It is much easier to prevent problems with indoor plants than it is to remedy problems once they have developed. Through regular inspection of your house plants, and simple preventative measures, you can stop problems before they start, or "nip them in the bud," so to speak. Taking time to give your plants a regular check-up can save you time and trouble, and save your plants from major damage from pests and disease, or even prevent having to throw out plants that are so damaged that they can't be saved.
Start with sterile soil. You can buy sterile compost or potting mix that you know will be pest and disease free to give your plants a good, healthy start. If you prefer to make your own compost, it can be easily sterilized by pouring boiling water into it before you begin planting, to kill any pests or diseases that may have come in with it from outdoors.
Give every new plant a thorough inspection before bringing it into your home. Check for signs of pests and disease that could spread to your other plants and remedy any apparent problems before introducing new plants into your home.
Inspect roots when transplanting. Healthy roots are firm and white. When brown roots are present, leave the plant out of its pot for one to two days, then trim off brown roots and any stems or leaves that show signs of rot. If over half of the roots are brown, hold the soil ball under the tap to remove any compost or soil. Take a sharp knife and cut off all brown or mushy roots. Cut away all stems or leaves that show rot, as well as some of the healthy top growth to balance out root loss. Repot with fresh, sterile compost or potting mix. Water all rot damaged transplants with carbendazim solution. Place pot in a well-lit area that is out of direct sunlight. Water again only when new growth is visible. Do not overwater.
Select plant placement carefully. Avoid putting plants in trouble spots. Plants should not be placed between open windows and doors, near air-conditioning or heating ducts, on top of televisions, refrigerators or radiators, on airy windowsills, with frames that leak, in unlit corners or dark areas that do not receive adequate light, between closed curtains and windows during cold weather.
Spray plants with a mixture of one teaspoon mild dish soap to a gallon of water two or three times a year to repel pests before an infestation can start.
Remove dead flowers and fallen leaves from pots to prevent grey mould, which can spread rapidly in cool conditions.
Act promptly when you do spot trouble. Move plants to better locations or spray, if necessary, as soon as a problem is identified. Many pests and diseases spread or grow rapidly, so quick action could be the difference between saving and loosing a plant, or even several plants, since most problems can spread to surrounding plants, as well. With slow moving pests, such as mealy bug or scale, only the infested plant need be sprayed, however with fast spreading pests, such as aphids, white flies, or spider mites all surrounding plants should be sprayed as well.