What's Wrong with My Plant?: Expert Information at Your Fingertips Pests* Diseases* Common Problems

 

Plant is too close to a source of heat; humidity is too low; overfeeding; plant is in a draught; watering is spasmodic.

 

Water splashes on leaves; sun scorch.

 

Overwatering; sudden drop in temperature; water left lying on leaves at night.

 

Insufficient food; a natural process if it is the oldest leaf.

 

Lack of light.

 

Overwatering; draughts; lack of humidity; change in growing conditions; drop in temperature.

 

 Entire Plant

Normal in winter.

In spring and summer underfeeding or overwatering; plant may need repotting; too little light.

 

In spring and summer lack of light or insufficient food. 

In winter plant too warm or moist for the amount of light available.

 

Too much sun; underwatering; overwatering or overfeeding – indicates root damage.

 

Pot being moved; lack of humidity; overwatering.

 

Overfeeding – plant putting on too much growth; wrong day length.

 

 

70% Neem Concentrate

When maintaining healthy plant growth, if a plant is not looking healthy the first thing to do is to physically check it for pests. Look on the under side of the leaves, along the stems and in the growing tips and flower buds. Sometimes you will be able to eradicate the pests by picking them off the plant, but if there is an infestation it may be wise to take the plant outside and spray it. If this is not possible and you need to spray it inside the house, use a non-toxic spray like pyrethrum, and ventilate the area after spraying.

Other measures are to wash the plant with water to which a few drops of mild dishwashing liquid has been added or apply  Neem Oil.  This is a broad spectrum insecticide/fungicide/miticide which can be used indoors or outdoors on ornamental plants, flowers, vegetables, trees, shrubs and fruit & nut crops.  It controls insects and mites including whitefly, aphid and scale and also controls fungal diseases including black spot, rust, mildew and scab, making it ideal for healthy plant growth in containers.

If you are interested in natural products like Neem Oil you may also be interested in Insecticides of Natural Origin

 Aphids (greenfly)

Soft, green insects which suck the sap of young shoots, buds and the under side of young leaves, causing them to curl and fall. Aphids secrete a sticky substance called honeydew which may get a black or sooty mould growing on it.

Remove and destroy badly distorted plant growth. Wash plants in soapy water or spray with an appropriate insecticide. Keep plants clean at all times.

 

Small insects covered by a white, waxy coating. They cluster in the leaf axils, on the stems and roots and weaken the plant by sucking the sap. They also produce honeydew. Severe infestation can result in total loss of leaves.

Remove visible bugs with a toothpick or a damp cloth, or use a stiff brush dipped in surgical spirit, then spray top growth with a pesticide. Alternatively use granules of a systemic pesticide in the potting mix.

 

These are minute, and not really spiders although an established colony has a very fine silky white web. They suck the sap from the under side of leaves, which then become yellowish and fall off. Infected plants are stunted and may die.

They thrive in hot, dry air, so increase the humidity around the plant, move to cooler conditions and wash the foliage frequently with water. Cut away badly infested leaves and stems and spray with an appropriate pesticide. Repeat the treatment after 3 days and again 10 days later.

  

When mature they are motionless and have a hard waxy shell. They attach themselves firmly to stems or leaves and suck sap, eventually stunting the plant. The honeydew they produce attracts ants

Remove the insects by sponging the stems and leaves with water or a fairly stiff brush dipped in soapy water or a pesticide solution. Then apply the pesticide to the whole plant.

 

Small insects which jump when disturbed. They are sap suckers which attack any fairly soft foliage or flowers, causing mottling, streaking or white spots. Drops of reddish fluid that these insects secrete turn black, speckling sickly leaves or flowers.

After removing damaged leaves and flowers, spray the plant with an appropriate pesticide.

 

Tiny white sap suckers which weaken plants. The adults deposit larvae in large numbers on the under side of leaves where they suck sap and secrete honeydew.

Whiteflies are very difficult to eradicate. Spray with a pesticide, seal inside a plastic bag and leave for twenty-four hours. Repeat at intervals.

 

The opposite of healthy plant growth is disease, which is contagious and results from the invasion of plant cells by fungi and bacteria.  Remove any sickly-looking and dead leaves and flowers as soon as you see them and keep an eye on bruised tissue, as it may become infected.

 

One of the most common causes of disease in container plants is mildew, a fungus disease. You may notice a furry coating on the stems and leaves, which will result in them rotting. In this case when you have removed the rotting plant material you need to give the plant more ventilation and cut back on watering so that the plant will have a chance to get back to producing healthy growth.

 

Some other tactics to help maintain healthy plant growth and prevent disease are to always use sterile potting mix, try not to let water settle on the foliage and flowers, and have plants spaced well away from each other. This last point is hard to achieve if you are putting a mass of plants in a single container, but just be aware that more vigilance is required under these circumstances. If the container is in a position where there is not enough warmth and the plants are suffering because they are constantly damp, it may be wise to move the container to a warmer position so that the plant can produce healthy growth.  This is the real beauty of growing plants in containers - you can adjust their climate by moving them.