On Tue, 31 May 2011 08:18:43 +0000, Julian200
wrote:


I purchased and planted a Cornus florida in the autumn, it looked
healthy when I purchased it, but this spring it did not produce many
leaves and the few produced are starting to die back from the tips,
some of the small branches have died as well. Is this the disease
dogwood anthracnose? would the tree already have already been infected
when I purchased it?


On the one hand, florida is the most susceptible of the cornus
varieties. On the other, whilst I've only seen one case of cornus
anthracnose "in the flesh" it didn't look anything like your photos.
The die-back was black rather than medium brown and the "spots" were
far more distinct than the brown blotches the photos show on some
unaffected/less affected leaves. That said, I've never seen a
variegated florida variety before so variegated leaves may respond
differently for all I know.

IMO, the die back looks more like a case of too much wet on top of the
effects of a heavy winter on a newly planted specimen. Florida is not
that hardy and the last winter put paid to a lot of more hardy and
established plants. FWIW, I don't plant in autumn, preferring to
accept the watering overhead with spring planting - I work on the
basis that the plants have a spring/summer/autumn to prep themselves
for whatever winter chucks at them.

Florida needs a fertile, neutral to acid soil to grow reliably and
will falter badly if the soil is alkaline. Similarly it also hates wet
and really needs a sunny spot to grow well. The grass in the
background is saying to me that it might not be planted in the right
place.

So on the basis of the photos I don't think it's anthracnose, though a
first hand check will be more reliable. You could bag up a couple of
bits (seal well in a clear polythene bag) and take them back to where
you bought it or to a local nursery or garden centre for a diagnosis.

If you want to grow cornus, look for european varieties. They're
resistant to the disease.

Cheers
Jake