Garden Plant Conservation Association of Australia Inc.

Member Articles: Salvia's Adventitious Roots

By Meg Bentley

Registered Salvia Collection

 

 
Salvia macrophylla

Adventitious roots at the base

 Also known as prop roots, adventitious roots arise from lower nodes and provide support to a stem. 

Root development is promoted by *auxin which is naturally present in the cuttings [*auxin: a class of substances in minute amounts which regulate the growth of plants - especially the root formation]. 

Leaf cuttings taken from plants like African Violets and Begonias are known to develop roots on the stem ... but it was very interesting to take a leaf (stem and leaf) of Salvia and insert it into potting mix which then eventually developed roots - forming a new plant of Salvia. 

The ones I've tried so far are SaIvia chinensis and S. oxyphora.  One can imagine roots forming along a hairy stem or hairs at the base of a stem, but these two are rather glabrous and showed no visible hairs.  These roots, formed on a stem, are called 'adventitious roots' [Latin:  adventitious, coming from outside], broadly meaning any root that emerges from an unusual position - such as growing on a leaf or stem. 

Australia: A Lavandula cultivar...

The History of Lavandula angustifolia 'Egerton Blue'

 

 by Rosemary Holmes

The Yuulong Lavender Estate was established in 1980. In 1981 it was not possible to buy more than 100 lavender plants in Australia. Sue and Dick Thompson from Coora Cottage Herbs in Merricks in Victoria sought lavender seeds from Dutch seed merchants in Holland, obtaining four different varieties. They grew the seeds and brought the first 1000 plants up to Yuulong - these were the old Dutch Lavandula angustifolia 'Vera', Lavandula angustifolia 'Nana', Lavandula latifolia and  Lavandula x allardii,  then also named Mitcham Lavender. 

As our Lavandula angustifolia 'Vera' grew on over the next couple of years, in the controlled trial Section 1 on the property, the variations became obvious.  Some inflorescences were pale blue, some deep blue to purple, some peduncles were longer, some plants flowered up to two weeks later, and some plants were more robust than others. Now we all know that you should not grow lavenders from seed, because of the great variations that can occur.  Always use heel or tip cuttings or tissue culture. 

As we harvested the Lavandula angustifolia 'Vera' each year, we marked the best quality bushes and only propagated from these. Then these plants were grown on, marked again, another selection made and then grown on again.  It took 10 years of careful selection to produce a dark flowering, sturdy lavender that dried to a deep blue and had good quality oil.  All plants in the collection were tested for oil over a three year period.