Muscari (in containers) trial 2024

Objectives and purpose of the trial

This trial focuses on Muscari (grape hyacinth) cultivars as container plants. The last time Muscari were trialled at the RHS was in 2003, as part of the Hyacinthaceae trial. Since then, new selections have been introduced. The trial will compare, record and display the merits of new and established cultivars to see how they perform. Those that perform best will be awarded the RHS Award of Garden Merit (AGM).
Plant portrait of Muscari ‘Night Eyes’
Muscari in containers trial at RHS Wisley

Plants and location

What was planted?

Fifty different Muscari selections are being grown in pots at RHS Garden Wisley, representing many of the Muscari that are currently available. This includes some species, some well-known selections, as well as some new introductions. Muscari comosum ‘Plumosum’ has been known since 1612. ‘Nature’s Beauty’, ‘Emmy’ and ‘Flower Desire’ were all registered in 2023. Many of the bulbs will form part of the Alpine collection after the trial, or be planted out into the wider garden.

Where is it planted?

The bulbs were planted in terracotta containers (37cm diameter), 10cm deep in the Trials Garden at RHS Wisley. Here are some considerations for planting out Muscari:

  • Muscari are hardy and can be planted in the ground, or containers, in a sunny or partially shaded, free-draining site
  • They are perennials and will come back year after year
  • Muscari are small spring-flowering bulbs, with vibrant blue, light blue, pink, white or even yellow flowers in some species

  • Muscari combine well with other spring flowers. Try planting under taller plants like daffodils or clump-forming perennials such as peonies with colourful spring foliage
  • Muscari are early sources of pollen and nectar for pollinators
  • Some grape hyacinths spread more vigorously than others – we’re testing this in the trial by looking for how many offsets, or bulbils, each selection produces

Top Muscari tip

Some Muscari selections naturalise well in garden borders and lawns, forming brilliant colourful carpets. If you want to reduce their spread, cut back flowers before seeds are fully developed.

Judges and criteria

Judges of the trial

The trial judges include 10 experts, involving collection holders, horticulturalists, garden writers, members of the RHS Bulb Committee and RHS Alpine and Rock Garden Committee. They will visit the trial every other week throughout March and April, with a wrap-up meeting taking place in May.

The trial results will be confirmed by the Bulb Committee, and the Trials Team hope to share the results in time for buying Muscari bulbs in the autumn.

The 2024 Muscari forum includes: Alex Hankey (Alpine Team Leader, RHS Wisley), Andy Byfield (Botanist and Conservationist), Camilla Bassett-Smith (Television Presenter and Writer), Coralie Thomas (Assistant Head Gardener at Great Dixter House and Gardens), John Amand (Owner, Jacques Amand International), Kit Strange (Bulb specialist, RHS Alpine and Rock Garden Committee), Matt Bishop (Bulb specialist, RHS Bulb Committee), Ray Drew (Alpine Garden Society and RHS Alpine and Rock Garden Committee), Richard Hobbs (Botanist, Muscari National Collection Holder) and Teresa Clements (RHS Bulb Committee Chair).

Judging criteria

The following factors are all taken into consideration as part of the judging of the trial:

  • Flower form, uniformity and impact
  • Length of flowering period

  • Weather resistance
  • Leaf quality and prominence

Muscari in full bloom during trial at RHS Wisley
Plant portrait of Muscari latifolium ‘Grape Ice’

Cultivation

Planting process

The Muscari bulbs arrived in October 2023, for planting out in the first week of November. The aim was to plant 100 bulbs of each entry in containers with a potting mix of peat-free compost and grit and a top dressing of grit was also applied to each container. The bulbs were arranged concentrically from the centre outwards and with the bulbs touching each other.

Size differences between each entry meant that for some entries 100 bulbs fitted easily within the container with a gap around the edge. Some bulbs just fitted into the container, and for others, 100 bulbs couldn’t fit. The number of bulbs planted for each trial entry has been recorded.

