Good advice Peter (UK) On 15 November 2014 22:07, Jim McKenney <jamesamckenney@verizon.net> wrote: > I tried my first arilate irises over fifty years ago; they were the > regeliocyclus hybrid 'Chione' and Iris susiana. Both bloomed, but neither > lasted more that a year or two more. I still have old Kodachrome > transparencies of both (or maybe later acquisitions of both). Subsequent > trials of Iris susiana in pure grit filched from the local railroad tracks > (I was still in the thralls of the "good drainage" mentality) resulted in > plants which, although they persisted longer, gradually starved to death. > > Years later I tried again with a nice assortment When these were received, > I noticed something about them which at first puzzled me: it was obvious > that they had been grown in clay, red clay. > > When inexpensive and readily available stocks of 'Dardanus' became > available in the recent past, I decided to give these plant another try. > Several other hybrids and species were obtained at the same time. They were > planted in a raised bed of the local red clay. Most grew vigorously and > bloomed. Still under the influence of the drainage myth, I assumed that the > raised bed (it was raised well over a foot high). Most of the plants, > especially the bigger ones which had bloomed, were already rotting when I > dug a few in June to check them. > > It was at about this time that I had some exchanges with John Lonsdale > about the culture of these plants. What I took away from that was the use > of polycarbonate sheets to cover the plants after they bloom. > > I joined the Arilate Iris Society in 2013, thanks in part to Dennis' > preiodic reminders to this list about that group. I obtained fifteen > hybrids and planted these out in a simple, ground level (i.e. not raised) > cold frame out in a field (my community garden plots) in late summer. All > grew and the following year some bloomed. Sometime in May I covered the > frame with a glass door (I'm getting too old for this and have since > acquired some polycarbonate sheets). All of these (and some other arilates > acquired elsewhere) sailed through the summer without a hitch. Many > retained their foliage, some became completely dormant. > > In this part of the country, arilate irises ripen during May; guess which > month of the year is typically our wettest month? They will never dry out > if you don't cover them. > > I got a nasty surprise in September when I removed the glass: no sooner > was the clean, vigorous looking foliage exposed to rain than it began to > get spotty and die back. > > But the plants are obviously vigorous and otherwise healthy, and I'm > already counting next spring's chickens. > > The frame, which might strike some of you as useless, does have a > function; it prevents water running across the surface of the ground from > entering the framed area. > > In the literature, especially the rock garden literature, there are > articles (some of which read like calculus puzzles and kept me tied in > knots) discussing drainage. To make a long story short, I think it's > largely bunk as far as most summer dormant plants are concerned. What the > plants in question need is not good drainage: as long as they are growing > actively , they will probably thrive in a pig sty (at least until the pigs > get them). But as the time for dormancy approaches, what they need, and > this seems to be non-negotionable, is dry soil. That soil can be dried up > muck, dried up stable bedding, the local clay dried from its formerly > waterlogged condition - the sort of soil doesn't seem to matter, as long as > it is dry. > > When these plants are put into very sandy, gritty media they do get rapid > water passage; that rapid water passage also takes water soluble nutrients > with whatever else drains out. It amounts to a starvation regimen. > > Put them in the richest goop you can get your hands on and watch them > thrive - just remember to start to dry them off as they are coming into > bloom so that by the time they are entering dormancy the medium around the > rhizomes is dry. > >