Vetiver Plants in Winter Trials

VETIVER: UK WINTER TRIALS

Vetiver: UK Winter Trials

Vetiver a tropical grass, has been grown on a small scale in southern England for more than 5 years. As the first company to import, grow and sell Vetiver in the UK, we are conducting a series of trials, to better understand how well Vetiver will grow in the UK and how we can improve its growth and survival.

 

UK Winter Trials

Vetiver Plants in Winter Trials

Recent research has shown that Vetiver will survive to -10oC if the ground is not frozen for an extended period. Vetiver will survive frosts and snow. Experience has shown, that in the UK a significant percentage of Vetiver plants will die back in the winter but will recover and grow back the next Spring. Vetiver Grass UK has started a small-scale winter trial to investigate what are the best methods to improve the survival rate of Vetiver.

There are two trials running at the same time. The larger plants were planted in May 2022 and are well established. A selection of plants were weighed and measured prior to planting. These plants were also measured and weighed in September and showed a significant increase in biomass over the summer. We can therefore make an estimate of how well the Vetiver survives under the various winter treatments.

The smaller plants were planted late in August and are included as anecdotal evidence of the best protection for Vetiver over the winter, as they have had insufficient time to establish themselves over the summer.

 

Thermal Fleece

The first treatment is a thermal fleece, which offers increased thermal protection to the normal horticultural fleece used in gardens. The fleece was attached to hoops and secured to the ground. No further treatment will be used over the winter.

 

Netting

Horticultural netting is used in the second treatment, simply attached to hoops, and secured to the ground. No further treatment will be used over the winter

 

Poly Tunnel Plastic

The third treatment is the use of plastic, on both the large and small plants. A simple cloche was made using rebar in the ground and plastic water pipes, with Polytunnel plastic attached and secured. There are no plans to water the plants, as the Vetiver roots should be able to access available water in the soil.

 

Mulch

Woodchip Mulch on vetiver Plants

The fourth treatment is the use of a woodchip mulch. The mulch was added to a depth of 10 – 15 cm across the whole bed. The plants have not been trimmed back and will receive no further treatment over the winter.

 

Control – Trimmed and untrimmed

The final option are plants that have received no treatment and will function as the control. Several the plants have been trimmed to see if that will improve survival rates. The control plants that survive the best , will be used as the basis of a breeding programme to produce Vetiver plants suitable for the UK

 

Future Trials

Vetiver Grass UK, is already conducting extensive trials into the efficacy of using  Vetiver for Phytoremediation in the UK, in collaboration with  the University of Reading. There are plans to also investigate the impact of soil pH, watering regimes and shade on the growth of Vetiver in the UK.