In this propagation activity, I took semi-hard wood cuttings from Spanish lavender bushes growing in the production area at TAFE. Summer to autumn is an ideal time to take semi-hard wood cuttings.
Propagation material was collected from the field and taken back to the shed to be washed in a diluted 1% ammonia solution to reduce the chance of disease (Damping off is common fungal disease of seedlings if good hygiene practises when sowing have not been observed). Lavender did not need to be transported in wet newspaper.
After filling and lightly firming a punnet with the propagation mix, I selected side shoot cuttings of about 10cm in length, being careful to cut horizontally at the base of the cutting below the nodal growth. Nodes are points of high growth activity and contain tissue that can readily differentiate into root growth for example depending on conditions.
Each cutting was dabbed into a petri dish containing a gel rooting hormone. Once all cuttings had been treated in this way, they could be placed sequentially in the growing media starting from the back of the punnet and working in rows to the front. A dibbler was used to make a small space for the cutting to fit in such a way that it would not easily fall after being watered, but being mindful to not have leaves touching the growing media that would otherwise encourage fungal growth.
The punnet was watered and then place in the misting house on a layer of sand. The misting system keeps cuttings cool and limits excess transpiration which is a major reason for propagation failure. Low punnets do have a higher water table but the sand layer they are placed on assists in drawing down excess moisture in the growing media by capillary action.
Hygiene practises observed : washing down table tops and cleaning secateurs with 1% methylated spirits, sterilising punnets, using pasteurised sand in propagation mix, using healthy, strong disease free material, washing cuttings in 1% bleach solution.
