The common yellow Allamanda plant is Allamanda cathartica. Allamanda blanchetti is the red Allamanda and the Allamanda nerifolia plant is the dwarf shrub form.
Allamanda cathartica, is an evergreen vine which produces 5 inch long trumpet flowers all summer long. Each flower consists of 5 overlapping petals and emits a vanilla perfume. The blooms form in racemes at the tip of each stem.
You can certainly grow A. cathartica in smaller containers than these, but doing so will restrict the size of the vine.
Wear long sleeves and gloves when pruning this plant as any broken stem will bleed amilky latex which can irritate your skin if it gets on you.
In Suriname where it occurs along the river banks, Allamanda is used to treat jaundice, malaria and constipation.
I don't recommend ingesting any part of the plant as it is considered to be poisonous. Visit this NCSU poison plant page for more in-depth information.
Yellow Allamanda also grows wild along the waterways of Brazil and Guyana. It is hardy from zones 9b-11. In zone 9b you can expect some leaf damage when temperatures fall below 30 degrees F.
Plant the vine in full sun on rich, moist soil. Keep it watered in the summer months. Prune it after it finishes flowering.
Remove a few of the main stems to make room for fresh ones. Then head the laterals back to within 2 nodes of the main stems.
The yellow flowers are followed by spiny capsules which split open when the winged seed inside them is ripe. You can use these seeds to start new plants or take cuttings of mature wood.
This Allamanda vine has been pruned into a hedge.
Allamanda nerifolia syn. Allamanda schotti
This is a 3-5 foot tall shrub which will occasionally send up a long, viney stem.
It does not require much pruning but you will need to trim back these rebellious stems periodically.
The 1.5 inch long blooms of Allamanda schotti are pint-sized replicas of those of A. cathartica.
The foliage is also smaller than that of Allamanda cathatrica or Allamanda blanchetti.
This species is also more tolerant of dry soil than either of the others.
The violaceas differ from A. cathartica only in flower color. There are many cultivars blooming in a range of colors from cream infused with burgundy to hot pink. Most have names like 'Black Cherry' or 'Cherries Jubilee'.
They are sometimes referred to as the pink, purple or red Allamandas.
Here, a pink Allamanda plant grows in a pond at Longwood Gardens.
If you live above zone 9b you will need to overwinter your Allamanda plant indoors.
Plant it in a large tub of high quality potting mix. Keep it moist during the summer heat, nearly dry in the winter.
Its need for intense light may make it difficult to grow outside of a greenhouse. If you have a greenhouse, this twining vine would be stunning trained up a wall and allowed to cascade from the ceiling. The vanilla fragrance would be intoxicating inside an enclosed space.
You may need to run a humidifier to provide it with the humidity it wants. This is less necessary in the winter.
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