Composts again

[Eric Williams]

Years ago most cacti were grown in JI 2/3 plus grit I assume. Along came Tescos finest, and I wonder how many growers use it ?
What does it actually do ? Does it help drainage together with retaining water and there is the weight factor too ? Thanks

[el48tel]

We had a "bring a plant and pot it on" session in Manchester at the weekend. Surprising how many different variations on the compost mix. But the concensus is .... low on organic matter ie Ji component from about 15 to 30%. Similar amount for grit ... chicken or potting or granite. Rest is molar clay and Perlite or pumice. And .... lighter and fluffier the better.

[Bonsai2]

It is fascinating to read of the different mixes used by growers. I have just finished moving my collection of Mesembs (200) including Conophytum, Lithops, Gibbaeum, Faucaria and Stomatium from the peat free JI2 which I found to be rubbish from 5 suppliers to 100% pumice using 1-3mm for seeds and young seedlings, 2-5 mm for most of my adult collection and 3 - 7 mm for my larger Cheiridopsis plants. They are all fed with a natural feeder (Maxicrop seaweed plant stimulant), at 1/4 strength on a monthly basis during their growing seasons only and all are doing well. While the pumice is more expensive than traditional substrates it is 100% reusable for repotting after rinsing and allowing it to dry.

[Ernie]

Just to be a little argumentative; Today I was at a well know national garden centre and noticed all the cacti and succulents recently added to stock are all looking well growing in a peat based compost with little or no drainage in plastic plots. A common practice by the Dutch growers who produce millions of well grown plants. (what happens to them after they arrive in garden centres and super markets is another matter). Who is wrong?

[el48tel]

Just to be a little argumentative; Today I was at a well know national garden centre and noticed all the cacti and succulents recently added to stock are all looking well growing in a peat based compost with little or no drainage in plastic plots. A common practice by the Dutch growers who produce millions of well grown plants. (what happens to them after they arrive in garden centres and super markets is another matter). Who is wrong?

Peat ...
It's predictable in its fluid uptake especially where the growth is of hundreds sitting side-by-side in a controlled environment. Lightweight to keep transport costs low. Allows rapid growth.
Cheap.
The product.
The grower couldn't give a damn. Once you've bought it, it becomes your problem. No guarantee ... no refund. And you'll go and buy another because you'll be clueless why it died. Win win.

[Eric Williams]

I agree with Ernie, Dutch growers use a compost that starts a plant off very well,but general agreement with people in the know will put the plant into a longer lasting and more agreeable compost.
My take on it is a compost will hold a plant into its pot.( C&S need a bit of drainage) say grit. From then on I believe feeding to be the most important next move. Cheers

[SimonT]

I still use a JI based compost with about 1/3 drainage. I'm not growing plants in a greenhouse so flooding pots when
watering is something I need to avoid. So I'm not too keen on mineral composts. Getting a good JI substitute that is peat free is still a challenge though.
Biggest step forward for me would be composts with the ingredients written on the bag- then as a consumer I could pick the
product I wanted to buy.

[Eric Williams]

Slightly off thread,but has coir been found to be a successful alternative to peat? Thanks

[Herts Mike]

Do you have any difficulty watering pumice?

I switched to cat litter for a season but the water just ran through. I don’t have the facilities to stand them in trays.

[MatDz]

Slightly off thread,but has coir been found to be a successful alternative to peat? Thanks

Pine bark is certainly a promising peat alternative for some of the carnivorous species, mainly Sarracenia I believe. It might work fine for c&s? https://melcourt.co.uk/products/growbark-pine/