Hostas
are a very long lived perennial. Many clumps can
continue undisturbed in the same location for decades
and decades. However, it is common for the center parts
of such clumps to begin to decline over time. Clump
decline is also known as center clump dieback, fairy
ring and centering out. What is happening is that the
oldest tissue in the clump is starting to give up the
ghost.
Think about how hostas grow. You plant a single division
and it adds new buds and divisions on the outer edge of
the crown. Over the years, this increases the diameter
and size of the clump. So, the oldest part of the clump
is in the center.
Usually, this situation can be overcome by rejuvenating
the plant. Some people just take a shovel or sharp
garden knife and cut out the dead area. This will cause
damage to the surrounding crown tissue and should
stimulate new buds in that area. In a season or two,
that part of the clump will fill in again.
Another approach is to dig up the clump, remove the dead
part and cut the rest into smaller divisions. Again,
this will stimulate new buds and new growth to keep the
plant going just fine for another few decades.
If the plant shows signs
of Southern blight which
has rotted the center of the plant, you will want to
move the live parts to a new, uninfected soil after
soaking them in a mild solution of bleach (10-20%)
before replanting.
