Grow with a Pro, September Edition
2nd Sep 2022
Overview / what’s happening this month
Last month in my Winter Gardenz greenhouse, I planted a range of leafy green seedlings and it took only 2-3 weeks to start harvesting these daily. Growth rates have picked up even more the last fortnight (it’s been very mild here) and I am enjoying a daily salad or two of lettuce, parsley, coriander, celery, kale, silverbeet and corn salad.
I slashed the autumn green manure crop after just 5 weeks and dug this in. I noticed absolutely no nodule growth on the root system of the peas which was a bit discouraging, but I likely did not leave this anywhere near long enough for rhizobia to colonize the root system and start fixing nitrogen (or perhaps a deficiency n molybdenum and/or cobalt is the problem - more on that in a later post).
Lupins and vetch are far better Nitrogen-fixing performers in my experience so in future I’ll go back to using these (I’ll explain a lot more about the Nitrogen-fixing process and why nitrogen is such an important element in a future post).
I’ve planted cherry tomato and spinach seedlings amongst this dug-in green manure. I added a load of worm castings and organic compost to this bed too. It’s warm enough here now to plant tomatoes inside and I’ve chosen cherry because they mature / fruit quickly (meaning I’ll have tomatoes within 5 weeks hopefully!).
Note: these seedlings I bought from Mitre 10 and prior to planting I dip the plant in water to wash any artificial fertiliser which I don’t want to introduce to my organically managed beds.
A comment on the Waikato topsoil I bought in to build the beds up.
It’s been so finely sieved there is little to no crumb structure left and it has a feeling of being very ‘devoid of life’.
It is a great free-draining medium but requires a lot of organic matter to bring it up to scratch. I’d much rather do this though than use any of the ‘garden mixes’ at commercial landscape supply yards which I find to be generally of poor quality and like much non-organic compost, crammed full of undecomposed bark filler. (continued...)
Next month I will be covering some aspects of soil science in relation to plant health in the greenhouse. I’ll give some tips on organic matter, nitrogen and nutrients. We’ll also discuss how glasshouse growing turns over organic matter and takes up nutrients more quickly (so the soil has to be fed more often). We’ll also be discussing intoxicating (more accurately, eradicating) slugs with beer traps. Unfortunately, the slugs won’t likely be performing any drunken karaoke from the beer traps, which would be quite entertaining, but the beer traps are an effective method of eradicating the little pests.