Why do B&Q etc have alpines 9cm in peat sand multi-purpose?

[newstart]

When I go to a garden centre or B&Q why are the alpines always in a multipurpose peat sand mix(assuming thats correct ?). Is this because they initially grow faster at this stage in a freer draining mix etc etc.

I just wondered as you always see this done and if plants will grow quicker initially.

I finally have a nice size greenhouse put up- its really good and will be an excellent help!

Thanks David.

[iann]

You should see what they have their cacti and Lithops in   Soil guaranteed to kill a plant within a year, which I guess they don't mind so much.  The peat mixes are cheap, light, consistent, and they work very well for short periods of constant growth in controlled conditions.  Of course once you get them home, assuming they're still alive after a month of abuse in the warehouse, you can't get the peat wet again and you can't get it off the roots to put the plant in some real soil

[newstart]

Thanks Iann. I had assumed it was for quicker initial growth also. Is it also because the the mix is lighter for roots to develop faster in the first month of being potted(after which a quick deterioration). I say this because if you wanted to develop roots faster and then pot on into a 1 litre pot for example after this may be the way to go?

Also are peat based mixes bad for over wintering newly potted plants when growth is slower(hence peat not so bad then) ?

Anyone else had experiences they would like to share?

David

[Maggi Young]

A peat/sand (50/50) mixture has been a  common compost recipe for seed sowing and potting on for donkey's ages. Unless a plant has a great aversion to a slighty acid mix then most things will make a reasonable start in that mix.

Peat is relatively cheap; easily packed ,compressed in bales and  stored ; lightweight and clean an easy to handle: these are all points that make it attractive to growers for potting up.
 From that list it is clear to see the advantage for a grower to use peat . It will provide a decent plant in a short time to grow on to point of sale.

But there is little nourishment in such a mix, beyond any feed that may be added as an extra and the problems begin when those are exhausted , should the plant still be in that mix.
From the growers'/sellers' view, by that time the plant is long gone from their premises and the problem is the customers, not theirs!

The problems of drying out of a peaty mix have already been stated. And these problems are quite major.....  the plant can end up being a prisoner in the peat!

If I buy any plant in a peaty mix then I will try to wash off that mix as completely as possible before either planting out or repotting the plant.  There are very few plants that will thrive long-term in such a mix and it is hard for roots to make the transition from such a mix into any other mix that surrounds a peaty rootball.

So, from a  seller's side, peat mixes are very useful and from the customers' side,
probably less so! 

[newstart]

Superb answer Maggie thanks! In terms of speed of growth would you say in your opinion that a loam john innes and peat mix, half and half , would grow just as quickly as the peat mix commercial growers use ?

Just to say I understand about John innes being best( from 6 months ago when I had asked before). Didn't want u to feel I had not listened previously. Saves u time in answering me.

Hope things are well for you! I have now got decent 6 x 12 greenhouse. I was struggling with other structures before this.

Thanks for the info. it always very useful and informative and appreciated.

David.

[Maggi Young]

David, it will be so much easier for you in many ways with a greenhouse to work in.... if only to keep YOU dry when it rains!! 

 Yes, I would choose a  john innes and peat mix over a plain peat or peat and sand if that were my options.

We tend to use our standard potting mix for  pretty much every plant and seeds, cuttings, growing on, with only different nutrients added for bigger, more hungry items. That mix is two parts sand two parts 6mm grit one part leafmould. 

Fine seed being sown would get a little extra leafmould . Bigger plants needing fiercer drainage get more grit... that sort of thing.

[newstart]

Very helpful thanks. Just to clarify from my other question- Would this mix you mention or the peat/loam cause the plant to grow as quickly as a peat/sand commercial mix in the early stages. That's the real answer I am after so to speak. I do indeed have the green house put up now-its excellent and indeed does keep me out of the wet. Its a 12x6 as i say.

Thanks that should finish up.

David.

[Maggi Young]

I cannot answer your question with any certainty, David, since speed of growth as such is not something that particularly bothers us, we're more concerned with seeing top growth that is commensurate with good root growth, for a long term healthy plant. If that takes a  wee while it's not a problem for us.
You would need to do trials with the different mixes side by side with the same plants in each at the same time to see what happens.

Most plants are so programmed to grwo and survive that initial growth rate will  probably be pretty even over different mixes... how a good permanent root structure develops and what ease there is of transferring the growing plant to a completely different substrate is another matter, as I already said.

[newstart]

Thanks Maggie. Thats a very helpful answer I shall try them both. Cheers.

[iann]

Availability of nutrients will affect the growth rate of small seedlings even when they still have cotyledons.  Peat is pretty good at storing and supplying nutrients and can make it easier to get optimal growth with less than optimal fertilising.  Sometimes more than optimal growth!  Gritty loam mixtures may not provide a sufficient steady supply of nitrogen in easily digestible nitrate form.  Think about adding very dilute fertiliser each time you water your seedlings, a quarter of the recommended dilution or even less.

[gote]

Many years ago I bought plants from Sündermann in Lindau. These were excellent but I had problems in growing them on. Sündermann are not the kind of people wo sell at garden ceters and the potting mixes were intended to keep tle plants well in Lindau. However, I found that if i immediately potted on in my own mix, I had excellent results. I think the moral is that what works well in a specialist nursery in a different climate and a different kind of care might need to be exchanged for what works well in your own situation.
Cheers
Göte

[newstart]

Thanks Gote for your answer. David.