Kathleen
Sayce
Pacific
Coast Iris (PCI) can be so touchy to lift and transplant that
gardeners may wait years––letting a particularly choice plant
increase in size so that half or more of the clump can be left alone,
just in case it really doesn't want to be moved. Translate 'doesn't
want to be moved' as 'dies' and you have a pretty good idea of the
PCI response to conditions or changes in conditions that it doesn't like. PCI
aren't easy plants. They are a good challenge to a gardener's skill
set, in a rock gardening sort of a way. The payoff is that when they thrive,
the flower show is amazing, and unparalleled in the iris world.
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| Iris tenax x innominata seedlings in their third year. These plants flower weeks later than modern PCI hybrids, extending flowering from early June into early July. Photo by Kathleen Sayce |
I
have a pale yellow PCI seedling in my garden that I left to grow an
additional year, just in case it doesn't take well to being
divided and replanted. I'm waiting this spring to see how it
responded to being moved last fall. If it survives, no, if it
thrives, then I'll be sending plants out to several growers to see
how it does in other gardens. It has many marks of a new and
desirable hybrid, and the flowers are nicely complex, with a delicate turquoise flush, golden yellow signal and reddish veins, an open and upright flower, a sturdy base of leaves and strong
shoots. The current test is to see how it transplants; desirable PCI
seedlings often fail at this test.
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| This seedling PCI last year had lovely flowers with golden signals, reddish veins and a turquoise flush on the falls. This year, I dug it up, divided it, and moved it. Will it thrive? We'll know in a few months. Photo by Kathleen Sayce. |
Choosing
when to divide and transplant PCI can be funny to watch from outside
the garden. The gardener pulls soil and mulch away from the base of
the plant, looks closely, shakes her head, pats the materials back in
place, then moves over to check the next plant, then the next... then goes away for a few days
or a week. Or two weeks. Or a month. We are looking each time for
that clear sign of a growing PCI–-live white roots on the base of
the leafy shoots. Live roots grow twice a year, in spring and fall.
In cool moist climates, new roots can grow for several months, almost
year round, while in climates with prolonged dry summers, they might
grow for only a few weeks: 6-8 at most in fall and spring, with cold
weather slowing growth midwinter, and dryness slowing growth midsummer.
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| Fall is a good time to transplant PCI. These plants have sturdy shoots with white roots on the current year's fan. The new fans are visible as tiny sprouts above the roots, on the left side of both transplants. These transplants are from a vigorous yellow-flowered I. douglasiana selection. Photo by Kathleen Sayce |
Why this spring and fall root growth pattern? PCI are native to the
West Coast of North America, which has a Mediterranean-type climate.
This means that there is a brief to very prolonged dry season each
summer, depending on latitude, when PCI go summer dormant. When rains
return in the fall, they produce tiny new fans of leaves with tiny
buds of roots; and older roots just behind them, on the current
year's fan, start growing again. The new fans elongate in late winter
and spring, and shoots emerge to bloom in early spring to early
summer, depending on latitude and climate. In late spring to summer,
PCI set seed, and go dormant for the balance of the summer season.
They awaken in fall with the onset of cooler temperatures and rain,
producing new roots and tiny new fans.
Nurseries
know this, and depending on where each is located, aim to ship plants
when their roots are growing strongly. This is most often in the
fall. For gardeners accustomed to shopping for new flowers by seeing
flowering plants at a nursery, and taking them home, this delay can
be frustratingly long.
Patience
is everything in a garden. Growing PCI is a study in patience. You
see the plant. You find a nursery that sells that plant, and place an
order. You wait. That fall, or the next, it arrives, and you plant
it, and you wait. Perhaps it dies––these are PCI we are
discussing, after all. So you try again. When it flowers, you see
that it's the plant you sought. Or not. And you try again. But what a reward with success.
