Rain and other seasonal issues
There’s been a wee bit of rain lately, and many plants do not like wet feet, or excess water around the root zone.
Most semi-tropic plants hate wet feet, which accentuates the effect of lower winter temperatures, and more often than not they will die.
There are plants too that need a reasonable amount of oxygen in their root zone, and when saturated with water the oxygen goes and rots set in. Citrus trees are among these and will suffer and even die during wet times if their root systems are sitting in water for too long.
I was sent a photo this week of citrus tree leaves that were curling back on themselves, and asked about the problem.
The tree is one of a number in a grove planted on reasonably well-drained flat land in a sunny situation with shelter from the wind.
Affected by curling leaves and leaf drop, this tree was at one end of the grove. However, nearby trees were starting to show signs of the same problem while trees further away were apparently good as gold. The reason? The trees had been mulched. Mulches are a great way to retain soil moisture levels during dry times but this can be a big disadvantage during wet times.
Under the soggy mulch, the soil can’t breathe, moisture is trapped and then the roots rot.
A similar problem affected expensive ornamentals another gardener had planted on a slope.
She had placed old carpets down as a mulch to conserve summer moisture on the slope. Then winter comes. Rain falls, the ground gets soaked, water can’t evaporate because of the carpet, roots rot, expensive ornamentals die.
At a previous property of mine, parts of the back yard could remain under water for weeks.
To solve the problem caused by heavy clay soil and no drainage, I planted a twisted willow in the far corner to soak up water.
A few cabbage trees followed and as they matured other hardy plants were able to survive.
I also laid a length of Nova pipe which drained into a sump hole using a submersible pump to suck up water into the storm water.
Even then, ponding still took place, but I was able to grow citrus trees in containers partly buried in the ground.
Large holes were drilled into the sides and base so the roots could penetrate out into the surrounding soil, but most of the roots were in compost above the water level.
The result was excellent citrus trees that were happy in the middle of a lake of water.
If you have citrus or other plants where the leaves are curling and dropping then likely they are in water
soaked soil and their roots are rotting.
It could be that the trees have been there for years and no problems in the past, but things can change.
New concrete paths and footings even on a neighbouring property can alter how water drains.
More rainfall than normal soaking the soil for longer periods does not help.
With climate changes, areas prone to heavier rainfalls will need to look at long-term solutions such as underground drainage systems and soak holes. If your citrus (or other plants) are suffering from wet feet, firstly ensure that any mulch is removed.
Next, just outside of the drip line dig a trench about one-and-a-half spade blades in depth and remove the soil from the area. It is an old method that causes the water from the saturated soil to move into the trench where it will evaporate more quickly through sun and wind.
Next spray the foliage with Perkfection Supa at full strength, and a month later at the lesser rate. Continue for another 3-4 months.
This will help the tree overcome the root rot problems if it has not gone beyond the point of no return.
For those who have had their properties flooded, there will likely be a lot of river silt about.
River silt will enhance the soil as it is rich in minerals and nutrients.
An example is the annual flooding of the Nile which enriches cropping areas.
As for sewage contamination, there is no need to pull out crops.
Sewage is great manure; the only caution is to wash produce well after harvesting, to wear latex gloves when working in the gardens and to
wash well afterwards.
Raindrops on lemons are fine at the top end of the tree, but underneath, wet feet can cause curling leaves, leaf drop and eventually the tree’s demise.