When annual flowers are perennially troubled, switch species
I don't know if you remember, but last year I asked
about healthy impatiens wilting and dying in
mid-summer.
(We do remember, Wendy. You wrote, "I love impatiens. and
most of the plants thrive. However, every year, a few of them seem
to shrivel and die. The leaves get smaller and the stems seem to
shrivel." We told you about Alternaria,
Botrytis and other fungi that can invade damaged stems
and crowns to become chronic infections, and which may already be
present in some plants at purchase.)
You did some research and found some information about a
blight that is in the plants before we get them. And I thought that
was it! So, this summer, all seemed to be going well until July
when the odd plant here and there started in with the dying. And
one plant spread to the next plant so I started pulling the dying
and replanting. Those replacement plants did well here into
September.
Two things I've noticed:
- Impatiens in front of the house (west facing and
primarily shaded by a tree) have had no sign of this blight
and are doing well.
- The bed with the blight is east facing and the
impatiens that die seem to be in more sun at the end of the bed
rather than in the more shaded end of the bed. BUT - not all the
plants in the sunnier end die.
So, do you think it's in the soil? Or is it the sun? If
it's in the soil, should I remove some of the soil and replace with
new? Can I treat the soil with something? I did spray with some
lime sulphur in the early spring thinking that would kill whatever
blight might be lingering from last year.
Thanks for any thoughts
- Wendy -
We're glad you wrote again, Wendy. "What happens next" is vital
info. We apologize that our last exchange created the impression
that the problem was definitely that the plants started out
blighted. We commend you for putting yourself onto the right track
which is looking at the bigger picture. When it comes to recurring-
and whole-bed problems, that's where answers lie. In this case, we
see a whole species painting out a pattern that says, "We
Impatiens don't want to be here."
What we should have emphasized is that agents like fungi that
enter through wounded or cold-injured stems are not the real
killers. Stresses that makes a plant too weak to grow past or fight
off such agents are the problem. When a problem persists after you
eliminate all stress factors under your control -- by handling
plants gently, loosening subsoil along bed edges pressed by wayward
feet and tires in winter, not planting until the soil is warm, etc.
-- then it's time to give that plant species a break.
Impatiens love cool, partial shade. That individual plants
manage to keep going in your garden or anyone else's even after
their kin succumb to heat doesn't change that overall preference.
That replacements planted after July survive seem an additional
proof that midsummer heat was the last straw.
So, Wendy, look into other species this winter. Grow plants
there that are more heat-tolerant. One to consider is
Catharanthus (called annual periwinkle).
Sometimes just one step back, and one brief period of early
winter rest and mid-winter wonder time, lets the patterns we see in
the garden speak to us. - Janet -