HOW TO GROW CALLISTEMON CITRINUS 'Splendens'

Red flowers of Callistemon citrinus 'Splendens'
How to grow Callistemon citrinus 'Splendens'


Callistemon species and cultivars are among the most spectacular and exotic of ornamental garden shrubs. Of which Callistemon citrinus 'Splendens' is one of the most popular and rightly so. Commonly known as the 'Crimson Bottlebrush', Callistemon citrinus 'Splendens' is an attractive evergreen shrub whose origins are found in New South Wales and Victoria in Australia.

The original species was first brought back to England in 1771 by British naturalist and botanist Sir Joseph Banks (1743 – 1820). However it was much later in 1925 that the 'Splendens' cultivar appeared, first named and formally described in Botanical Magazine. In 1970 its cultivar name was subsequently changed to 'Endeavour' in honour of the ship commanded by James Cook. This was one of several botanical name changes made as part of the bicentennial celebrations of his voyage to Australia. For those of you who are interested, the genus name is a combination of the Greek word 'kallistos' meaning beautiful and 'stemon' meaning stamen.

Close up of Callistemon citrinus 'Splendens' red flowers
How to grow Callistemon citrinus 'Splendens'
It is a vigorous, spreading shrub of medium size and a more compact form of the original species. The narrow, rigid leaves are lemon-scented when crushed hence the species name. Under favourable conditions you can expect Callistemon citrinus 'Splendens' to reach a height of approximately 1.5-2 metres. The brilliant blooms are made solely from stamens and appear in succession over the summer from June. As exotic as it looks it has proven to be perfectly hardy along the south coast of England and Ireland, although further north it will require the protection of a sheltered south wall and some horticultural fleece to be on the safe side.

The best time for planting Callistemon citrinus 'Splendens' in during April and May to make the most of the growing season and to allow the roots to establish before the onset of winter. It will perform well in most ordinary garden soils so long as it is moist yet well-drained and in a sunny position sheltered from strong or cold winds. As implied it is tolerant of light frosts and salt spray. When planting in more northerly regions provide the sheltered protection of a south-facing wall. A couple of layers of horticultural fleece would be beneficial over the winter. In areas which are prone to extended periods of freezing conditions grow Callistemon citrinus 'Splendens' as a container plant so that it can be brought in under protected conditions over the winter.

Pruning isn't really necessary except to remove errant, diseased or damaged wood. You can remove the spent flowers structures but avoid cutting into leafless stems.

Callistemon citrinus 'Splendens' received the Award of Merit in 1926 and the Award of Garden Merit in 1993 from the Royal Horticultural Society.

Image credits: Simon Eade gardenofeaden@gmail.com

For related articles click onto the following links:
BANKSIA COCCINEA
HOW TO GROW BANKSIA HOOKERIANA 
HOW TO GROW CALLISTEMON 'Captain Cook'
HOW TO GROW CALLISTEMON CITRINUS 'Splendens'
HOW TO GROW CALLISTEMON VIMINALIS
WHEN AND HOW TO PRUNE BACK BOTTLEBRUSH PLANTS

HOW TO GROW CALLISTEMON 'Captain Cook'


Red blooms of Melaleuca viminalis 'Captain Cook'
How to grow Melaleuca viminalis 'Captain Cook'


Now reclassified and correctly known as Melaleuca viminalis 'Captain Cook', Callistemon 'Captain Cook' is a selected seedling of Callistemon viminalis discovered in Queensland, Australia with a dwarf and bushy habit and considerably more floriferous while young. It was originally sold as Callistemon viminalis 'Compacta', but the cultivar name was changed to 'Captain Cook' in 1970 in honour of the bicentenary of Captain James Cook's voyage to Australia. Since then it has becomes the world's most popular and widely sold form of all Callistemon species and cultivars.

Emerging red stamens of Melaleuca viminalis 'Captain Cook'
How to grow Melaleuca viminalis 'Captain Cook'
It is a dense, slightly weeping evergreen shrub which under favourable conditions will reach a height and spread of between 1.5–2.5 metres. The bark becomes fissured with age while the narrow lance-shaped leaves are approximately 50 to 60 mm long and emit a lemon-like fragrance when crushed.

