Viola (overwintering) trial 2023–2024
Objectives and purpose of the trial
Plants and location
What was planted?
Where is it planted?
In the Trials Garden at RHS Wisley, Surrey, each of the 16 entries consisted of 16 young plants that were arranged in four rows of four plants with approximately 30cm between plants. Here are some considerations for planting out violas:
- The best time to grow violas is during autumn when soil is still warm, allowing roots to establish
- Violas perform best in free-draining soil
- Plants can grow and cope well with winter weather and bloom readily in spring
- Although largely unaffected by pest, diseases and weather, violas can be affected by slug and pest damage as young plants
- Violas flower over a long time, which can be extended by deadheading spent flowers
Judges and criteria
Judges of the trial
The 2023–2024 Viola forum includes: Mike Smith (Chair, Plant Nursery), Andy Bunker (Plant Retail), David Creese (RHS Tender Ornamental Expert Group), Adele Dyer (RHS Plant Trials), Chris Finlay (Plant Breeding), David Foreman (RHS Herbaceous Expert Group), Phil Johnson (Plant Breeding), Duncan Mclean (Plant Retail), Philip Oostenbrink (Head Gardener) and Cathy Rollinson (RHS Herbaceous Expert Group).
Judging criteria
The following factors are all taken into consideration as part of the judging of the trial:
- Habit
- Flowering performance
- Colour and appeal
- Winter hardiness
- Pests and disease resistance
Cultivation
Planting process
It was agreed that the first row of four plants would be deadheaded every few weeks to see if this had any effect on flowering performance. The outcome of this was that it gave little or no benefit when compared to the plants that were not deadheaded.
How we’re managing plant health
Supplier to the trial
List of plants in the trial
View all the violas on trial at RHS Wisley
Handy tools and information
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Gardening advice
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Hardiness ratings
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Get in touch
For more information on our RHS Plant Trials or to access older trial reports, please get in touch with our team via email at [email protected].
Get involved
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