BottlebrushCallistemon

SummaryThere are approximately 40 species of Bottlebrushes within the genus Callistemon, and these share many similar characteristics with the paperbark melaleucas, both of which are part of the Myrtaceae family. These extremely hardy shrubs can tolerate a wide variety of soil conditions, and flower most prolifically in a position of full sun. Their natural habitat is along the east and southeast of Australia, but can also be found in the southern part of Western Australia.

Bottlebrushes make a wonderful addition to any garden and are widely sought after for cut flower arrangements. Ranging from crimson reds, bright pinks, oranges and yellows, Bottlebrush flowers are truly distinctive and long lasting. They have no perfume, but are great bird attractors.

As the names suggests, Bottlebrushes are a long, bushy-type of flower, usually around 20cm in length, although this varies from one species to the next. The flowers are Inflorescent: that is, they are made up of many tiny flowers, although they appear as one, and the colour comes from their many stamen rather than their petals, which are tiny. They usually flower from late November through to the end of February, making them a common sight during the east coast summertime. In recent years, bottlebrushes have become a popular choice in roadside landscaping.

MaintenanceCallistemons are so common in cultivation and seem to be present in even the most weed infested and poorly maintained gardens, it could be said that they thrive on neglect. However, that is not quite true. What is true is that many will survive with little or no attention but this is often accompanied by sparse foliage and few flowers. To get the best out of them it is useful to consider the way they grow naturally.Given that callistemons are usually found on moist sites, it should be no surprise to find that they enjoy a reasonable amount of moisture under garden conditions. This does not mean that they require anything like daily watering...once established, they will grow happily with just the occasional watering to help them through dry periods. A sunny position will usually produce the best flowering but plants will tolerate anything except total shade.The use of a slow release fertiliser after flowering will usually be sufficient.

PruningApart from watering, the main concerns for successful bottlebrush growing are pruning, pest control and fertilising.The woody seed capsules that form along the stems after each flowering season can look unsightly particularly as the new capsules follow the previous ones in succession on the same stem. To prevent this, it is usually recommended that plants be pruned annually just behind the spent flowers. This pruning also has the added advantage of stimulating branching leading to a greater profusion of flowers in subsequent years. If a bottlebrush plant has become too large or sparsely branched, it can usually be rejuvinated by severe pruning almost to ground level. The accompanying photo shows a plant of Callistemon 'Captain Cook" producing new foliage after a severe cut back. However, pruning those species which have a weeping growth habit can destroy their shape (e.g.C.viminalis and its cultivars such as "Hannah Ray" and "Dawson River"). Reference: http://www.anpsa.org.au/callis3.html

PestsThere are several pests which can attack callistemons although healthy plants can usually cope without human intervention. Sawfly larvae are an exception - they are common pests. They are bronzy green in colour with a pointed tail and, because they occur in groups, they can inflict a great deal of damage to the foliage quickly. They are best controlled by physically removing them either by hand (using gloves!) or with a jet of water from a hose.Scale is another pest that can be removed by a strong jet of water but this may need to be carried out several times. If this is not successful, the traditional treatment with white oil is usually effective.Another pest that can be troublesome is the webbing caterpillar. These grubs more commonly attack related genera such as Melaleuca and Leptospermum but can cause damage to certain callistemons (the cultivar C."Little John" seems particularly prone). Again, a jet of water is effective treatment.

Flower ArrangementsAs cut flowers, Bottlebrushes have stems of 30 to 60cm in length. If kept cool, and with the addition of a preservative in their water, they can last a considerable length of time. Following their flowering stage, the fruits beneath the petals and stamen also make interesting additions to flower arrangements. Today, most cut flowers come from cultivated field crops grown in Western Australia, New South Wales, Victoria and South Australia.

Cultivationfrom seedAfter flowering, callistemons produce seed capsules in rows along the branches and in the majority of cases the seed remains within the capsules indefinitely and can easily be collected at any time. There are, however, a few species that release seed once it is mature. The popular Callistemon viminalis (weeping bottlebrush) is in the latter category.In the case of species which retain the seed indefinitely on the plant, the capsules need to collected and placed in an open container in a warm position until the fine seed is released. This should occur in 2-3 days. For best results, the capsules should be at least 12 month's old (i.e. the most recently formed capsules are best avoided). With those species which release the ripe seed annually, the plant needs to be kept under observation and seed capsules collected when the capsules commence to open.Germination of the seed of Callistemon species is usually quite easy by normal seed raising methods. No special pretreatment is needed. Germination should occur in 14 to 30 days, depending on the species.