The bright red, flowers are reminiscent of a bottlebrush (hence the common name of 'Bottlebrush') appearing from early June with further blooms sometimes occurring in late summer or autumn. The eye-catching inflorescences are actually prominent bundles of long stamens!

In its native habitat the original species is usually found along water courses on soils over sandstone or granite so when planting as a garden specimen best results are achieved by providing a moist well-drained neutral to slightly acidic soils. Avoid areas prone to waterlogging and be aware that Callistemon viminalis has proven to perform poorly when grown on thin soils over chalk.

In northern European climates Callistemon 'Captain Cook' is perfectly hardy in the milder regions such as southern England and Ireland. Plant in full sun, but further north it will require the shelter of a south-facing wall as well as some winter protection by way of several layers of horticultural fleece. In regions which regularly experience ongoing freezing temperatures Callistemon 'Captain Cook' is probably best grown as a container specimen so that it can be brought in under protection during the winter.

Prune back lightly after flowering but only to just behind the spent flower structures. Avoid cutting into leafless wood.

Main image credit: Geoff Fox https://creativecommons.org/licenses/by/3.0/deed.en
In text image - Simon Eade gardenofeaden@gmail.com

For related articles click onto the following links:
BANKSIA COCCINEA
HOW TO GROW BANKSIA HOOKERIANA 
HOW TO GROW CALLISTEMON 'Captain Cook'
HOW TO GROW CALLISTEMON CITRINUS 'Splendens'
HOW TO GROW CALLISTEMON VIMINALIS
WHEN AND HOW TO PRUNE BACK BOTTLEBRUSH PLANTS

PLANT LISTS FOR THE DAIRY TREE FERN DESIGN

Dicksonia squarrosa
Plant Lists

Tree ferns have proven to be tough as old boots, capable of growing in deep shade to full sun so long as they have enough water. They are not particularly prone to any pests or disease. As the garden is maintained periodically I would recommend the use of drip irrigation to ensure that these plants do not dry out. Liquid soluble fertilisers can be applied as often as you like to improve the size and condition of the canopy. Prices start from £99.00 to as much as you would like to spend, however I would avoid Haskins as their stock appears to be double the prices of anyone else. Mail order prices are competitive but you do not get to see what you have bought until its arrives in the post.

Dicksonia antarctica
Apart from the tree ferns, all of the ground floor plants will need to be shade tolerant. The selection I have chosen specifically have bright, or eye catching foliage to help maintain interest in the lower light levels below the canopy.

Dicksonia antarctica and the slimer Dicksonia squarrosa are the forms to choose from.

Dicksonia squarrosa does not seem to be available anywhere except from Trevena nurseries. You will need to call for current availability. Their website isn't working properly either but it appears that you will need to contract a courier to collect. Availability should return next spring.

Hosta cultivars

Hosta 'Patriot'
The chosen cultivars will be those with specifically bright variegation such as Hosta ‘Patriot’, White Feather and Autumn Frost. Availability is extremely variable and while there are hundreds to choose from only a dozen or so cultivars at best are on display in the garden centres at any one time. Prices vary from £7.99 to £14.99 per plant depending on size and quality of the cultivar. Specific forms may need to be mail ordered from online specialists.

Slug and snail damaged on Hostas will need to be managed.

Brunnera cultivars

Unlike Hostas there are only a few good cultivars suitable such as Brunnera macrophylla 'Alexander's Great', Jack Frost and my favourite Brunnera 'Looking Glass'. They cannot be grown in the sun as they will scorch and almost shine when planted in shady borders.

Availability is generally good while slug and snail damage will need to be managed. Unlike hostas which only produce new foliage in the spring Brunnera will often produce new foliage if the spring growth becomes eaten. 

Priced range from £ 7.99 to £ 12.99

 Japanese painted ferns

These are starting to be seen more and more in the shops but for specific varieties like the gorgeous Athyrium niponicum 'Ursula's Red' they will probably need to be obtained online. However I have seen them for sale periodically at Haskins, prices are between
£ 6.99 to £ 14.99.

