From: "D. Christopher Rogers" <branchiopod at gmail.com>
on 2012.01.20 at 15:43:43
Hey, Peter!
=A0
When are you going to publish a new, updated and expanded edition of your Arum book?
=A0
Grins,
Christopher
On Thu, Jan 19, 2012 at 11:40 PM, Peter Boyce <phymatarum@googlemail.com> wrote:
Hi Don,
I grew a lot of Arum in pots in the past. You need to use deep straight-sided pots at least 12 inches, preferably 15 inches deep; the
problem is that pots this deep tend to be very wide too, so you may have to shop around.
Growing media for the Mediterranean species (such as those that you list) needs to have a good proportion of mineral soil and also should to be on the
alkaline side of neutral (8.5 or thereabouts). I used to mix a proprietary peat-based soilless-potting medium with the same volume of good quality sieved topsoil. To every 10 gallons of this mix I would add a heaped 6 inch
pot of 1/2 inch limestone chippings.
Tubers need to be planted ca half way down the pot. I used to re-pot annually in late N Hemisphere summer (late August); by this time the tubers will be becoming active but there won't be much root growth. Plant and then
water well and then don't water again until the shoots appear above soil. Arum are greedy plants and well-repay heavy fertilizing by producing larger tubers. I used to use a fertilizer branded for use on tomatoes. When
actively growing I would fertilize on every watering and the manufacturers rate.
Under glass Arum need a buoyant atmosphere and high light. Ventilate well on all but the very coldest days. The pots should also be given a fair bit of
room between - too close together and the plants can become very etiolated and become prone to leaf fungus such as botrytis.
Arum flower towards the late middle of their growing cycle. Some gardening books advocate easing back on water and ceasing fertilizer when the
inflorescences appear. This is wrong. The plants still have a few weeks growing ability during flowering and it is at this time that nutrients from the leaves are absorbed by the tuber; curtailing the growing period can mean
smaller tubers. I recommend that you keep the plants actively growing as long as possible to ensure a decent sized (or better still, more) tubers for the next year.
Once it is clear that the plants really are dying back (most leaves yellow)
stop fertilizing and reduce watering to just enough to stop the pot becoming completely dry. While the plants are dormant it is better to leave the tubers in the pot and not take them out. I experimented quite a lot of
tubers of which I had an excess and can say that tubers removed from the soil and stored were always weaker than undisturbed tubers. It is also important that the resting pots do NOT ecome excessively dry. Despite the
desiccated appearance of the Mediterranean countryside during summer digging down a few inches always reveals damp soil. Arum (indeed all Med. aroids) are always deep-buried in nature and certainly never become totally dry. It
is also worth keeping the resting pots someplace not too hot and certainly not exposed to sun - again the soil in the wild is always cool at the level the tubers occur, no matter how parched the countryside.
Hope this helps some
Pete
--
D. Christopher Rogers ((,///////////=3D=3D=3D=3D=3D=3D=3D< 785.864.1714
Crustacean Taxonomist and Ecologist Kansas Biological Survey Kansas University, Higuchi Hall 2101 Constant Avenue, Lawrence, KS 66047-3759 USA
=A0
Vice President, Southwest Association of Freshwater Invertebrate Taxonomists SAFIT.ORG
--bcaec51a759eaf181604b6f78b69--
--===============8595727486591074435==
|