If you raise a bed, consider the run-off
To make a good garden, I built a raised bed...
...where the existing soil was very hard packed and poorly
drained. By the time I was done planting I was so excited about how
many neat things I could grow there, that I kind of forgot why I'd
made the raised bed to begin with. When I looked at the finished
product I thought, "Now all it needs is a nice border."
I knew yew makes a great low hedge, so that's what I planted to
outline my masterpiece.
Within a few weeks I saw my mistake. The yews yellowed and
failed. They weren't on the bed above the wet but right in
a gutter, where the water would drain off the berm and pool on top
of the poorly drained original soil.
I know yews don't like wet so why did I plant them in a space
bound to be soggy?!
Right: Yew (Taxus species) are quick to tell of
poor drainage. See the yellowing here? It's a classic flag and Poor
drainage is the cause.
Like a canary in the coal mine they'll be the first ones to
keel over and die when the environment changes. Just as miners
can't see the gas that might kill them, we can't see that excess
water in the eighteen inch depth where most roots grow. So test for
it and plant to suit existing drainage. For more about drainage and
how to test for it, check What's Coming Up #15.