New Guinea impatiens (Linearifolia hybrida) is an attractive flowering plant that you can grow as an annual in all climate zones and as a carefree perennial in areas that receive no frost. Coming from the island of New Guinea, north of Australia, this plant often has multi-colored leaves that add to its visual appeal in the garden. It is more tolerant of full sun than other species of impatiens---it needs more sun in order to bloom.
Delay fertilizing your New Guinea impatiens for the first two weeks after you plant it. Be sure to keep the soil moist, whether you are growing your impatiens in a pot or in a garden bed.
Feed your plant with 100 ppm (parts per million; see Resources) nitrogen twice each week for two weeks. Water your plant between fertilizer applications if the soil is dry.
Fertilize with 200 ppm nitrogen twice each week from then on. Water your plant between fertilizer applications if the soil is dry.
If you see signs of a magnesium deficiency, which causes die back of shoots and stunted upper leaves, use 8 ounces of magnesium sulfate for each 100 gallons of water once a month. For 25 gallons of water, use 2 ounces of magnesium.
Fertilize with fish emulsion if you prefer to use a more natural plant food. Follow the instructions on the label.