Recap and lessons learnt
We didn't really have an idea of how much manure and straw we would need, but as it turned out we needed more than we got. Ideally, we would have liked to have had the heap at least 30cm deep, but it's probably more around 20-25cm deep. As we will need to keep adding to the heap as the potatoes poke up through the top, we're going to need to get much more straw and manure. Total depth will need to be 50-60cm.
While we like growing our own food for the joy of it and also to grow varieties you can't get commercially, we also like to look at the cost breakdown of growing our own vs buying from the local fruit & veg store. For reference, the rough costs:
- 8 bags of cow manure - $44, will need more so add another 10 bags @ $55
- 3 bales of sugar cane mulch - $36, will need more so add another 3 bales @ $36
- 10m roll of chicken wire - $25
- Seed potatoes - $22
- Grow bags - $13
That's a total of ~$230. If we have good yields, that will be ~1kg per plant, so 30kg of spuds. Current spud prices are ~$2-3/kg for bog standard spuds, and ~$4-5 for "gourmet" varieties, so we could grow maybe $90-110 worth of spuds.
However, much of the costs are because we're starting a bed from scratch, which we won't need to do in future seasons as this bed will become part of the rotation. Next season, we will only need maybe 1/4-1/3 of the straw and manure and can use potatoes from this crop as seed tubers for the next (providing no diseases strike the patch). Next year, we could only be looking at ~$50 on materials for $90-110 worth of spuds. We're also not going to get varieties like the Royal Blue or Cranberry Red at the local fruit & veg.In terms of time, the whole exercise took the two of us from around 10am to 3pm (with an hour break in the middle for lunch). The absence of digging meant that than heaviest labour was really moving the bags of manure and strewing them over the bed.