Reference: http://www.anpsa.org.au/callis2.html

Cultivationby propogationCallistemons can be propagated by either seed or cuttings. However, to maintain desirable characteristics of a particular plant vegetative propagation (eg. cuttings) must be used. This also applies to propagation of named cultivars.Step 1Fill a pot with a soilless medium. Prepare the medium from a mixture of about 40% perlite and 60% peat. Add enough water to keep the medium moist but not wet. The precise mixture is not critical, as long as it's kept moist.Step 2Take a cutting of a mature bottlebrush plant in the spring or summer. Cut a shoot from a half-ripe stem that's up to 3 inches long. Cut the shoot off at the stem to get the entire heel. This is the part of the shoot that widens out as it joins the stem.Step 3Plant the bottlebrush cutting. Place the cutting in the pot with the cut end in the growing medium and cover it with a plastic bag. Secure the bag with a rubber band to keep the moisture from escaping. Put the pot in a spot with indirect sun or fluorescent lighting.Step 4Repot the bottlebrush plant once it becomes established. Use a pot with a diameter that's large enough to hold the mature plant. This can vary considerably, so you'll need to know the adult size of your particular species.Step 5Mix a potting soil that consists of two parts humus, one part perlite and one part garden soil. Transfer the bottlebrush plant to the new pot and fill it in with your potting soil. Water the plant thoroughly and allow it to become fairly dry before you water it again.Reference: http://www.gardenguides.com/82751-propagate-bottlebrush-plants-cuttings.html

VarietiesWhite Anzac Bottlebrush - Callistemon citrinus White AnzacA very attractive, dense shrub with oval, green leaves and large, white bottlebrush flowers particularly in Spring and Autumn. Frost resistant.

Up to 1m x 2m.

Callistemon citrinus 'Splendens'This is an upright shrub. The leaves are elliptical and grow to about 9 cm long. New growth is pink. The It produces red bottlebrush spikes mainly in spring, and sometimes at other times. It was registered as a cultivar in 1989.

Up to 3m x 3m.

Callistemon 'Little John'This is a dwarf bottlebrush with a compact and rounded shape and dense blue to green foliage that is delightfully soft and furry. It produces profuse quantities of deep red bottle brushes and is an excellent addition to any rockery, shrubbery or border. Although it prefers full sun it will tolerate part sun but may not produce as many flowers. It will tolerant to mild frosts, sheltered coastal conditions. It makes a great low hedge and can go well in large pots or tubs to make a powerful statement on a patio or terrace.

Up to 1m x 1.5m.

Callistemon pallidus - lemon bottlebrush

A dense erect shrub growing to 3m in height and spreading 2m. Creamy yellow flower spikes are produced in spring and summer.

Up to 3m x 2m.

Callistemon viminalis - Weeping BottlebrushThe Weeping Bottlebrush is a small to medium sized weeping tree with red bottlebrush flowers in spring, with flushes in summer and autumn.

Up to 8m x 3m.

Callistemon Pink Champagne

This is a upright shrub with pink bottlebrush flowers with yellow anthers in spring and autumn. The grey green foliage is fairly hard and lance shaped.

Up to 3m x 2m.

Callistemon - Purple Splendour

This is a dense bushy shrub with clusters of red purple bottlebrush flowers with yellow tipped stamens in spring. There are a number of similar cultivars including Callistemon "Violaceus", "Purple Cloud" and "Mauve Mist“.

Up to 3m x 2m.

Callistemon Pink AlmaThis is a well-branched compact shrub that flowers profusely in spring and again in autumn. The flowers are a lovely bright shade of pink, which fade, giving an interesting two tone look. The blooms are nectar rich for birds and the branches are slightly weeping. Regular pruning will encourage a dense habit. A good hardy plant which suits most soil types. Good for full sun or part shade.Up to 1.4m x 1m.

Callistemon pachyphyllus green

Compact weeping shrub for moist soils in full sun. Many large apple green brushes in spring and autumn. Lovely weeping habit contrasts well with the flowers.

Up to 1.5m x 2m. 

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