,
Like other brands of peat free compost the bulk of NH multi purpose is ‘ composted bark and timber residues’ with the addition of some minerals and a byproduct of sugar-beet processing called Vinesse, which is I think a source of nitrogen.
When making my home compost the wood is the last to break down and locks in nitrogen from the surrounding materials to aid its decomposition. Can I assume that the same action is taking place with the twigs and pieces of wood I find in peat free compost? I wondered if this robbing of nitrogen might have contributed to the poor development of my seedlings.

Also, the garden centre where I purchased my NH compost don’t store it undercover and it had been raining for 3days and the compost was very wet. Could any water soluble nutrients have been leeched from the compost?
When I returned the 2 remaining bags of NH multipurpose compost I replaced it with 2 bags of Arthur Bowers seed and cutting compost which I also had to return because it was so wet I could have squeezed the water out of it.
So maybe the source of some of my problems lie with the retailer.

I would like to make my own seed sowing medium using my own compost and other ingredients but I don’t know how to overcome the problem of weed seeds present in my compost. Any suggestions?
I have a large amount of 2 year old leaf mould and came across a recipe for seed compost by layering up comfrey leaves and leaf mould, setting it aside for a couple of months to rot down. Do you think that’s viable?
Thank you very much for answering this beginner’s queries.

[charlesModerator]

Nice comment, helps to get a better idea of what is going on. Another issue is that here is a possibility of some stockits selling last year’s compost.
Its certainly true that warmth plays a key role and that is the nice thing about sowing anything over the next few months, seedlings appear almost overnight.

[Eileen44Participant]

Hi Charles,
Like other brands of peat free compost the bulk of NH multi purpose is ‘ composted bark and timber residues’ with the addition of some minerals and a byproduct of sugar-beet processing called Vinesse, which is I think a source of nitrogen.
When making my home compost the wood is the last to break down and locks in nitrogen from the surrounding materials to aid its decomposition. Can I assume that the same action is taking place with the twigs and pieces of wood I find in peat free compost? I wondered if this robbing of nitrogen might have contributed to the poor development of my seedlings.

Also, the garden centre where I purchased my NH compost don’t store it undercover and it had been raining for 3days and the compost was very wet. Could any water soluble nutrients have been leeched from the compost?
When I returned the 2 remaining bags of NH multipurpose compost I replaced it with 2 bags of Arthur Bowers seed and cutting compost which I also had to return because it was so wet I could have squeezed the water out of it.
So maybe the source of some of my problems lie with the retailer.

I would like to make my own seed sowing medium using my own compost and other ingredients but I don’t know how to overcome the problem of weed seeds present in my compost. Any suggestions?
I have a large amount of 2 year old leaf mould and came across a recipe for seed compost by layering up comfrey leaves and leaf mould, setting it aside for a couple of months to rot down. Do you think that’s viable?
Thank you very much for answering this beginner’s queries.

[charlesModerator]

That is a good point about the sacks lying wet which certainly could be the problem if it lasted a while. Comfrey with leafmould sounds a good idea, few weed seeds. Some people advocate cooking the compost to 60C in a low oven to kill weed seeds but I feel it kills too much else, so I have no answer except lots of weeding. Maybe sow into bought compost then prick into your own, plants are then two leaves ahaead of the weeds.

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