Ralph Martin. Seed raising talk

[Herts Mike]

There is actually a 4 page thread on this subject starting Feb 2015. Can’t give the link I’m afraid.

[el48tel]

There is actually a 4 page thread on this subject starting Feb 2015. Can’t give the link I’m afraid.

It will trundle on .... for ever.

Edit.
It starts earlier than that. And appears in disguises in other threads.

[Nick]

Well i used to douse all my seedlings with Chinosol, but Koehres’ website claims that it is actually a germination inhibitor. However, certainly doesn't lead to complete inhibition, and is probably better than having damping off rampaging thru your babies…..
Now i just microwave

[Tina]

Now i just microwave

me too, with damp compost & baggy method

[Herts Mike]

I stand them in boiling water.

[MatDz]

Ralph, you mentioned using JI ericaceous in the mix instead of the most common JI#2, is that to lower the pH to increase nutrients intake?

[ralphrmartin]

My reasoning was that an ericaceous compost is intended to make the nutrients more available to plants which don't like lime. I'm not trying to changer the pH as such.

[MatDz]

My reasoning was that an ericaceous compost is intended to make the nutrients more available to plants which don't like lime. I'm not trying to changer the pH as such.

Thanks! I think we said the same, just with a slightly different causality order.

[SimonT]

I have looked a bit at the using ericaceous JI for growing seedlings.

Last year I planted two small seed trays with Rebutia (Aylostera) seedlings with my normal compost (basically JI mixed with 1/3 various "drainage" materials) compared to Ralf's lime-free formulation (basically ericaceous JI, mixed with grit and coir if I remember correctly). I was able to get decent plants from both composts! However, the ericaceous compost led to plants that grew significantly larger. It was not just level of hydration of plant from the soil as this difference still holds between plants in different composts even after 6 months of drying out over winter. I tried the comparison with one or two mature plants and this led to the same conclusion. It would be nice to repeat this and see if the same thing happens again. But it does seem useful- I am trying to get plants as fast through to flowering from seed as I can manage- bigger plants are (hopefully) more likely to flower. We'll see anyway- the first buds are forming!

I'm still not 100% sure what causes the difference between the composts, pH, lime or something else. One reason for my confusion is that all non-ericaceous JI compost contains lime(stone) and plants grow pretty well on this. One thing I did notice that the coir containing compost are easier to wet and less prone to drying out. This is well known, especially compared to peat containing composts. But plants need soil to be damp to extract nutrients. So could it be that the coir containing compost just stays damp longer and therefore plants have better access to soil nutrients because of this.

[ralphrmartin]

Thanks for sharing, Simon, most interesting. As you indicate, it is very hard to do controlled experiments where just one thing changes, so you can see what is responsible for the effect on growth.

Using the approach I have outlined, I have had Aylosteras flower in 15 months from seed, although its more typical for them to flower the following year.

The other thing I forgot to mention is that I give my seedlings water through their first winter, which means the roots are in better condition, and the plants less dehydrated, so they are ready to start growth in spring. With the warm weather in the last week or so, it is surprising how they are spurting into growth already - they have now been thoroughly watered using the flood trays a couple of times in the last couple of weeks.