Hot pipe callusing at Kirkley Hall
In 2004 Kirkley Hall Horticultural College successfully approached Plant Heritage for financial support in their quest to develop a Hot Pipe Callusing system to improve their success rate in the propagation of their beech collection at Kirkley Hall.
The notion of using a hot pipe system when bench grafting is a relatively new technique in the field of grafting (if you pardon the pun), that is it was first described in print back in the 1930’s. This is of course modern if one is to accept that the art of grafting dates back into antiquity.
The concept of the system is to allow callus or healing tissue around the graft union before the initiation of scion and/or root growth. The combination of this three way pull often leads to failure because of the stress it puts on the plant, but with using the hot pipe callusing system means that heat is only applied to the grafted area of the plant whilst the scion and rootstock remain cool. This prevents drying out and it delays growth.
The system employed at Kirkley Hall involves the use of a drainpipe and ordinary soil-warming cable, the latter being governed by a thermostat. A steady temperature of 24°c for 21 days is prescribed as suitable for Fagus.
Other species which can benefit from this technique include various fruit crops and ornamentals like maple (Acer) and hazel (Corylus).