Growing Media for Trees

Tree Nurseries
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There is a huge range of options for growing media to use for trees, either in a professional tree nursery, or for growing smaller amount. Hopefully this discussion can help you decide which to go for.

This is a wiki post which can be edited by anyone. Go to the discussion page of the topic and click :memo: Edit to update it. Use edits to change the factual content of the page. Use replies to the discussion to add your opinions and experiences!

The topic of growing media is strongly linked to that of feeds and fertilisers. We will keep the two topics separate for now. A future topic on feeds will hopefully be added soon and linked here.

Intro to Growing Media

First let’s set out what we mean by growing media. In the UK (and only here, apparently) we confusingly use the word “compost” to describe two completely different products:

  • True compost is made by a “composting” process and contains high levels of micoorganisms. It can be used as a top dressing or fertiliser. It is far too rich to use alone as a growing media!
  • Compost can also mean a growing medium. This is the type you buy in the garden centre. It is meant for raising plants and seedlings, potting mix etc.

This video, by Farm Advisory Service Scotland and Audrey Litterick is well worth a watch to understand more on the subject and what makes a good growing media.

In this topic we are concerned with growing media.

Commercial Products

Listed in alphabetical order. When adding new products to the list, try to match the existing formatting by including what they are made from, and where to buy them. Only include products that are available to buy in Scotland and can be delivered here. A big issue for us in Scotland is delivery costs, particulraly for Highland & Islands growers so links to suppliers that deliver Scotland-wide are appreciated. If a section specifically on delivery companies is needed, then add it.

This section is focused on trade suppliers of bulk deliveries. Some products are available in small quantities from specialist garden centres but will be a lot more expensive.

Please add your personal experience of these products below as replies (not in the list itself).

Dalefoot Composts

Without doubt one of the most sustainably made growing mediums on the market, Dalefoot have received a lot of publicity in the gardening world with 100% UK sourced ingredients and organic certification. However they say their products as too “rich” for growing trees in neat, and suggest mixing with a lower fertility product such as peat, coir or compsted woodchip. So, not a tree growing media in itself, but maybe of interest for those looking to create a mix.

Melcourt Sylvamix / Sylvagrow

Melcourt make a range of peat free growing media for nurseries and retail. The Sylvamix Nursery Stock is the one widely used for tree nurseries and there is an organically certified version. It’s available in 50L bags, bales or bulk (although we only know of bagged suppliers in Scotland).

Moorland Gold

Moorland Gold is not peat free, but the peat used is naturally filtered from reservoirs. They have a range of different products available in different packaging, including plastic free bulk options. Many growers have not been convinced by other peat free options, so Moorland Gold can be an option to still include some peat in the media but in a sustainable manner.

Retail “Composts”

There are a vast array of retail composts available at garden centres and online. Some are peat free and others still contain peat. Many of these are suitable for growing small numbers of trees and can be affordable options, but there is often a large degree of annual variation in results as their ingredients can change. These composts (particularly peat free ones) contain green municipal waste that varies massively in quality - some even contain bits of plastic and chunks of wood! Comments below are welcome on these if you have used them.

Additives

Although many of the media above can be used neat, many nurseries add their own additives to change the properties of the medium. Some that are used are discussed below.

Vermiculite

need info!

Sand

need info!

Soil

need info

Biochar

need info

Homemade Options

We have a huge resourse in Scotland of potential ingredients to make our own growing media. Use this section to add your experiences and mixes.

Composted Woodchip

Woodchip has a huge potential for locally made growing media. It can be made yourself from any tree waste and a decent hired or bought chipper. It generally takes 2 years to break down enough to be used as an ingredient and is fairly low in fertiity. One interesting farm uses it for all of their fruit & veg growing media and have done some excellent scientific trials. There is potential for small to medium tree nurseries with adequate space to grow biomass specifically for woodchip production (short rotation coppice or hedge management) and further trials and research would be very welcome. There is a book on woodchip if you are interested in finding out more.

In more built up areas you may be able to get local tree surgeons to drop woodchip for free at your nursery. Most chip is suited to making compost if left long enough but it is best if the conifer component is kept under 20%.

One concern is the transmission of tree diseases through the media, particularly if the source of the chip is not known. Conversely the presense of huge amounts of fungal and microbial activity is likely to have positive effects on growing too.

Composted Bark

Many commercial mixes use composted bark, and this may be an option, particularly if you have commercial forestry businesses nearby.

Composted Bracken

There is no shortage of bracken in Scotland and it is relatively easy to harvest, shred and compost. It makes a good base substrate and this article by Forest Research is worth a read, and this article by Sycthe Cymru on general use / cutting info.