Propagating Asiatic Primula by Leaf Cuttings
by Derek Lockey, UK
In Primulas: The Complete Guide by the late Mary Robinson, it states, "On close examination of the upper surface of a mature leaf an incipient bud may be seen." I personally emphasize MAY because not all the leaves of all species posses this bud. I now use a magnifier to examine any Petiolarid leaf which I remove just in case there is a bud.
Having recently (October) started clearing the plants of large leaves in order to allow buds to expand and be easily seen, I realized that it may be possible to 'have a go' at rooting leaves, having achieved success with this method in the spring when I used my small heated propagator.
My Primula aureata are all plants off my original (which came from Ron McBeath). Sadly, 'mother' passed away which was my main reason for trying the leaf-bud method in the first case.
At present, I have five mature P. aureata plants with multiple crowns all grown from leaf cuttings. The earliest was rooted on the 21st of January 2000, in a Jiffy 7 (small compressed peat block which expands when wetted), which was in a small seed tray type propagator in the bottom on a piece of capillary matting at a temperature of 50 degrees F, and shaded from the sun. Always break the leaves away from the plant, as this diminishes the risk of viral infection. Do not use a knife as this will damage the plant.
Once the cuttings showed roots through the Jiffy 7's they were potted on into my normal mix: 1 part J12, 1 part leaf mould, 1 part grit, 1 ounce blood, fish and bone meal. My measure is a 3 litre pot, in this case.
In mid May these were placed outside until mid September when they were housed in my alpine house where the door is never closed and I have four louver windows.
Writing this ten days after taking 18 leaf cuttings I can see one P. aureata, one P. bracteosa and one P. scapeosa growing in stature. It does not look as if 'Netta Dennis' is going to provide any plants. I took five leaves, one has already rotted but I still have hope for the rest!
I hope this epistle will encourage someone else to 'have a go'. After all, they are just leaves which would probably rot in the compost bin, so why not let them take their chance in your propagator, and you may finish up with a show winner. Plants do like to grow and it is only we mortals who go about killing them. I will keep you posted on my success rates.
Best Wishes to all,
ADDENDUM: 13 November 2000
The leaf cuttings which were taken in early October (P. bracteosa, scapeosa and aureate) have been successful but not growing as strongly as they do in the spring. 'Netta Dennis' has not rooted at all so we will try again in the spring. In conclusion, it looks to me as if plants root better as they are coming into bud as the leaves appear to be in a state of active growth.