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  Growing arums in pots
From: Don Martinson <llmen at wi.rr.com> on 2012.01.19 at 18:23:26(22507)
I'd like to try growing some of the Arum species (A. dioscorides v. syriacum
and A.creticum), but will have to do it in pots as I'm virtually certain
they wouldn't be hardy in my climate. I have a cool greenhouse available in

Is there anyone else growing these (or similar) in pots that can give me
some helpful hints (media, growing cycle, etc.)?


Don Martinson

From: "E.Vincent Morano" <ironious2 at yahoo.com> on 2012.01.19 at 21:33:19(22508)
Im doing it. it works fine

From: Don Martinson
To: "aroid-l@gizmoworks.com"



From: Peter Boyce <phymatarum at googlemail.com> on 2012.01.19 at 21:40:44(22509)
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

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


From: michael kolaczewski <mjkolaffhbc at sbcglobal.net> on 2012.01.19 at 21:55:55(22510)

Greetings Don,

( and Happy New Year !!)

I usually grow non hardy aroids in containers

that are deeper, for a number of reasons.

A deeper pot helps move water through the media.

A well draining mix, while retaining moisture, should not

remain saturated. The addition of some drainage material,

for instance pot shards, aquarium gravel, pumice, etc,

will help to facilitate water moving out of the pot. If these

containers will be outside, I usually have them sitting

on a few bricks or utility tiles to ensure that water will not

wick back into the potting media.

Since you and I share similar Hardiness and weather zones,

Our summers here in the
Midwest USA, can be challenging

for growing some plants, and while they may like or

need warm weather, do not want to be soaked, as our rainy

weather can and does affect both in ground and container plantings

during the growing season.

I set out tender plants daily in spring, bringing them in at night.

Only after the danger of frost has past, do they stay outdoors

24 /7. I will incorporate a short term fertilizer, usually 90 days duration,

into the media. I do supplement this with liquid fertilizer at third

of recommended label strength, about once every 3 weeks, during

the outdoor growing season. I apply a layer of gravel or mulch to help

keep weed seeds out of the pots. I also watch for various ants, who seem to

like to move into pots, and later can move into the house, when you bring

the pots back

Once the corms have gone dormant, I check for any disease issues, clean up

any soft spots, and repot if needed.

I will attach a photo of the mix I use, which is composed of Pine Bark fines

( 3/8 of an inch ) Rice Hulls, A composted Peat Moss, some leaf mold,

and sometimes perlite. Depending on what type of plants are going to grown

in the mix, I may add an additional mineral, or even a wetting / moisture

retention product, if needed for cultural needs.

Take Care,




From: "Paul T." <ptyerman at ozemail.com.au> on 2012.01.19 at 22:29:33(22511)
At 01:23 PM 20/01/2012, you wrote:
>I'd like to try growing some of the Arum species (A. dioscorides v. syriac um
>and A.creticum), but will have to do it in pots as I'm virtually certain
>they wouldn't be hardy in my climate. I have a cool greenhouse available in
>Is there anyone else growing these (or similar) in pots that can give me
>some helpful hints (media, growing cycle, etc.)?


I grow all my Arums in pots, outside in the open
in my climate. The majority flower most
years. I am guessing that I am likely warmer than you though?


Paul T.

From: The Silent Seed <santoury at aol.com> on 2012.01.20 at 05:16:32(22512)
I grow everything in pots - just treat them as houseplants - just know their dormancy cycle (The plants will tell you) and withhold water during this time. I use regular dirt, and keep them moist, but not wet.



From: "D. Christopher Rogers" <branchiopod at gmail.com> on 2012.01.20 at 07:43:43(22513)
Hey, Peter!

When are you going to publish a new, updated and expanded edition of your Arum book?





From: DAVID LEEDY <djleedy at sbcglobal.net> on 2012.01.21 at 04:48:13(22515)

I really appreciate your posts to Aroidl, as well as your book on Arum. As I continue, I will try to adapt my cultural procedures to those you suggest.

I am now satisfied that growing arum in containers in Fort Worth, Texas, USA, is not a problem due to the cold winter weather. However, I am not sure if the long, hot summers will not prove to be the major obstacle I face. Although a bit unusual, last summer we experienced 59 days where the temperature was 100 degrees F. or above (37.78 C.). The night time temperature was 60 degrees F. or above ( 15.57 C.) and quite a few nights it was above 70 degrees F. (21.11 C.) during the summer.

Any suggestions on how to keep the "resting pots someplace not too hot" and how to
keep the resting pots [so that the planting mix] "do[es] NOT become excessively dry?

David Leedy



From: Peter Boyce <phymatarum at googlemail.com> on 2012.01.23 at 15:35:02(22518)
Hi Christopher,

Probably never. The taxonomy and nomenclature will be kept up to date with periodic papers – did you get ‘the ‘Decade of Change’ paper – but that aside the new monograph will be someone else’s challenge!

