Cheap potting mix nitrogen blues

in HiveGarden2 months ago


'When I was a boy' (I get great amusement saying that of late) cheap potting mix and a bag of wood chips were different things. Now, though, there doesn’t seem to be much of a difference…

The problem with buying the cheapest potting mix (I’ll not name the brand pictured, it's a common thing) is that it’s mostly wood chips. When you plant into it, the microbes that find themselves there take easily available nitrogen out of mix in order to break down the wood. That means that there’s less for the plants and their leaves go yellow.

Nitrogen is a crucial nutrient – it is used to make proteins, including the enzymes that bacteria use to break down nutrients into plant accessible forms. It’s most important role, though, is that it is part of DNA and RNA, without which, growth and life itself is impossible.

Lack of nitrogen shows itself as yellowing in the older leaves at first, as the plant reclaims it and moves it to new growth. Eventually though, a long term deficiency will yellow the whole plant. Because of this, nitrogen is called a 'mobile' nutrient. Iron is another mobile element and deficiency of it causes similar symptoms.

The key when using this kind of cheap potting mix is the same as when you’re using woodchips as mulch. You need to add a nitrogen rich fertilizer such as dilute chook poo, Blood and Bone or even dilute urine before you use the mix. That’ll add the nitrogen needed to break down the wood and leave enough for the needs of the plants that you plant into it.





Oh, my. I have never seen that type of potting soil. Thank you for the warning. I usually love to buy soil because, as they say, "It's dirt cheap" and you leave the store with a huge bag. It's kind of gratifying compared to a drug store where you pay too much and walk out with a tiny little bag.

There are plenty of potting mix and soil brands and varieties, some good, some bad. The trend towards more, poorly broken down woodchips continues though, at least in South Australia.

That single component is really needed in order for our plants to grow well.
One must have a proper knowledge when using thise cheap wood chips so that everything will go right and will not blame those wood chips for killing their plants.

That's true. Some folks can't afford the good stuff, so the simple action of adding some nitrogen (which is freely available) can make the worst stuff passable.

That is very true.. Those products can't be help sometimes.

How interesting, I don't know if but here I think what you are talking about is called acerrin. Yes, I have seen how they put it on the silvers.

Yes, acerrin or 'sawdust' as we call it is commpnly used too.

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Thank you for sharing the post.