Fresh air is also provided by ventilation, which is the opening of either a door or a window in the room in which the plant is growing. Provide summer ventilation for the following plants: Araucaria, Cacti, Fatsia, Impatiens, Pelargonium, Schizanthus, Succulents and Tolmiea.
Guard against draughts, which are air currents moving rapidly and directly across the plants. Do not ventilate when the temperature outside is appreciably less than that of the room.
A change of air will lower the temperature in hot weather and lower the humidity where overcrowded, moist conditions encourage Botrytis. Also the change will strengthen the stems and increase diseases resistance plus remove traces of toxic vapours.
Vapours arising from a number of sources commonly found in rooms have been reported as damaging to houseplants or their flowers. These include coke stoves, dirty oil heaters, fresh paint and ripe apples. Plants with thick leathery leaves are the ones most likely to withstand the effect of these fumes. Once menace has disappeared, plant damaging coal gas has been replaced by natural gas. Tobacco smoke is never present in sufficient amount to be harmful.
One tip to remember is that allowing an indoor plant to grow happily outdoors can also create another problem. Insects that normally would not be present in a controlled environment, so carefully place your indoor plants in an area away from gardens thriving with an assortment of plants. Place the pots and urns in areas near the house or on a patio for a tropical summer look.
Jimmy told me that he sprays all indoor plants after their exposure outdoors and makes certain there are no pests present when he returns the planter to it's winter home. He is insistent upon spraying the plant thoroughly to rid the entire system of any pest or disease. He has spectacular indoor blooms and has spent years perfecting this system.