Over-watering

Gauteng is currently in the middle of its rain season. Usually, this would be a gardener’s dream, but the persistent wet weather affects drainage and most plants cannot tolerate having “wet feet”. Giving plants too much water is one of the biggest issues we see in landscapes today. Over-watering is not easy to diagnose as the signs of too much water often resemble the symptoms of too little water.

Below are four of the signs of distress your plants will show when standing in waterlogged soil for a long period:

  • Wilting leaves
    Roots transport water and oxygen from the soil to the plant. Well drained soil contains oxygen in the spaces between the soil particles. If the soil is saturated, there is less air available for the plant which will cause the leaves to wilt.
  • Leaves turn brown and wilt
    Leaves turn brown when the plant has too little and too much water. There is difference though. Too little water results in leaves that feel crispy, whilst too much water results in leaves that feel soft and limp.
  • Yellowing leaves
    Slow growth with deformed leaves is a symptom of overwatering. When there are yellowing leaves, or old leaves and new leaves falling off the plant at the same rate, then the plant is receiving too much water.
  • Warty growths, blisters & pests
    When the roots absorb more water than they can use, water pressure begins to build up in the cells of the leaves. This state is called oedema. The cells will eventually burst, killing them and forming blisters. When these blisters burst, tan, brown or white warty growths begin to form where the blisters originally were. This bursting of cells can also attract aphids and other sap-sucking pests which puts the plant under additional stress.

 

Pests attacking the same Buddleja as above

 

Gardening tips to avoid over-watering:

  • Switch off your irrigation system if the ground is wet, or have a rain sensor fitted so that the irrigation will automatically turn off when it’s raining
  • If the ground is water-logged, aerate the soil to increase the surface area to assist in increasing the rate of moisture loss
  • Add compost to improve the soil’s water-holding capacity
  • Mulch your soil to avoid compaction of the soil from heavy downpours