Getting To Grips With Coir - Elixir Garden Supplies

Getting to
grips with
Coir

Coir compost in a block is extremely useful, better for the environment and can produce great results.

Chris, one of the Elixir Gardens gardening team has been trying out our coir blocks and fertilisers.

Check it out below and view all related products at the bottom of the article.

Reasons to make your own compost

When I first became interested in horticulture as a teenager I soon started to develop my own compost mixes. I was quite happy getting to grips with making my own compost recipes for a range of crops from tomatoes, to bedding plants. Originally cost was the major factor to ‘mix your own’, but over time prices for bagged compost have fallen significantly. Being mainly peat based the quality was perfect for what I needed and subsequently my time was better spent on being more productive elsewhere in the garden.

Times are changing though, and peat use in composts will be banned in a couple of years’ time. The days of good quality compost on three bags for a ‘tenner’ are now a thing of the past. As I use a lot of compost each year the search for alternatives is now more important than ever.

So, I found my old compost recipes! After a bit of revision I decided this year I would experiment with a number of mixes for growing tomatoes and peppers. I thought it would be good to take a look at what I could achieve with either a straight coir composts and a coir/compost blend.

So why coir?

Having used 100% coir for around 20 years in a proprietary multi-purpose mix for all the vegetable plugs I produce, I actually prefer it to peat based composts, I feel the open texture of coir means the compost is better aerated, and with air getting easily to the plant roots equates to more root mass and much faster growth. Despite what is often written I find coir drains really freely, which is a big bonus early in the season as too much moisture can lead to many seedling diseases.

But the potting composts I have used until now have been 100% peat, hence the search now for viable alternatives.

Available from Elixir, I am using coir blocks which each make around 60-70 litres of compost. For one mix I will use the fertiliser supplied with the coir and for the other I will use Elixir Gardens’ EX4 Fertiliser at a rate of 5 grams per litre of compost.

Lets get mixing

Before you start you will need watertight containers to mix the compost, and after fixing the leak in the wheelbarrow I was ready! In the wheelbarrow I put 23 litres of water and in the black container 21 litres. I then mixed the coir fertiliser with a further litre of water and rinsed the jug with another litre making the total up to 23.

I unpacked both coir blocks and put them into the containers

As I had not done this before I really did not know how long the process of re-wetting the blocks would take, in the end with a bit of help breaking up the block it took around 40 minutes to absorb the majority of the liquid up.

After a further mixing around by hand the coir now started to look a lot like the familiar product I use, the blocks broke up easily and were of good structure, not too fine or too coarse.

Testing the pH

The pH of compost is particularly important to ensure adequate availability of nutrients, peat is naturally acidic and has to have lime, usually dolomitic lime added in various ratios to the type of compost you are producing to bring the pH up to around 5.5-6 . Coir on the other hand is said to have a pH of around 5.5-6. As I had never made compost with coir before I wanted to check this to be sure.

A very quick way to do this without reverting to expensive meters is to use a litmus paper and compare to a pH chart. Top left is ‘hard’ tap water and bottom left rain water, you can see quite a difference between the two.

However, the two samples on the right are from each batch of compost which shows a pH of 6-7 which although perhaps a little higher than I would like are certainly out of the ‘Red’ zones which are a problem for anything except ericaceous plants and would need to have additional lime added.

Adding extra nutrients

EX4, Elixir Gardens own base fertiliser, has an NPK of 5-7.5-10 plus Te and should be added at 5g per litre of compost. I used 300g for the 60/70 litre block which I mixed in thoroughly to ensure even distribution. EX4 is a complete base fertiliser and will supply all the nutrients the plant needs during the establishment phase. Tomatoes will need additional nutrients from fruit set to ensure high the high demands of this crop are met.

Although I’ve used rates of nutrition from established peat based composts I wanted to see how it works with coir. Using 5g per litre of compost is a higher rate than you would usually use. It is ideal for demanding crops such as tomatoes and hanging baskets, where the demand is instant. The usual pricking out/potting rate is around 3g per litre of compost, and sowing is at 0.5g per litre.

If you choose to add a controlled release fertiliser to compost you should also reduce the amounts of EX 4. My preference is to avoid the use of controlled release fertilisers on tomatoes. During a warm spring they can release far too much nitrogen resulting in plenty of vegetative growth and few fruits.

Ready to get planting

So there you have it, the finished product ready for use straight or as a component of a blend. Keep checking our social media for updates on all the flowers and veg I have planted.

I’m based in Shropshire, and I’ve been a keen gardener since childhood. Throughout my career I have raised plants commercially, landscaped gardens, taught horticulture, built the odd show garden and managed public parks where I helped popularise the use of wildflowers. My passion has always remained with growing fruit and vegetables in my own garden and looking after my rare breed chickens.
Chris