Compost choice & mildew - advice please

[hellohelenhere]

I've been using multi-purpose compost for my cuttings & plantlets. The Peat-free multi-purpose from thecompostcentre.co.uk is nice and open, but a little bit fibrous, so I wonder if it really makes good close root contact. Other stuff, that I got from Focus, is rather dense and I fear it may get a bit cloyed with moisture.
Both types are suffering with a mildew problem in my lean-to - almost everything seems to get a white fluffy mildew on the surface of the compost, though I've been very sparing with watering. Perhaps I watered in too much when planting? It doesn't seem to be very harmful to the plants, they look OK, but I wonder if it stresses them?

As for seeds - will they tend to rot, in these conditions? Should I pay more for potting compost, specifically? (Peat-free, though, as I don't want to use peat.) Or in the high humidity of the Thames Valley in February, is it just one of those things?

[hellohelenhere]

[SMP1704]

Hi Helen

I have used both multi purpose and seed compo.  Now it may just have been a bad year, last year, but I had a lower germination rate with seed compo than with seived multi purpose.

How often are you watering?  My approach is to fill the pots/trays/whatever, then give the soil a good soak, let it drain and then sow the seeds.  I don't water again until I transplant them.

Some of my pots get a bit of white mould, but it never seems to bother the seedlings.

Hope that helps.

[hellohelenhere]

After watering the cuttings in, as lightly as I could manage, I haven't watered again till the pots feel light, so barely if at all, in some cases. I guess it's just bound to happen in the present humidity - I'm relieved if it's normal and doesn't hurt the plants. They don't seem unduly bothered.
I might stick to mixing the fibrous stuff with the dark fine stuff, and hopefully should have a mixture fine enough to make contact and loose enough to aerate well.

Will follow your watering strategy for the seeds - thanks for the tip. :)

[Tee Gee]

I've been using multi-purpose compost for my cuttings & plantlets. The Peat-free multi-purpose from thecompostcentre.co.uk is nice and open, but a little bit fibrous, so I wonder if it really makes good close root contact.

Other stuff, that I got from Focus, is rather dense and I fear it may get a bit cloyed with moisture.

This info might help; http://www.thegardenersalmanac.co.uk/Data/Compost/Compost.htm

Both types are suffering with a mildew problem in my lean-to - almost everything seems to get a white fluffy mildew on the surface of the compost, though I've been very sparing with watering. Perhaps I watered in too much when planting? It doesn't seem to be very harmful to the plants, they look OK, but I wonder if it stresses them?

I think you mind find this is partially down to ventilation or should I say lack of! particularly if you have got heat on the go.

Balancing heat & ventilation can be quite daunting.

As for seeds - will they tend to rot, in these conditions? Should I pay more for potting compost, specifically? (Peat-free, though, as I don't want to use peat.) Or in the high humidity of the Thames Valley in February, is it just one of those things?

The compost you use is unlikely the cause here, plus I would say forget about the potting compost issue at this stage.

Potting composts have a higher fertiliser content than seed composts and seeds don't need fertiliser! after all they have no root system to take up the fertiliser so why put it in.

As you will see in the link I have attached  I even weaken the fertiliser content of multi-purpose compost such are my thoughts on this subject!

The fact that you mention 'humidity' makes me think you too are concerned about the damp atmosphere in your lean to and until this is addressed you might still have problems.

You could try this; Fill your tray with the compost of your choice, soak it, let it drain, then sow the seed onto this then cover with a sprinkling of compost direct from the bag but dont water it.

This will create a dryer atmosphere where it is needed most.........at seed level.

[hellohelenhere]

Thanks very much for all that, Tee Gee. I've used your suggested method to plant seeds this week. I don't have heating in the lean-to, but it doesn't have ventilation, except when I open the exterior door - so I'm trying to do that more often. Thanks for all the info about compost.
cheers,
H