Tuesday, 8 September 2009

Say no to moss, yes to coconut


At the Botanic Gardens we stopped adding moss peat to our potting mixtures more than 15 years ago. Instead, we generally use ‘coco peat’ (or ‘coir’), made from the husk of a coconut and readily available as a by-product of the coconut industry, as well as composted pine bark.

A study just out from Italy gives the thumbs up to coco peat, although they still mixed in a little of the moss peat.

Classical peat is good addition to a potting mix - retaining water and adding extra nutrients – but its extraction from the wild is generally unsustainable. Note that I understand harvesting of living peat moss can be sustainable under certain circumstances. The dry moss peat is formed when the moss sphagnum and other bits and pieces partly decay in swampy land called peat bogs.

To extract the peat these wetlands are drained and destroyed. In addition to the environmental impacts, peat is now becoming difficult to source and expensive.

So the researchers from the University of Turin tested five different peat substitutes, mixed with some standard peat, and found that coconut fibre was the best.

They used camellias as their test plant because they grow well in acidic soils and are often grown in pots. (If you are interested, the cultivars were ‘Charles Cobb’s’, ‘Nuccio’s Pearl’ and ‘Dr Burnside’.)

They tested green compost (grass clippings and leaves), pumice, fibre from coconut husks – composted and uncomposted, and pine bark.

Each of the alternatives was as good as, or better, than straight moss peat, except for the green compost which raised the pH of the mix. Coco Peat was recommended, with some adjustment to fertilizing and watering compared to straight peat.

If you use coco peat straight, you would definitely need to add a little something for you plants to live on.

Image: Coco peat, from a supplier site

7 comments:

Jim said...

I have cut back on cocopeat in favour of commercial composted pine bark and similar (don't use peatmoss for ideological reasons). Found it to be too 'strong' for seedlings and young plants and read that the sodium content was very high and toxic to a number of species. Another problem I found with mixes for succulent plants is that its ability to hold water was a bit too good and I lost a few things. Not saying don't use it; just be careful with delicate things and do not get too carried away with a good idea... :)

Tim Entwisle said...

Thanks Jim. I gather the degree of composting of the coco peat might also be important. It was interesting that the Italian experiments didn't use anything on its own but kept some moss peat in every mixture. Obviously the ethics/ideology not as strong.

Chris said...

I'm very new to this peat moss thing. I thought it was just some sort of hay before. So let me ask what may be a silly question. Can't we use basic composted material for potting?

Tim Entwisle said...

Depends what you are trying to grow. Soil or regular potting mix will be fine for a lot of plants, but a material like peat moss or coir has great water holding capacity and helps improve the texture of heavy soils. It also suits certain plants, particularly those that aren't usually rooted in soil (e.g. epiphytic orchids, growing naturally on tree trunks or rocks).

Chris said...

Well the plants I'm interested in are probably not even high maintenance. I'm into planting mangoes, mums and probably a couple of fruits.

Coco peat supplier said...

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Thanks & Regards Coconut Fiber Supplier

Harish Coconut Products said...

Thanks for sharing informative post! Yes coir fiber is environment friendly and also it has plenty of uses.