These are very easy to grow if not a little slow but they have proven in my garden at least to be extremely resilient so long as they ground is kept moist.

Regular Ferns

For the traditional green ferns I am looking at the hardy, mostly evergreen ferns with a good range of architectural foliage.  Asplenium - Harts Tongue Ferns are particularly unusual, Dryopteris forms are nicely compact and Polystichum have great sword like foliage. They are mostly left unharmed by slugs and snail although Asplenium are known to be damaged if unprotected.

Ferns have been popular in this country since the Victorian period and so long as the soil is kept moist, especially during the first summer of planting they should be trouble free. To improve the looks remove old growth in the spring.

Substitutions

Heuchera

Heuchera cultivars
If any of the proposed selections offend your eye then don’t worry as there are two further shade tolerant foliage plants that can be substituted – cultivars from the genus Heuchera and Pulmonaria.

Heucheras come in some fantastic colour morphs but were not considered in the initial design as they can be temperamental in their vigour. However if they are ‘happy’ where they are planted then they will perform as excellent specimens. Prices range from £5.99 to £9.99 per plant depending on colour form and size.

Pulmonaria

Some of the lungworts also have some decent foliage and also attractive pink and blue flowers in the spring. Some forms such as Pulmonaria ‘Moonshine’ and 'Apple Frost' have excellent foliage but they were not in the original design as the foliage on Brunneria is better although the blooms on Pulmonaria are more attractive. The foliage can also 'tire' as the season progresses, but this is not a big problem as they will die back in the winter to provide fresh growth in the spring. Prices from £ 6.99 - £ 9.99.

Flower colour

Hosta blooms
Plants with excellent flower colour that thrive in shade are relatively limited however I have listed a suitable section which can be planted at the edges of the bed. All will be spring flowering.

These are not showing in the initial planting design as they are too small to show effectively. 

Note that Hostas also are in the initial design and will produce attractive bell shaped blooms which appear in July

Snowdrops

Snowdrops are early spring flowering and can be purchased as bulbs in the autumn or as pot grown plants in the spring.  Prices are approximately £ 1.99 for a bag of bulbs or 1.49-1.99 for a pot.

The bulbs should be planted as soon as they are available in the shops as they tend to dry out, affecting the quality when they sprout out in early spring. Although more expensive snow drops are best purchased as pot grown in the spring


Anemone blanda – the wind flower

Like the snowdrops, Anemone blanda is spring flowering and can be purchased as bulbs in the autumn or as pot grown plants in the spring.

Once established, Anemone blanda can be lifted and planted elsewhere in the bed or larger garden

Prices are approximately £ 1.99 for a bag of bulbs or 1.49-1.99 for a pot.

Hellebores

Hellebores cultivars now have some fantastic blooms although the foliage will become dull and tired for the rest of the year once the blooms have finished. The blooms are long lasting and to improve their show the previous season's foliage can be removed.

However there are a few forms with some foliage colour such as Helleborus x 'Penny's Pink' Prices £ 7.99 to £12. 99

The more commonly found Hellebore white Christmas rose may be preferable as the flowers will stand out far more in the shade. Prices start from £ 4.99 - £ 7.99

Cyclamen Laser

Available from the end of November, Cyclamen laser are surprisingly hardy however they are forced into bloom in the nurseries over the winter.

These will usually flower in Feb-March and so when purchased they will need to be hardened off of 10-14 days or so before they can be planted outside.

Usually £ 1.99 for a small pot.

Slug and Snail control

The most effective method of snail control is the blue metaldehyde pellets, however these are still not 100% effect. Therefore I would recommend using two or more methods of control such as beer traps, environmentally sensitive pellets and sacrificial plants such as lettuce. When using sacrificial plants the slugs and snails can then be collected and disposed of in a fashion that suits.

The following article may be of further interest:

WHAT ARE THE SAFE ORGANIC ALTERNATIVES TO SLUG PELLETS