Introducing two new plants from Knoll Gardens

Knoll Gardens is delighted to introduce Festuca Blue Haze and Panicum Sea Mist. These new plants are being introduced this Spring 2021 and are a result of our ongoing programme of selecting new grasses that will perform well in UK gardens.

Festuca Blue Haze is a selection from the native grass Festuca rubra and produces slowly increasing mats of bright powdery blue foliage that tend to be longer lived than other forms of blue Festuca. Best in a sunny open position with a soil that is not winter wet. Height; 20-40cm. .

Panicum Sea Mist is a selection from Panicum amarum and forms clumps of fairly upright, blue grey to sea green foliage that is topped with light coloured spikes of arching flowers in later summer. Best in sunny open positions with a soil that is not winter wet. Height; 1.2m – 1.5m.

Like any new plant that is intended to become a long term success in our gardens Panicum Sea Mist and Festuca Blue Haze have been some years in the making. Here at Knoll while we do not set out to breed new plants we do keep a sharp eye for variations or seedlings amongst the many thousands of plants that we grow each season. This is how most of our new selections such as Miscanthus Cindy, Pennisetum Dark Desire and Molinia Breeze have come about. It is a slow process but a fascinating one as initially there may be only a slight hint of a plants potential, a suggestion of what it might become, and patience is required while the plant develops its character. Far more plants are rejected or otherwise fail this process than ever make it through to being named and launched!

Festuca rubra, with its gradually creeping nature, is a major constituent of our mown turf and like most lawns will turn brown during dry periods without water. Interestingly if this grass is not cut on a regular basis it stays green in dry periods for much longer without any additional watering and it was from a patch of non mown Festuca rubra that we had in the garden that we first noticed some blue ish leaves appearing. As is our usual practice we selected a small piece and gradually over a period of years refined and re selected the plants with the most blue foliage. When we felt that the selection was reasonably stable as the next stage we planted a small number in the Gravel Garden (image below), to see how they behaved. After several years in poor soil with very little moisture Festuca Blue Haze has kept healthy and slowly made neat mats of soft blue leaves.


In comparison to other blue foliaged festuca such as the rather lovely Festuca Intense Blue or Festuca Elijah Blue the foliage colour is very similar with perhaps Blue Haze tending to be a little lower in height and less inclined to flower. Its main advantage, apart from being a selection of a native grass species, is perhaps its longevity; its ability to gradually form mats and so last in the garden for longer than the other blues. While quick growing and undoubtedly beautiful when young most blue festucas are selections of Festuca glauca, which is clump forming, and so under garden conditions need splitting and dividing every few years (or even annually in some soils), in order to keep them healthy. Otherwise they are rather short lived and need replacing. Festuca Blue Haze with its native background is better equipped to last longer in our gardens and with less attention. Like all festucas it will grow happily in a pot or in the garden in sunny positions with soil that is not too wet. As with any blue foliaged plant the colour is at its best during the sunny summer months.

Panicum Sea Mist (images above and below), is a selection from the species Panicum amarum which is a North American grass that is found in a range of coastal habitats and a variety of soil types though is very happy in light sandy soils. It is a very adaptable species that can be found with both a spreading and clump forming habit. Panicum Sea Mist was originally one of  a small batch of Panicum amarum seedlings that were raised on the nursery as part of a trial and were initially chosen for their attractive foliage and generally clump forming upright nature. The seedlings were subsequently planted out in the Dragon Garden for several years to assess their performance under garden conditions. From this small group the very best plant was selected for production on the nursery and given the name Panicum Sea Mist. Its habit is elegantly upright with a slightly arching tendency especially as the flowers appear and can produce some beautifully delicate autumnal leaf colourations.



Young Festuca Blue Haze (image above), being produced on the nursery. Two other Knoll Gardens selections, Miscanthus Cindy (image below), and Pennisetum Dark Desire (bottom image), have both become great additions to the range of grasses that are available to UK gardeners.