Injecting life into indoor plants

Waimarino Bulletin, Volume 3, Issue 21, 15 October 1985, Page 10

Injecting life into indoor plants

The cool cloudy weather having dimmed my enthusiasm somewhat for working outside, I decided it was time to direct my attention to the plants inside, and to re-pot some which were showing signs of needing attention. Most house plants, although by no means all, benefit from a change of growing medium and a larger pot at least once a year, preferably at the beginning of the growing season when fresh growth appears. As the plants grow larger, the roots take up more and more of the pot space and the growing medium disintegrates. No amount of supplementary feeding will make up for the lack of a good base medium to nourish the plant through its rooting system. A larger pot is not always necessary. Plants should not be 'over-potted', that is put into a pot several sizes too large for its needs. Where there is a mass of small root growth showing on the surface of the soil, or roots are protruding through the drainage holes at the base of the pot, it is a good guide that the plant needs I fresh soil. Sometimes it is not easy to see if a larger pot i is necessary, and to deterj mine this it is necessary to ; remove the plant from the pot. To do this place two fingers, one each side of the main stem of the plant, and the palm of the hand flat

against the top of the soil. Turn the plant upside down and tap the base of the pot sharply and it should slide out quite easily. If the plant is dry, watering an hour before removal will make the process easier. Once removed, if there is a tight mass of roots round the growing medium, your plant needs the next size in pots. Place some small stones in the base of the pot around, but not over the drainage holes, and use sufficient potting mixture in the base so that the base of the stem of 1 the plant is about half an inch from the top of the pot. Fill the sides of the pot with the mixture pressed down with your fingers, or if there is not sufficient room, the blunt end of a pencil will do the trick. Water well to remove air pockets from the soil and allow to drain thoroughly before putting the plant back into position. If the plant shows no sign of root mass on the outside of the soil, it does not need a larger pot, but will benefit from some fresh potting mix. On removal, check the base of the plant for insects as these will feed on the roots causing debilitation of the plant. Also check that the soil is not waterlogged and smelling sour. If either of these conditions are present, wash all the old pot mix away from the roots in a bucket of tepid water and either re-pot in a new pot of the same size, or if the same pot is used, scrub in hot water and detergent

and rinse thoroughly. Check and remove any dead or damaged roots before placing in the new pot. If the earth medium around the roots seems to be clear of pests and the plant healthy, gently crumble away some of the old growing medium from the sides and the base, being careful not to disturb the medium around he root ball, and repot as above in a clean pot. If you are re-potting into a container with no drainage holes' it helps to put some broken charcoal in a layer just above the gravel or stones in the bottom of the container, as this will help to keep the soil sweet. Care must be taken not to over water plants in this type of container. With very large plants, which are difficult to re-pot each year, it is helpful to put a dressing of fresh pot mix on top of the existing soil. With indoor plants always use a prepared potting mix rather than soil from the garden, except for plants such as ge'raniums and hoyas which will leaf at the expense of flowers if too rich a mixture is used. Having given your plants their fresh growing soil do not give supplementary feeding for the first month or so. Water as required and feed with a good pot plant food every two weeks during the growing season. Taper off feeding in the autumn, ceasing altogether in the winter which is the dormant season for most plants, and water sparingly to keep the

soil very slightly damp. Some plants, such as aspidastras and palms, resent being re-potted too often. Aspidastras need repotting about every two years and palms every four years. A dressing of potting mix on the top of the existing soil is all that is necessary. A few do's and dont's. Most plants like good light but not hot sun pouring through a window which will burn them, especially fine foliage plants.' Hoyas will flower better with some morning sun, and palms enjoy morning sun filtered through a net curtain. When watering, always drain the plant thoroughly before placing it back on its drainage saucer. If extra humidity is needed for plants such as maidenhair ferns, fill the saucer with fine gravel, water to the surface of the gravel and place the pot on top. This will supply only humidity. Water as usual, and keep dust removed from the leaves of broad-leafed plants by sponging gently with a cloth dipped in tepid water. Ferns and fine leafed plants can be sprayed occasionally in hot weather with clear water in a fine mist spray.