Germination temperature
Warm conditions; sow in spring or early summer, or in the warm season in the tropics.
Tree growing guide
Weeping wattle is a fast-growing southern African shade tree with feathery leaves and upright sprays of bright yellow flowers that bees love. Its seed is easy to raise after an overnight hot-water soak; this guide covers that treatment, a simple sowing mix and early frost protection.
Warm conditions; sow in spring or early summer, or in the warm season in the tropics.
Shallow: cover with about twice the seed's thickness of sandy mix.
Seed sprouts readily once it has swollen after soaking.
Not needed for germination; seedlings need full sun.
Pour hot water over fresh seed and leave it to soak overnight.
Raise in pots or seed trays; young plants transplant well.
The seeds are borne in thin, flat, dark brown pods about 100 mm (4 in) long that taper at both ends. Seed is large and variable, roughly 1,200-3,300 seeds per kg. Use fresh, plump seed and discard any with insect holes.
Like many pea-family trees it has a hard coat that keeps water out, so the hot-water soak below is the scarification step. If some seeds have not swollen after soaking, rub them gently on fine sandpaper to thin the coat and soak again.
Not needed. This is a savanna tree with no cold requirement.
South Africa's National Biodiversity Institute (SANBI) advises placing fresh seed in hot water and leaving it overnight. The Australian Native Plants Society describes the same method for hard-seeded legumes: cover the seed with boiling water, leave to stand overnight and sow the seeds that have swollen to about 1.5-2 times their original size. Treat the unswollen ones again. Seeds that float are usually not viable.
Sow in warm weather. In cooler climates start seed indoors in spring or keep trays in a warm, bright spot.
As a general rule for seed this size, cover it to about twice its own thickness with the sowing mix.
SANBI recommends a 5:1 mix of river sand and compost. The tree grows best in well-drained soil, so avoid heavy, wet mixes.
Keep the mix moist but never soggy while the seeds germinate. Swollen seed rots in waterlogged trays.
Not needed for germination. Move seedlings into full sun as they emerge.
Soaked seed sprouts readily in warm conditions. Seeds that stay hard can be nicked and soaked again.
Pot seedlings on individually once they have their first true leaves. Young plants transplant well; plant out in full sun in well-drained soil at the start of the warm or rainy season.
Growth is fairly fast, about 1-1.5 m (3-5 ft) a year. Young trees are frost-tender for the first 2-3 years, so cover them on frosty nights or keep them in pots under shelter until they are larger.
Cause: the hard coat did not let water in. Fix: repeat the hot-water soak, or rub the seed lightly on sandpaper and soak again.
Cause: frost damage; young trees are frost-tender for their first 2-3 years. Fix: protect them with frost cloth or grow them in pots under cover until established.
Cause: communal caterpillars spin large masses of grey silk on the tree. Fix: cut out and destroy small webs on young trees; established trees usually recover.
Cause: frog-hoppers (spittle bugs), which give the tree its other name, rain tree. Fix: no action is usually needed; avoid parking or sitting under the tree in summer if the drips are a nuisance.
Native to dry bush, savanna and wooded grassland in southern Africa, it is fast-growing and drought resistant once established, and its roots are not aggressive, which makes it a good garden, street and shade tree.
The flowers produce plenty of nectar and pollen, and livestock eat the young leaves and pods.
It grows mostly on well-drained sandy loams, loams and clay loams. Avoid low spots where water stands after rain.
The seed is orthodox: dried to a low moisture content and kept sealed at room temperature, it stayed viable for 3 years.
Soak the seed overnight in hot water and sow in warm weather for a fast, bee-friendly shade tree.
Pour hot water over fresh seed and leave it to soak overnight, then sow the seeds that have swollen. Re-treat any that are still hard, or nick them lightly with sandpaper.
No. Despite the name, Peltophorum africanum is a different genus of the pea family and is not closely related to the true wattles (Acacia).
Established trees cope with light frost, but young trees are frost-tender for their first 2-3 years and need protection.