Question Re: bulb potting compost
J.E. Shields (Sun, 26 Sep 2004 12:08:34 PDT)

Hi all,

Now I'll show you how much opinions vary by coming out and flat
contradicting Roger. Never ever use any garden soil in a bulb potting mix!

In fact, it all depends firstly on what genera and species you are trying
to grow. Then it depends on your climate. In addition it depends greatly
on whether you are a compulsive over-watering gardener or a limited or
careful waterer.

I grow and have grown over the years, wild Hippeastrum species native to
South America. They are mostly from arid areas, and even those native to
Brazil's Atlantic Rain Forest area need a dry period. Add garden soil, and
they will simply rot away for you in a humid climate. They do not tolerate
the fungi and bacteria supported by common dirt and by organic
residues. The same things apply to many South Africa bulbs.

So let me repeat: If you have a rare or valuable bulb, do NOT use any
garden soil in your potting mixes!

Jim Shields
in usually wet, hot, and humid central Indiana where we are in our 6th week
of relative drought.

At 05:30 PM 9/25/2004 -0700, you wrote:

On 25 Sep 04 at 11:31, Lee and Scott wrote:

Question:
Is there a page/source/website, on which one can find the "formula"
or "recipe" for planting bulbs in pots and the technique for
over-wintering the bulbs in the pots?

That's a very interesting question. I suspect that you would find
each potted-bulb fancier has his or her own recipe, and may even use
different recipes for different bulbs.

The cardinal rule is that your mix *must* (MUST!) use ingredients
that are readily available in your area. For example consider the
famous John Innes potting composts, as they are called. It's an
English formula and uses the infamous "Cornish silver sand", which I
believe is hard to come by even in the UK these days. There's
absolutely no point trying to slavishly follow that formula. At the
same time, if you think the John Innes mix is what you want, you can
utilize locally available ingredients to give a similar -- by
no means identical -- result.

In addition, the type of mix you use depends on factors like the
yearly patterns of rainfall and temperature, the kind of pots you
want to use, and the bulbs you want to grow.

Or, to put it another way, what I use in zone 8 on southern
Vancouver Island will include ingredients you will find impossible
to buy, and probably won't work as well for you anyway.

And Jane McGary, about 300 miles south of me, but inland instead of
on the coast, at a higher elevation, and in a region where volcanic
effluvia are dirt common, will use a different mix from mine.

Some suggestions: use a soil-based mix, not a soilless mix based on
peat. Be careful to test the pH and adjust it using agricultural lime
or ground limestone. (Dolomite is not as effective for adjusting soil
pH as it is much less soluble.)

As for overwintering potted bulbs, since you are in

Wiarton, Ontario.
Zone 5a/5b

I cannot offer any advice except this: don't let them freeze through!

--
Rodger Whitlock
Victoria, British Columbia, Canada
Maritime Zone 8, a cool Mediterranean climate

on beautiful Vancouver Island
_______________________________________________
pbs mailing list
pbs@lists.ibiblio.org
http://www.pacificbulbsociety.org/list.php

*************************************************
Jim Shields USDA Zone 5 Shields Gardens, Ltd.
P.O. Box 92 WWW: http://www.shieldsgardens.com/
Westfield, Indiana 46074, USA
Tel. ++1-317-867-3344 or toll-free 1-866-449-3344 in USA