Germination temperature
Mild to warm; sow in spring or summer with a little warmth.
Tree growing guide
Weeping bottlebrush is an Australian small tree with drooping branches and bright red flower brushes, also sold as Callistemon viminalis. Its dust-fine seed needs no treatment but must be surface-sown and watered from below; this guide shows how.
Mild to warm; sow in spring or summer with a little warmth.
Surface: press the seed onto the mix without covering it.
About 2-3 weeks.
Leave seed uncovered on the surface; grow seedlings in bright light and later full sun.
None needed; just release the seed from the woody capsules.
Sow in trays or pots and prick out; do not direct sow such fine seed.
The seed forms in small woody capsules, 5-6 mm (about 1/4 in) across, clustered along the stems, and each capsule holds many tiny seeds. If you have unopened capsules, put them in a paper bag in a warm, dry place until the fine seed falls out. Seed falls readily from mature capsules once they are dry. Mix the dust-like seed with a little fine dry sand so it can be spread evenly.
Not needed. Bottlebrush seed has no hard coat and germinates easily.
Not needed. There is no cold requirement.
Not needed, and impractical: the seed is so fine that it clumps and is lost in water. Moisten the sowing mix instead.
Sow in spring or summer. Bottlebrush seed needs only a little warmth; in India, sow after the hottest weather or in the cooler months when trays will not dry out.
Do not bury it. Sprinkle the seed over the surface of a moist mix and press it down firmly, without covering it.
A freely draining seed-raising mix. The Australian Native Plants Society suggests about 80-85% washed river sand with 15-20% peat moss or a peat substitute; a good commercial seed mix also works.
Water from below so the seed is not washed away: stand the pot on a capillary mat or in a saucer of water, or use a very fine mist. Never let the surface dry out until seedlings are established.
Keep the uncovered seed in a bright spot out of harsh midday sun. Seedlings need good air circulation and shelter while small.
Seedlings usually appear in about 2-3 weeks.
Prick seedlings out into individual small pots when they can be handled, usually when the second pair of leaves appears. Where seedlings are crowded, thin them by snipping out extras so the strongest remain.
Grow young plants in moist, well-drained mix in full or part sun and plant out once well rooted. Young plants are susceptible to frost damage while small, so shelter them in cold areas.
Cause: the seed was covered too deeply or washed away by overhead watering. Fix: resow on the surface, press in and water only from below.
Cause: bottlebrushes hybridise readily, so seedlings vary in habit and flower colour. Fix: expect variety from seed; use cuttings when you need an exact copy of a named form.
Cause: a constantly wet, stuffy surface. Fix: use a sandy, free-draining mix, improve air circulation and thin crowded seedlings.
Cause: frost; plants may be damaged by moderate to heavy frost, and young plants most of all. Fix: protect young plants in winter in frost-prone areas.
In the wild it grows along watercourses in eastern Australia. It performs best with a reliable water supply but tolerates dry spells once established, prefers medium to heavy soils, copes with imperfect drainage and flowers best in full sun.
Light pruning after flowering removes spent brushes and keeps a good shape; hard pruning can spoil the weeping habit.
It produces abundant tiny seed spread by wind and water. A University of Florida risk assessment rates it as high risk, and it is a declared invasive species in parts of South Africa. Avoid planting it next to streams or natural bushland, and check local rules.
It responds to a light annual feed after flowering.
Surface-sow the fine seed in spring or summer and water from below for red-flowered weeping trees.
Not at all. Sprinkle the dust-fine seed on the surface of a moist, sandy seed mix, press it in and water from below.
Yes. Botanists now include Callistemon in Melaleuca, so the accepted name for weeping bottlebrush is Melaleuca viminalis; Callistemon viminalis is still widely used in nurseries.
Not always. Bottlebrushes cross readily, so seedlings vary; named cultivars are grown from cuttings.