Houseplant care – watering and feeding

House Plants – How to care for your house plants: watering and feeding

There is a lot of unnecessary worry associated with houseplants, but there needn’t be. Most of them require nothing more than watering, feeding and occasionally potting on.

Watering House plants – The most useful piece of equipment is going to be the watering can. Try to get one with a narrow spout. Plants will die if they are given too much water, and also if they get too little. There is no hard and fast rule covering all plants, but a general approach is the finger test. If you insert your index finger into the soil up to the first joint, and the soil feels damp, then don’t water it, but if it feels dry, do! When watering, fill the pot until you see the water bubbling out of the drainage holes. Leave the plant for a few minutes to absorb the excess water and remove any that is left. Some plants, such as African Violets prefer to be watered from below, but again, wait until all excess is taken up. Another important aspect of watering is to ensure that the water is at room temperature. Fill the can the night before and allow it to come to room temperature, to avoid shocking the plants. 

Feeding House plants– Plants that have been freshly potted will not require feeding for the first few months, while they are forming new roots. There are a few simple rules to apply to feeding. Food that is purely for foliage plants, such as Weeping Fig, needs to be high in nitrogen, usually indicated on the container by the letter ‘N’. For flowering plants, such as Begonia’s, you should look for K2O, which indicated high levels of potash. Slow release fertilisers can be incorporated into the compost. Some plants require specialist feeds, such as Orchids or Cacti. Feeding also tends to take place from early spring to late summer, whilst the plants are in active growth, and should be stopped in the winter.
Light For House plants- Each plant will have its own light needs, and it is worth referring to the label for that detail, or suitable books, but the following can be used as a guide:

House Plants For Different Locations And Conditions

Shade Good distance from a window, but enough light to read by Aspidistra, Sanseveria
Semi-Shade Either close to a window that doesn’t receive sunlight, or some distance from a sunny window Dracaena, Spider Plant
Bright, no sun On a sunless windowsill, or close to a bright window Bromeliads, Cheeseplants
Some direct sun On or close to east or west facing windowsill’s, but protect from hot summer sun. Impatiens, Saintpaulia
Sunny window In direct sun, or close to a southfacing window. Shading may be required in the summer Bougainvillea, Hibiscus

Temperature For House plants– Again, you will need to refer to the needs of the individual species as to their particular wants. Most plants will thrive in a temperature range of 15 – 250 C (55-750 F). Houseplants will tolerate temperatures a bit above or below this range, but do not enjoy real fluctuations, so they can take a small and gradual drop overnight, rather than a sudden fall. Keep plants away from windowsills, radiators and draughts to prevent these sudden changes. As ever, there are exceptions to these rules, and cacti and succulents are well able to cope with a wide range of temperatures, similar to their growing conditions in the wild.

Humidity For House plants – Most houseplants require a degree of humidity for optimum growth. Unfortunately, modern central heating has created very dry atmospheres to grow plants in. To compensate for this, there are a number of tricks to increase humidity. The most popular method is to place pots on trays containing gravel, aggregate or shingle, that are kept moist, allowing humid air to rise up amongst the plants. A second method is to place one pot inside a larger one, and fill the gap with compost or stones, again kept moist. This also helps to prevent the compost drying out. Grouping plants together helps to raise humidity, with the plants creating their own ‘micro’ climate. You can also spray the plants once or twice a day with water using a mist sprayer, depending on the temperature. However, bear in mind that the warmer the room, the more humidity and spraying will be needed, and the cooler, the opposite.

Repotting for House plants – Most houseplants will grow a lot better if they are regularly potted on into larger pots. If they become potbound, their growth rate will rapidly decrease. As ever, there are exceptions to this, and some plants prefer to be left to avoid root disturbance, or because they have a small root system. Examples of these include Bromeliads, African Violets, Peperomias, many of the Begonias grown for foliage and the cacti and succulents. Try to pot on plants in spring as the new growth is beginning. You will know if the plant needs repotting by turning the pot upside down, tapping it to release the plant and inspect the roots. If all you can see are roots, then it is time to pot on, otherwise leave it in the same container. In general, you need to move onto the next sized pot up, for example, from a 5″ to a 6″ pot. Use a similar compost to the one the plant is in, and incorporate drainage in the base of the pot. Some plants require specialised composts, such as orchids, cacti and so on.