PoinsettIA is Euphorbia pulcheRRIMA. It must be grown in full sun.
If you have aphids, the soil is inadequate, or that pest would not be
attacking it. Plants that are unhealthy, or "under stress", are so because
the soil in which they grow does not fulfill the needs of the soil
organisms. This state engenders in the plant the kind of eletromagnetic
spectrum frequencies that the insect detects, and the message it reads
therefrom is: "This plant is food for you".
You can read the data from Dr. Philip Callahan, recently retired from U
Florida. See pp 263-269 in the Organic Method Primer UPDATE.
A French researcher noted that insect pests check to find out if the
nitrogen in the plant is in the form of proteins, or just amino acids not
yet made into protein.
For aphids, the problem is (pg 308 in Primer) :
"they check out the sap, needing much soluble nitrogen and finding
mostly sugars, so they have to suck up a great deal of sugary sap to get
the protein they need. This is the clue to the imbalanced nutrition
(usually too much nitrogen in proportion). Aphids have to contain
internal microorganisms to make up for that imbalance.....
They eject the excess sugars (as honeydew) they get from the large amount
of sap they have to suck for the protein they need. [Tbis is whre the
black mold fungus thrives).
Aphids thrive and multiply when the nitrogen supplied is too high in
proportion to other nutrients. The yellow component of the
chartreuse-colored shoot tips is what attracts them. Young tissue just
forming gets ost of the nitrogen, and it is in the shoot tips and the
youngest leaves that you see the most aphids.
Such leaves curl up and twist because the cells that should be
expanding the leaf are destroyed or damaged."