Potting Mix

Submitted by stuartmurray@x… on Wed, 10/03/2012 - 09:29

Just finished checking 51 plants in pots which have travelled 900 kilometres and were effectively under cover for 4 days from Thursday 27th to Sunday 30th. They all appear ok and about a dozen had also endured being inside for two days at a local show the previous weekend. Last year I had similar good results after taking 60 plus pots north to the annual Nelson AGS show. That also involved a round trip of 900 kilometres. In previous years I had always suffered serious losses after taking plants on such long journeys and put the cause down mainly to the length of time the plants had been confined inside low light buildings.

Last weekends’ excursion was to support a three day show put on by the Otago Alpine Garden Group in conjunction with the Dunedin Horticultural Society and an International Daffodil Show. I put the vastly improved ability of my plants to endure such travel stress down to one change made after the Christchurch 2010 September earthquake. Below a picture of some of the damage.

At this time, a few days before the 2010 Otago show, I faced a major rethink on how to manage the collection. The simplest way to seemed to be to convert from recycling old potting mix to universally introducing a new mix. For some time I had been contemplating changing the “sharp gravel,” added some years before to the composted bark, for a “smooth river washed gravel”. It would not have been an easy task to make the change and had just carried on recycling the old mix, adding quantities of bark to replace the fine particles of decomposed bark removed during the recycling process. To clarify this I should add that no new potting mix had been bought during the previous eight years.

With a sand supplier a few hundred metres down the road the change was made to a rounded river gravel 2-4mm grade. The new potting mix using this gravel has since been used for all my larger and more mature plants which of course are the ones taken to various shows. After all the gravel seems to be only there for ballast, without it everything would soon be on its side with the very strong winds we experience here in North Canterbury.

Apart from me being told my hands are a lot smoother there has no noticeable change except for the improved condition of the plants after travelling.. The obvious conclusion is that with sharp gravel in the potting mix root damage was occurring on every trip, with the rounded gravel ----- problem solved.

It is not just earthquakes and high winds that make life interesting here, four months ago the plants above were under snow.


Submitted by Howey on Thu, 10/04/2012 - 05:32

hello Senecio:  Welcome to the Forum - that makes two Kiwis among us.  Was interesting reading about your experience with potting soil.  I too have been using used soil and, after buying a bad batch of new potting soil from a well known firm and having no germination, am wondering where to put my trust.  A nice thing that happens to me when using the old soil is that often the odd missed treasure will germinate along with the new seeds and, of course, a few weeds which I am pretty good now at identifying and eliminating.  Sounds like sharp sand is a very important part of the mix for alpines too.
It's wonderful how you folks in and surrounding Christchurch have managed to carry on and keep planting things regardless of all the problems you have had.  A friend of mine is on sabbatical in Christchurch at the moment and reports there is a lot of building going on there now.  Bravo!  Fran

Frances Howey
London, Ontario, Canada
Zone 5b

Submitted by RickR on Thu, 10/04/2012 - 09:31

Wonderful looking plant collection, Senecio!

I was reading through your anecdote, thinking to myself that even a week without light doesn't kill plants, but as you got into the crux of the matter, it certainly could make sense.  I remember reading more than once how sharp grit can damage fritillaria bulbs, I suppose the idea could be extended to roots in such a transportation situation, especially if you have bumpy roads and/or a stiff suspension vehicle.  No experience here.  I had not thought this concept could be that critical, having first hand knowledge of how houseplants in transport to big box stores get abused.  Certainly alpines are different, though.

Submitted by stuartmurray@x… on Thu, 10/04/2012 - 11:56

[quote author=Howey link=topic=1170.msg20012#msg20012 date=1349350376]
hello Senecio:  Welcome to the Forum - that makes two Kiwis among us.  

Hello Frances

Actually there are three of us . Try this link [quote author=Toole link=topic=374.msg17984#msg17984 date=1338716143]. I’m the grey beard, hence Senecio. Jandals and Toole recently spent a couple of nights here with Pete (not on the forum) who runs the only true alpine plant nursery in New Zealand, Hokonui Alpines in Gore.
Incidentally the Nelson Alpine Garden Society Winter Study Weekend was the 16th consecutive year at St. Arnaud. I’m pleased to say it was the concept of the then ARGS Winter Study Weekends which inspired the first, that and a good bottle of Port shared with the Nelson President and her husband.

Submitted by stuartmurray@x… on Thu, 10/04/2012 - 12:25

Hello Rick, thanks for your comments. I have really been tempting fate for the last two years regarding transport and vehicle springs. It makes the difference the potting mix without sharp grit has made to the plants ability to survive post-quake roads outstanding enough for me to want to spread the word. Below pics taken last year for the 2011 Nelson Show. I'm heading north again on the 12th for this years Nelson Show, confident enough of the plants surviving to be entering about 70 plants.

Submitted by Hoy on Thu, 10/04/2012 - 14:47

Now I know why I don't bring my plants on holidays - I don't have the right soil mix ;)

Submitted by Hoy on Fri, 10/05/2012 - 05:28

Sorry - just teasing :-\ You have a beautiful collection of plants! Here in Norway we don't have any shows like you have.