Dutch iris requirements

Rodger Whitlock totototo@mail.pacificcoast.net
Mon, 15 Sep 2003 06:17:38 PDT
On 11 Sep 03 at 13:27, James Waddick wrote:

>  Can anyone report long term success with them?

Quite a long time ago, I bought a cheap mixture of Dutch irises -- in 
a little box from Safeway (chain grocery store), iirc (if I recall 
correctly). These went into a narrow strip of soil between a raised 
bed and a concrete sidewalk,

There were three unnamed color forms in the box: white, yellow, and 
blue. Only the one color has survived in the long run, but it gives 
every evidence of being one of those plants that is a "survivor."

The other colors lasted 5-10 years before finally petering out. I'm 
being coy about which color is the survivor because I simply don't 
remember! They aren't very prominent on my radar screen, you might 
say, and I don't really pay them much attention except to say 
"they're back!" (I think it is the yellow that's survived, but am not 
absolutely certain.)

My impression is that Dutch irises (at least the surviving one) want 
lots of sun, a warm, dry summer soil, but not *too* warm and dry, and 
a heavy-ish soil with good fertility.

This points up another trap for newbies to bulb growing. It's
commonly said of tulips, for example, that they want "good drainage."
Many garden writers then make the illogical leap to saying that
tulips want a *sandy* soil. This is complete b.s. and is a snare and
a delusion.

Tulips don't mind a heavy soil, but they detest stagnant winter
moisture. My own garden has fairly heavy soil that gets standing
water in low spots during the wetter periods, once the ground is
saturated. But even under these dire conditions, a bed raised only 
15" above grade in one of the lower (hence wetter) spots produced 
good results with a number of species tulips. (Remember that I am in 
a winter-rainfall, summer-drought area of the PNW.)

Amaryllids also seem to enjoy my rather heavy soil. Crocuses do not
thrive unless sited with extreme care; they seem to be plants that 
enjoy a soil that is, unlike mine, downright sandy. I remember with
great pleasure the late-winter carpet of Crocus tommasinianus in
Doris Page's old garden, growing on nearly pure sand left by the
glacier 10,000 years ago.

Turning back to bulbous irises: I actually prefer the English irises 
to the Dutch. I have a white form "Mont Blanc" and a lovely unnamed 
violet-blue form, and they are persistent.

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

on beautiful Vancouver Island

More information about the pbs mailing list