What does amonia do for houseplants?

Answer 1

From OSH:

"Ammonia. Household ammonia is used to control many insects, but refrain from use in hotter weather. Ammonia may injure the leaves of some plants so test before usage."

From Maas Nursery:

"Ammonia in direct contact with plant roots can cause damage and must be avoided. "

However, remember that fertilizers like Miracle-Gro have "1.2% ammoniacal nitrogen", which is a form of ammonia that is useful to the plants as it gives them needed nitrogen. There is even a recipe for home made fertilizer containing ammonia at the last link below. But it is a VERY small amount, mixed with other things it will react with to make it safe.

Hope this helps!

Answer 2

Its a cheap source of nitrogen. N is needed for foilage growth. Don't use cloudy ammonia, it contains soap. Dilute it 50:1 with water and use sparingly or you'll "burn" the roots and kill the plant.

Answer 3

Provides a nitrogen source.