A few simple precautions and remedies ensure your house plants remain in the best condition.
In addition to benefiting from correct feeding and watering, house plants have specific needs for heat, lights and humidity. If kept in ideal conditions, they provide a long lasting display of healthy flowers and foliage. Plant needs vary, and basic care information is usually given on labels inserted into the pot. The following general guide to common plant problems is useful if your plants begin to look unhealthy.
The right temperature:
- Temperature needs are seasonal and reflect a plant’s natural growth cycle. Usually this means active growth during the spring and summer months and dormancy in the autumn and winter months. Provide warmth for most actively growing and flowering house plants, and cooler temperatures for dormant one. House plants, such as Italian bellflower, that lose their leaves when dormant need quite cool temperatures.
- Provide cool but frost-free temperatures for winter flowering hardy or nearly hardy house plants such as azaleas, polyanthus, forced hyacinths and daffodils, to prevent premature withering of the blooms.
- House plants are more liable to suffer from too much heat than too little – particularly in houses with central heating during the winter. If in doubt, lower the temperature or move the plant to a cooler position.
- Keep house plants well away from direct sources of heat such as radiators and central heating ducts.
- Try to avoid wildly fluctuating temperatures, though a drop in night temperatures is often beneficial, especially in winter. Don’t move house plants between rooms of very different temperatures.
- House plants left on windowsills at night in cold weather can occasionally suffer from frost damage, especially if the plant is behind closed curtains that prevent any heat from reaching it.
- Provide drought free ventilation, particularly in hot weather.
The right light:
- Display cacti, succulents such as Aloe vera varieties and most plants with furry, gray or waxy leaves in plenty of direct sunlight all year round.
- House plants need more light when in bud or flowering than when resting, so move them closer to a window, if necessary.
- The thinner the leaf, the more you must protect the plant from direct sunlight. The delicate leafy fronds a maidenhair fern, for example, shrivel up when exposed to direct sunlight for long periods.
- Provide plenty of light for colored leaved and variegated house plants. Prolonged exposure to direct sunlight scorches or bleaches the white or yellow leaf area in some varieties.
- To prevent lopsided growth towards the light give house plants growing near a directional source of light such as a window a quarter turn every few days.
- In winter, when light levels are low, move light tolerant house plants closer to a window.
- In summer, only cacti and some succulents can stand the intense light on a windowsill that’s gets full sunlight. Move other house plants back or shield from sun with netting or blinds.
- House plants benefit from being put outdoors in summer, in a sunny or shaded spot as appropriate.
- Shrubby flowering plants such as oleander benefit from sunlight ripening the wood, which encourages flowering during the next season.
The right humidity:
- The thinner the leaf, the more humid the conditions the plant likes, especially in high temperatures.
- Group humidity loving house plants together to create a beneficial humid micro-climate.
- Place a humidity love plant on a pebble-filled tray or shallow dish kept topped up with water.
- Use mist sprayers often to spray leaves of humidity loving house plants.
First aid for plants:
Symptoms often have several possible causes, making diagnosis largely a process of elimination. If two or more symptoms occur together, check each cause in turn to find out which of them might apply and correct appropriately. Whatever the problem, the quicker you act, the more likely it is that the plant makes a full recovery.
Slow or no growth:
Symptoms are very slow or no growth in the growing season. It may be caused by; too little light – move the plant closer to the window; too little food – increase feeding; too little water – increase watering; overcrowded roots in worn-out potting compost – re-pot your plant into a larger pot with fresh potting compost.
Symptoms are small pale leaves and lanky growth with long gaps between leaves. This may be caused by; too much heat and water in the dormant season – cut back to compact growth, move to a cooler spot and reduce watering; too little food in the growing season – increase feeding; too little light – move the plant to a brighter position.
Poor leaf color:
Symptoms are loss of leaf color or variegation. This is caused by too little light. To remedy this move the pot to a brighter spot.
Brown leaf edges:
Symptoms are brown leaf tips or edges. This may be caused by; dry air, if so increase humidity; bruising or contact with windows – move to a spot where there is more room; too much water – decrease watering, re-pot if potting compost is saturated; too little water – increase watering; too much light – move to a shadier position; too little light – move to a sunnier spot; too much heat – reduce temperature or move to a cooler spot; too little heat – increase temperature or move to a warmer spot; dry air – increase humidity; drafts – move to a sheltered location; too much food – stop feeding.
Symptoms are wilted leaves which may be caused by: too much heat – lower temperature or move to a cooler spot; dry potting compost – water thoroughly; waterlogged potting compost – re-pot in fresh compost and water lightly; too much light – move to a shadier spot; dry air – increase humidity; overcrowded roots in stale compost – re-pot in larger pot with fresh compost.
Leaf or bud drop:
Symptoms are sudden leaf or flower bud drop. This may be caused by: exposure to direct drafts – move to a sheltered position; rapid fluctuation in temperature – in winter, newly bought plants may drop leaves or buds in response to temperature changes between the shop and home; too little water – water thoroughly; dry air – increase humidity; too little light for flowering – move to a brighter location.
Poor or no flowers:
Symptoms are small, pale or absent flowers on mature flowering plants in season. This may be caused by: too little light – move closer to window or move outdoors to ripen wood in summer; dry air – increase humidity; too much food – stop feeding; too much re-potting – some plants resent root disturbance and flower best when pot-bound.
Symptoms are flower fading prematurely. This may be caused to: too much heat – lower temperature or move to a cooler spot; too little water – increase watering; too much light – move to a shadier spot; dry air – increase humidity.
Rotting leaves and stem:
Symptoms are leaves and stem rot which is usually caused to too much water and leaves being left wet. To remedy this reduce watering and dry leaves after spraying.
Yellow lower leaves:
Symptoms are lower leaves turning yellow prematurely and dropping. Over watering and drafts may cause this so reduce watering, re-pot if the potting compost is saturated and move to a sheltered position.
Brown lower leaves:
Symptoms are lower leaves turning brown and falling. This may be caused to too much heat – reduce temperature or move to a cooler spot; too little water – increase watering; too much light – move to a shadier position.
Green slime on clay pot:
This green algae on the side of a pot is caused by over watering or blocked drainage.
White crust on clay pot:
This chalky white deposit on the side of a pot is caused by hard water and over feeding.