The pots were left outside over winter to expose the bulbs to the winter weather. Where very low temperatures were forecast, the pots were covered with fleece, as the Trials Garden site is very open and prone to extremes. At the end of the spring of 2024, bulbs were lifted from the containers to check how many new offset bulbs each entry produced and this was compared between entries.

How we’re managing plant health

Muscari are generally not affected by any diseases or pests. Smut may occasionally be a problem. Botrytis, grey mould, has been identified on some of the trial entries showing leaf yellowing and dieback and a fuzzy grey mould. The entries have been taken out of the trial display and where any further infection is noticed, damaged material will be removed to reduce the spread of the fungus.

Although they are not usually a favourite snack for deers or rodents, the pots were initially surrounded by an electric fence to protect from any potential animal damage.

I’m looking forward to discovering how well these plants grow in pots as this is a different way for people to grow them.

Gemma Burr, Trials Horticulturalist
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Plant portrait of Muscari latifolium
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Planting out Muscari bulbs in November 2023
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Muscari trial on display on an overcast day March 2024
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Plant portrait of Muscari latifolium
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Planting out Muscari bulbs in November 2023
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Muscari trial on display on an overcast day March 2024
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How to grow <i>Muscari</i>
How to grow Muscari

Explore all the information you need to know to grow and care for Muscari in your garden.

How to grow Muscari

Suppliers to the trial

List of plants in the trial

View all the cultivars of Muscari on trial at RHS Wisley
  • Muscari ‘Alaska’
  • Muscari ‘Aqua Magic’
  • Muscari armeniacum
  • Muscari armeniacum ‘Alida’
  • Muscari armeniacum ‘Atlantic’
  • Muscari armeniacum ‘Big Smile’
  • Muscari armeniacum ‘Blue Spike’ (d)
  • Muscari armeniacum ‘Cupido’
  • Muscari armeniacum ‘Dark Eyes’
  • Muscari armeniacum ‘Fantasy Creation’ (d)
  • Muscari armeniacum ‘Manon’
  • Muscari armeniacum ‘Night Eyes’
  • Muscari armeniacum ‘Peppermint’
  • Muscari armeniacum ‘Siberian Tiger’
  • Muscari armeniacum ‘Touch of Snow’
  • Muscari armeniacum ‘Valerie Finnis’
  • Muscari armeniacum ‘Snowqueen’ (syn. of ‘Venus’)
  • Muscari aucheri ‘Blue Magic’
  • Muscari aucheri ‘Ocean Magic’
  • Muscari aucheri ‘White Magic’
  • Muscari azureum
  • Muscari azureum ‘Bling Bling’
  • Muscari ‘Baby's Breath’ (syn. of ‘Jenny Robinson’)
  • Muscari botryoides ‘Album’
  • Muscari ‘Carola’
  • Muscari ‘Casablanca’
  • Muscari comosum
  • Muscari comosum ‘Plumosum’
  • Muscari ‘Cool Blues’
  • Muscari ‘Emmy’
  • Muscari ‘Esther’
  • Muscari ‘Flower Desire’
  • Muscari ‘Flower Power’
  • Muscari ‘Ivor’s Pink’
  • Muscari ‘Joyce Spirit’
  • Muscari ‘Julia’
  • Muscari latifolium
  • Muscari latifolium ‘Grape Ice’
  • Muscari ‘Lindsay’
  • Muscari ‘Marleen’
  • Muscari ‘Mount Hood’
  • Muscari ‘Mountain Lady’
  • Muscari 'Nature’s Beauty’ (d)
  • Muscari neglectum
  • Muscari ‘Pink Sunrise’
  • Muscari ‘Soulmate’
  • Muscari ‘Superstar’
  • Muscari ‘Venus’
  • Muscari ‘White Pearl’
  • Muscari ‘White Spear’
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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].

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