Very best as ever




From: Peter Boyce <phymatarum at googlemail.com> on 2012.01.23 at 23:32:15(22519)

The best option is to try to plunge the pots up to the rims in a sand bed someplace shady and to keep the sand just damp. If space allows keep a pots width distance between each pot, from from the pots to the edge of the sand (if the sand is retained by walls. Alternatively dig a trench deep enough to contain the pots to their own depth, line with plastic sheet, punch a lot of holes in the sheet to enable drainage, and then full with sand. The problem with the latter option is that in time roots of nearby plants will infiltrate.




From: "D. Christopher Rogers" <branchiopod at gmail.com> on 2012.01.24 at 07:54:00(22522)
Dear David,

When I lived in the Mediterranean climate of northern California, I had summer temperatures that reached 48 degrees C/ 120 degrees F. I used to just put the pots on the north side of the shade house, in the shade, no direct sun and no water. They did just fine. I had A. italicum, pupureospathum, dioscoridis, palestinum, sintenesii, hygrophilum, cyrenaicum, and pictum all do just fine under these conditions.

I grew them in large pots, similar to what Pete described, is a soil mix that was one part peat, one part pumice, two parts sand, and two parts well rotted dry compost.

The Arum pictum was moved out to sunny location in late August and started getting water when the inflorescences first started poking up. The others were moved out into the same area in November and started getting water (rain) at that time.





From: "D. Christopher Rogers" <branchiopod at gmail.com> on 2012.01.24 at 07:44:24(22523)
Aw, shucks!

I really was hoping. Ah, well. I just love that genus. I am watching to see how my collection of Arum survives now that I have moved to Kansas. I lost the purpureospathum. The Arum pictums are in pots, sitting in a cool window in my house, as they would never survive the cold here. The others seem to be okay, so far . . .

No, I did not see the "Decade of Change" paper . . . where was that published?

Happy days,




From: "Marek Argent" <abri1973 at wp.pl> on 2012.01.24 at 10:00:20(22524)

I have grown Arum concinnatum and A. hygrophilum in pots.

I use standard pot mix and the pots are 4-6" (10-15 cm) depending on the tuber (rhizome) size.

A. concinnatum bloomed three years in a row, from March to May,

I lost it when I planted it outdoors and the winter was extremally cold in my area (down to -23C -10F)

A. hygrophilum (a new tuber tat I got last summer) bloomed in December,

and a second inflorescence a few weeks after (now).

The only problem may be spider mites, they can appear on Arum leaves from nowhere,

even if all plants at home are healthy.

I sprayed the leaves only once using Agrecol Magus 200SC, and they



Best Regards,




From: Sheldon Hatheway <sfhatheway at yahoo.com> on 2012.01.25 at 10:54:27(22533)
I must be missing something here. I've grown Arum italicum in my back yard (and thanks to birds dropping seeds, in my front and side yards also) for at least 40 years and they are just one short step away from becoming invasive weeds! I haven't tried any of the other arums mentioned for fear that they would take over like the italicums. Here in our part of the Pacific Northwest the temps can occasionally get down to near zero F. and it rains throughout most of the winter. Fortunately we have a sandy loam in our part of town so water never stands for long, even in heavy rains (like the last few days). Maybe I should man up and try some of the other arums and see if they would do well outside all year long as well.




From: DAVID LEEDY <djleedy at sbcglobal.net> on 2012.01.27 at 10:36:38(22542)
Dear Peter,

The problem with writing a book is that you now become the expert on that subject, even when you want to go on to other things. I hope you bear with me (us).

Your 1993 book, "The Genus Arum," lists 25 species. I read in the publication of Arum megobrebi (2007?) that there are now 29 species. I assume that numbers 26-28 were described in the 2006 revision of your book.

Is there someplace, other than the 2006 revision, that I can find those descriptions? How many species are there now in 2011, what are they, and how can I find descriptions?

Also, if I read your book correctly (ref. page 133), arum detruncatum, as shown in Vol. 30 - 2007 issue of AROIDEANA should have been labeled as arum rupicola, var. rupicola. Was that an error in AROIDEANA?

Again, I apologize for my inability to read "scientific stuff," but aren't Bedalov and Kupfer suggesting that A. cylindraceum and A. sintensii are species in their 2006 article "Studies on the Genus Arum" in Vol. 29 of AROIDEANA? Also, in their species charts, they seem to have omitted both A. alpinum and A. lucanum. If they are of the A. alpinum = A. maculatum school, as described in your book, then I can understand why they may have omitted it. However, you have listed A. lucanum as being from Southern Italy, so one would think that it should have been included in their charts?

So, just how many species are there now? What are they? Where can descriptions be found? And is a referee or umpire needed for taxonomists?

