In message , Janet Baraclough
writes
I've been growing clematis for 47 years, I can assure you that if you
plant a set of leaf nodes below the surface and you have a wet spell
within a week or so, then you can expect to get rot and lose the plant -
not necessarily but there's a good possibly..

I've always planted clematis deep for the same reasons Rachel has
given, and find they do very well; even though they invariably have a
wet spell soon after planting. I live in the extremely wet west of
Scotland; rainfall at least 70" pa and rising.

Experts are divided as to what causes Clematis wilt (which seems to be
the underlying motive for deep planting).

The reason for the deep planting recommendation is that it is believed
by some (many?) to be due to insufficient water in the flowering season
- usually accompanied by a fungal infection (opinion is divided as to
which precedes which), as well as "insurance" in getting new growth if
wilt destroys the plant.

Its my view (shared by others) that its better to address the cause than
to adopt the "insurance" view of deep planting that can often cause
rotting of the stem if a long wet spell follows planting.

Clematis wilt (I've never ever experienced it myself) can, in my view,
be avoided by well watering in the flowering season. And if wilt appears
can invariably be rectified by the application of Benomyl (Benlate).

Clematis wilt invariably occurs in (or immediately before) the flowering
season, and by that time the root system is sufficiently developed to
regenerate the plant by the next season - even if the Benomyl doesn't
restore the plant that season.

IMHO more clematis are lost in the first season through rotting of
buried portions of the newly planted stem following wet periods
(especially in heavy or badly drained soil), compared with those that
are lost by wilt (which rarely occurs at planting time). This is why I
disputed the advice given.
--
Tony Morgan