I often buy compost in 40litre bags to supplement my home-made efforts which costs about $5 a bag, but buying in bulk is much better value especially if you’ve got a few bigger jobs in mind to do. So in case you’re wondering why I have to buy it when I talk so much about making my own, the point is, I find my efforts at making compost are still not producing as much as I need for those bigger jobs.
So I got a half metre each of compost and garden mix which cost $114. They both look much the same because the garden mix has a certain amount of compost already in it, but you can plant directly into it. The compost on the other hand, is a much stronger mix and shouldn’t be planted into directly, but it’s great for rejuvenating the soil.
In addition to the 2 trailer loads of ‘soil’ I stopped in at Bunnings and got an 8kg bag of coarse pumice ($14) which can be added to the garden mix to make it more suitable for potting. The pumice helps to improve drainage and it also helps to aerate the soil.
While I was about it I couldn’t resist this bright pink Azalea which reminded me of one I had some time ago but which died on me. This was in an 8cm pot and cost about $9. So this was my first little potting job using this new mix.
I’ve got a few other jobs planned too, but more about that later.
From an economics point of view the photo below shows 4 x 40litre bags of compost next to my bulk compost which cost $57 — half of the $114 I paid in total. The bags cost $5 each so if you can imagine a pile 2.8 times this size, that would cost the equivalent of $57 the same as what I paid for the bulk mix. Based on this estimate the bulk mix works out about half the price or a little bit more.
This isn’t as good a value as I recall from 20 odd years ago but it still works out cheaper than the bagged stuff and well worth buying it this way if you’ve got a few bigger jobs to do.
A 40 litre bag of potting mix costs between $10-20/bag depending on the quality, so buying it by the bag can be expensive, especially if you need several bags. That’s why I buy a load of bulk mix every year.