Plant in an open sunny location in a well-drained soil where it is quite drought tolerant and needs only be irrigated occasionally to infrequently once established – over watered plants are floppy and weaker and dislikes overly wet conditions. The lavandins are cold hardy to below 15 degrees F and can be long lived if pruned hard after flowering in late summer – cut back deep into the leafy stems above the hard wood but do not prune in late fall or winter. The lavandin varieties of lavender are the most commonly used lavenders to extract lavender oil but, besides their commercial use, they are great in the garden and useful for fresh sachets, dried for potpourri and the edible flowers for salads or cooking. As with most lavender they are quite attractive to bees and butterflies, but not particularly to browsing animals – deer tend to leave alone but rabbits sometimes nibble at the leaves.

Lavandula x intermedia 'Riverina Thomas' is a cultivar of Lavandin, Lavandula x intermedia. Lavandin is considered to be a naturally occurring hybrid between English Lavender, Lavandula angustifolia, and Spike Lavender, Lavandula latifolia but this plant has an even more complex pedigree as it is a triploid hybrid that was created by crossing the popular dark flowering Lavandula x intermedia 'Grosso' with English Lavender, Lavandula angustifolia. It comes from the breeding program of Dr. Nigel Urwin of Charles Sturt University in Wagga Wagga, New South Wales, Australia. In 2003 through a selection program in Riverina, the agricultural region of south-western New South Wales where Charles Sturt University is sited, the world’s first commercially available polyploid lavenders were released with names such as 'Riverina Alan' 'Riverina Margaret', 'Riverina Eunice' 'Riverina James' and 'Riverina Thomas'. Dr. Urwin published a report about his work in 2009 in the Improvement of Lavender Varieties by Manipulation of Chromosome Number published by Australian Governments Rural Industries Research and Development Corporation, noting that "these plants should be higher yielding and produce equivalent or better quality oils than currently grown varieties.". In this report he lists the parentage of 'Riverina Thomas' (originally having the code name L. x intermedia 'CSU150') as having Lavandula x intermedia 'Grosso' as the seed parent and Lavandula angustifolia as the pollen parent. This article also notes that another triploid named 'Riverina Alan' was the result of crossing as Lavandula x intermedia 'Seal' with Lavandula angustifolia.

We started growing this variety in 2021 and also grow the other Lavandin cultivars Lavandula x intermedia 'Alba', Lavandula intermedia 'Grosso', Lavandula x intermedia 'Provence', Lavandula x intermedia Phenomenal [Niko'], Lavandula intermedia 'Super', and in the past grew a variegated variety called Lavandula intermedia Silver Edge. 

This information about Lavandula intermedia 'Riverina Thomas' displayed is based on research conducted in our horticultural library and from reliable online resources. We also will relate observations made about it as it grows in our nursery gardens and other gardens we have visited, as well how the crops have performed in containers in our nursery field. We will also incorporate comments that we receive from others and we welcome hearing from anyone with additional information, particularly if they can share any cultural information that would aid others in growing it.