On 21/05/19 12:26, Nick Maclaren wrote:
In article ,
Jeff Layman wrote:
On 21/05/19 10:03, Roger Tonkin wrote:
I was clearing the tubs that help the spring bubls and putting
the used copmost on the veggie patch.

SWMBO asked why I did not use it again, rather than buy new.
Tactfully explained that all the nutrients would have been used
up by the bulbs and if she wanted a good displaing plants this
year it needed fresh soil. Her response, well why don't you
just add the nutrients, you've got a big bucket of Growmore in
the garage!

I wonder - is she right?

Yes.

A handful of Growmore, or a slow release fertiliser like Osmocote should
see you ok for next year. I reuse everything - from compost in pots,
seedtrays, plugs, etc. Maybe add a bit of fertiliser if I remember, or
some new compost. And I never wash old pots - I just brush them out with
an old washing-up brush (and no, I don't put it back by the sink after
use!).

No, Growmore alone will NOT work - most especially not on 'soilless'
compost. It is a NPK fertiliser, and the compost will be depleted
of many of the other nutrients. Miraclegrow and other 'complete'
fertilisers will work. I don't know what Osmocote contains.

I hardly use any fertilisers at all, and never bother with trace
elements (other than iron sequestrene for ericaceous plants where
necessary). About 35 years ago I started to grow Western Australian
plants, and got an assortment of chemical fertilisers from Chempak to
make my own composts, especially those necessitating a very low level of
P. I also got a pack of "Trace element frit" - a fairly fine powder with
a mix of TEs to add to any compost. After opening it to see what it
looked like, it remained unused, as did most of the other "specialist"
chemicals. In the end I settled on a mix of peat, sand, and ericaceous
JI - 1:5:1 for seeds, and 1:3:1 for growing.

Maybe something more than Growmore is required for decent cropping of
food plants, but I've never had an issue with not using NPK+TE fertilisers.

For info on Osmocote, see he
https://icl-sf.com/uk-en/explore/nursery-stock-perennials-pot-bedding-plants/osmocote-controlled-release-fertilizers/
Elemental levels in a typical product can be found he
https://icl-sf.com/uk-en/products/ornamental_horticulture/8746-osmocote-pro-high-k/

--

Jeff