Watering – good garden practice

Plants need water. This might sound ridiculously obvious but have you asked yourself why?

For a start, water is the main constituent of the protoplasm*of plant cells – like humans, the bulk of a plant is made up of water. In many instances the turgidity (plumpness) of cells gives plants their shape which is why they wilt if water levels drop too far.

Moreover, plants ‘feed’ on nutrients that are carried in solution in water. This means there must be sufficient moisture in the soil for plants to maintain a fairly consistent through-flow of water and the nutrients dissolved in it.

Watering is about the roots of the plants. Also dreadfully obvious but it’s true in two ways. Firstly, it’s the roots that must have access to water to replace what the plant loses through transpiration from its leaves; more about that in the tips below.

Secondly, the origin of a plant (its ‘roots’) determines the way it has adapted to its environment. Plants from wet climates are structurally different to those found in deserts – it’s all about survival. Furthermore, plants are programmed to be sensitive to the seasons. This is also true of bulbs: in the Western Cape (home of a glorious multitude of exquisite bulbs) has a Mediterranean climate – winter rainfall – while the Highveld enjoys summer rain. It should be no surprise that Watsonias that thrive on the rocky slopes of Table Mountain will be miserable in a swampy, sub-tropical KZN garden. They will, however, be happy if they are planted in a sunny position where the drainage is good.

There are so many easy and sensible things that we as gardeners and lovers of our beautiful planet can do to water wisely. Here are some good gardening practices:

  • Start by choosing plants wisely and positioning them correctly. Try to match plants to the conditions in your garden so that you work with nature not against her. You’ll end up with less work to do, a much happier garden and a happier you too!
  • Find out whether plants love the sun or the shade or something in between, then plan, shop and plant accordingly.
  • Group plants according to their water requirements: some are thirstier than others (depending on their place of origin). If you group like-‘minded’ plants together, you can tweak your watering habits to suit plants’ specific needs – less waste and happier plants.
  • Work on improving the condition of your soil. You should systematically set about improving water retentiveness by adding organic matter (compost) to your beds regularly, especially if you soil is sandy or very high in clay content. This means, ideally, that you source an economical, bulky product that will open up the soil and provide a source of humus (decomposed organic matter) and perhaps some nutrients too. And because compost gradually breaks down in the soil, you have to keep repeating this process. I suggest you start a compost heap!
  • In general it is best to water a garden when the day begins to cool – it helps prevent evaporation and gives water the chance to soak into soil. However, bulbs and roses do best if watered in the early morning as they are susceptible to fungal disease and other problems associated with damp foliage. An early soaking gives leaves a chance to dry out properly before nightfall.
  • Water less frequently but more thoroughly – saturate areas rather than sprinkling superficially. This saves water in the long run and encourages plants to send roots down into deeper soil. This way plants can make the most of water resources.
  • Switch off irrigation systems on rainy days.
  • Sprinklers that need lower water pressure to function and send out big drops rather than fine mist are more efficient. Wind does not blow water away.
  • Here’s a simple one: check the soil before you water. If it’s already wet, don’t!
  • You can buy a soil probe to ascertain if watering is efficient. Otherwise put a rain gauge, or even a tub out when you water to see how effectively you are watering. Or dig a small hoe and check it out.
  • Mulch – it can reduce water needs by up to 50%! Mulch traps water in soil; keeps soil temperatures down and roots cooler; promotes good soil health and helps reduce weed germination.
  • Containers often need watering more frequently than plants in garden beds. Don’t forget to mulch in pots too.
  • Pull weeds: weeds steal water meant for your plants.

All the points above are applicable, in one way or another, to bulbs but there are some more specific requirements you should know about if you want to your garden bulbs to flourish:

  • Once you have planted your new season bulbs, never let the soil dry out completely. If you do, they will probably not flower.
  • Once a bulb has been exposed to water it will start growing. If you neglect to water it, it will abort its embryo blooms and perhaps even fail to produce leaves.
  • There is no point in superficially damping the surface of the soil if the water does not reach the roots of the bulbs. Therefore, in places where you have planted bulbs, soak the soil to 15 or 20cm every four to five days, or whenever the sub-soil dries out.
  • It is difficult to over-water bulbs BUT good drainage is essential for the well-being of most bulbs.

* pro·to·plasm n. The complex, semi fluid, translucent substance that constitutes the living matter of plant and animal cells and manifests the essential life functions of a cell.