Writing about his work in the Nursery, James T, one of the current interns, explains how he has approached propagating one of Israel’s rare and endangered plants.
Rheum Palaestinum is on Israel’s ‘Red List’ of Rare and Endangered Plants. It has ornamental potential but doesn’t seem to like it out in the borders of the Garden. Known as the desert rhubarb it is found in 32 sites around the Southern Negev, in the Southern Jordan Mountains and the northern areas of Saudi Arabia. Its preferred habitat is rocky ground, rocks and cliffs and desert rocks, usually above 850 metres and is often found growing with Artemisia sieberi, a companion plant.
This herbaceous perennial has a ground-hugging form compared with relatives grown in Europe with an interesting flower spike which adds to the ornamental potential in the right environment. The issue with using this plant within the Gardens here in Jerusalem is that it struggles in the winters of the city, but also the long tap root it sends out once germinated means it doesn’t like being transplanted. To combat this it is often put into deep pots to allow for the root system to develop correctly.
Taking this into account I have sown the seeds of this plant in two different ways. One using the standard shallow seed trays used in propagating most of the material in the nursery, which will be transplanted into a deep pot or bucket quickly after germination. The other seeds have been sown directly into deep plug trays; ¾ of the plugs filled with a standard mix with osmocote used in the nursery, ¼ is a propagation mix where the seed is placed. It seems to have worked so far – with some good germinations, hopefully meaning when the plant is transplanted into the garden or in a bucket it will have a better developed and less disturbed root system.
I look forward to watching this plant develop in the next couple of months, hopefully my little experiment works. If not, I’ve got the standard method (germinating today) as back up.
Further and more in depth information can be found at http://redlist.parks.org.il/taxa/Rheum%20palaestinum/