Thank you.

David Leedy, Arum Fervidus Novus



From: Peter Boyce <phymatarum at googlemail.com> on 2012.01.31 at 23:30:02(22545)
Hi David,

Yes, there have been a few changes since 1993 and even since 2006.

sintensii was ‘raised’ to spevcies in the 2006 paper; cylindraceum (which I treated as a nom. dub. in 1993) has been shown to be the same as A. alpinum and, as it was published earlier, now must be used.

Arum lucanum is a syn. of A. cylindraceum (tackled in 2006)

Regarding descriptions, sorry, but for most of those not in the book you have to go back to the original publication place. Of course this raises new problems in that most are not described in English.

The full ‘official’ list for Arum is:

1. Arum alpinariae (K.Alpinar & R.R.Mill) P.C.Boyce

2. Arum amoenum (Engl.) Dubovik

3. Arum apulum (Carano) P.C.Boyce

4. Arum balansanum R.R.Mill.

5. Arum besserianum Schott

6. Arum byzantinum Blume

7. Arum concinnatum Schott

8. Arum creticum Boiss. & Heldr.

9. Arum cylindraceum Gasp.

10. Arum cyrenaicum Hruby

11. Arum dioscoridis Sm.

12. Arum elongatum Steven

13. Arum euxinum R.R.Mill

14. Arum gallowayi sp. nov. ined.

15. Arum gratum Schott

16. Arum hainesii Agnew & Hadac ex H. Riedl

17. Arum hygrophilum Boiss.

18. Arum idaeum Coust. & Gandoger

19. Arum italicum Miller

ssp. albispathum (Steven ex Ledeb.) Prime

ssp. canariensis (Webb. & Berth.) P.C.Boyce

20. Arum jacquemontii Blume

21. Arum korolkowii Regel

22. Arum longispathum Reich.

23. Arum maculatum L.

24. Arum maurum (Braun-Blanq. & Maire) stat. nov. ined.

25. Arum megobrebi Lobin, M.Neumann, Bogner & P.C.Boyce

26. Arum melanopus Schott

27. Arum nigrum Schott

28. Arum orientale Bieb.

29. Arum palaestinum Boiss.

Arum pictum L.f. = Gymnomesium pictum (L.f.) Schott

30. Arum purpureospathum P.C.Boyce

31. Arum rupicola Boiss.

32. Arum sintenisii (Engl.) P.C.Boyce

In addition to the above, I am aware of five further novel species (but of which I have seen only images) that are in cultivation in the USA, the Netherlands & Poland.

I am also now convinced that my treatment of the species A. rupicola and A. orientale were both too broad: at least A. conophalloides, Arum consobrinum Schott, and A. incomptum probably need to be resurrected.

Regarding ‘refereeing’ – no-one does this; it is all down to general acceptance.




From: DAVID LEEDY <djleedy at sbcglobal.net> on 2012.02.01 at 05:47:19(22546)
Subsequent to the below posting, I have found "A Decade of Change" by P.C. Boyce in the 2006 issue of AROIDEANA, Volume 29. Although I have not yet thoroughly read that article, it is obvious that just how many arum species exist is a complex issue, which varies as time continues. So, I believe that my question as to "how many species are there" is a little naive.


David Leedy, Arum Fervidus Novus



From: DAVID LEEDY <djleedy at sbcglobal.net> on 2012.02.04 at 12:21:11(22551)

Thank you so much. Your response is really appreciated by this novice enthusiast.

David Leedy



From: "D. Christopher Rogers" <branchiopod at gmail.com> on 2012.02.06 at 08:13:48(22553)
Thanks for the great review of the species in Arum.

One issue though, Peter: you said that there is no refereeing, just general acceptance. I have no real clue how things are done in the botanical realm, but in the zoological realm all species descriptions that are submitted to quality scientific white literature (as opposed to grey) type journals are in fact refereed. Typically, two to four referees give the manuscripts a solid review before they are accepted (or rejected) for publication. There are certain standards of taxonomy in zoology.

Happy days,




From: Peter Boyce <phymatarum at googlemail.com> on 2012.02.07 at 15:55:55(22561)
Hi Christopher,

Sorry, I thought you were referring to acceptance of names post-publication (for which in Fungi there IS a committee). In order to publish in botany there are the same set of “hurdles” as there are for zoology.

Very best Peter



From: DAVID LEEDY <djleedy at sbcglobal.net> on 2014.03.14 at 06:05:42(22989)
Hi Peter,

It is I, again.

In February of 2012, you emailed me a list of the 32 recognized species of Arum (see below). I see from the "uber list" that
there are now 40 recognized species of Arum. Could/would you list the additional 8 species or a list of all 40 and, if possible, advise me as to where I might obtain a copy of the publication on the internet.

Thank you very much.




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