Iris's are a vast and varied group remarkable
for the exotic extravagance of their flowers and also the range of
conditions in which various members of the group will grow. There
are iris's that will grow in standing water and others that will thrive
in dry shade. There are iris's of every available color and many bi, tri
and multi-colors that fade from one shade to another.
Botanically the Iris genus is divided
into a number of subgroups with similar characteristics, but most have
some similar traits.
They grow from an underground storage
organ, sometimes a bulb, but more often a rhizome - a swollen stem that
grows at ground level half in and half out of the soil. An iris will
usually flower in spring or summer though some of the bearded forms are
"remontant" that is - they will flower again the same year if
conditions are right for them.
Iris's may be propagated by seed or by
lifting and splitting rhizomes where they most readily separate. There
are often found small offsets that can also be removed and grown on,
initially in a plant pot and compost before being planted out in the
garden.
Iris's are clump forming, on average
18-24 inches in height and spread, but can be considerably more in the
case of beardless varieties or only 4-6 inches tall for some of the
early spring flowering bulbs.