Wetness Of Compost

If you look at last year's posts, you will see that I made a really big thing about watering. This is because, in my view, it is the crux of growing, the most important thing to master. It is also where almost all novices (and even some professionals) go wrong. Considering it is so critical and we mentioned it so much, it's strange that I never got around to defining some sort of standards which can easily be referred to for all occasions.

So I thought it about time I did just that, and indicate what I mean by a light, medium and heavy watering, both for propagating seeds and cuttings in compost, and for growing plants in pots.

COMPOST FOR SEEDS AND CUTTINGS

light watering
Mix water into compost thoroughly, squeezing constantly with fingers to ensure even distribution. After mixing, pick up a handful and squeeze quite hard. Water should be heard, and might just be visible at maximum pressure. However, water should not run out between the fingers, and should retract when grip released. Compost should form a ball which holds together upon release but which breaks up easily when poked. Hand should be left slightly damp but not wet.

This mix is ideal for taking cuttings and for use in a propagator.

medium Watering
Mix water with compost as before and clench a handful. This compost should release water through fingers when squeezed hard. But this release should stop when grip is released. Hand should be left wetted.

This is a very useful level of wetness and is ideal for many purposes when growing plants.

heavy watering
Compost is wetted and mixed until no more water can be added, then allowed to drain. It is then said to be at field capacity, an important factor in plant growth which we shall be discussing later on. Care should be taken not to add too much water, since drainage water will remove valuable nutrients (to avoid this, I catch drainage water and add back to compost as soon as possible).

WATERING POT PLANTS

light watering
Fill the space (usually about 1.25 cm (1/2 inch)) between compost surface and top of pot with water and allow to soak in. Watch that water does not run down side of compost, especially when it is dry. Dishing the surface helps avoid this. Tepid water also soaks in better than cold. A drop of eco-washing detergent can also be added as a wetting agent: this will help 'lubricate' the compost.

Use this level for winter watering, or any time plants are not in full growth.

medium watering
Two light waterings (i.e. about 2.5 cm (1 inch) of water). Compost must be allowed to drain.

This level is used when plants are in full growth but not in flower.

heavy watering
Soak pot either by immersion or by adding water, then allow to drain. This technique is useful if compost is becoming dry, since it ensures no dry spots are left. I water cyclamens and some geraniums (pelargoniums) this way. But all plants benefit from this technique occasionally, since it washes all old unused salts out of compost and makes way for a fresh start. It is essential that the pot is allowed to drain before putting back on a saucer, since we do not want the delicate root hairs immersed in water, especially with water sensitive plants like fuchsias.

This level of watering is usually only given when plants are flowering and in full growth.