I am having difficulty propagating Vitis coignetiae. The cuttings are
not taking. Any advice?
Here is what I found in the Plants for a Future Database:
Seed – best sown in a cold frame as soon as it is ripe. Six weeks cold
stratification improves the germination rate, and so stored seed is best
sown in a cold frame as soon as it is obtained. Germination should take
place in the first spring, but sometimes takes another 12 months. Prick
out the seedlings into individual pots when they are large enough to
handle and grow them on in a cold frame for their first winter. Plant out
in early summer.
Cuttings of mature wood of the current seasons growth, December/January
in a frame. These cuttings can be of wood 15 – 30cm long or they can be
of short sections of the stem about 5cm long with just one bud at the top
of the section. In this case a thin, narrow strip of the bark about 3cm
long is removed from the bottom half of the side of the stem. This will
encourage callusing and the formation of roots. Due to the size of these
cuttings they need to be kept in a more protected environment than the
longer cuttings. Cuttings are difficult from this species.
Layering: This is the best method for this species.
See the Royal Horticultural Society for general layering information.