Gardening with La Nina

I have always designed my gardens to be drought tolerant by selecting plants that cope with drier conditions. This is the condition we deal within this area, most of the time. Many of these plants however do not cope well with constantly wet soil. The well above average rainfall we have received in recent months has caused many of these established otherwise hardy plants to be negatively affected.

If your garden is totally submerged in water there is not a lot you can do in the short term to save plants especially if the water submersion is caused by a large natural water course. Much like long term drought conditions some plants will survive if they get to dry out soon enough whilst others will succumb to the conditions.

If any lesson is to be learnt from these three La Nina events it would be to ensure the drainage in your garden beds is optimized prior to planting out. It is hard to fix drainage once the plants are in and growing.  Here are some things to look out for in your garden and measures to take to help your plants survive La Nina.  

Why do plants not survive water logged soils?

When the soil is so saturated there is no room for oxygen within the soil therefore the plant roots don’t have access to oxygen which causes them to literally drown. Some plant roots have adaptations to allow them to survive inundated soils.

Signs of plants stressed from water logging
-Outer growth looks wilted even though soil is moist

-General yellow or discoloration of leaves

-Dieback in patches or tips

-Fungal diseases such as rust obvious on foliage

-Flowers don’t open just rot on the plant and fall off.

– Reduced leaf size

Measures to help you deal with water logged soil

Short term tips
-Try not to walk in your garden beds when the soils are sodden as your foot steps will cause compaction in the soil. This compaction can cause long term damage to your beds or lawn areas.  Wait until your soil has dried out to do any major work within your garden beds and lawn areas. 

-If plants are young and or not established lift out of soil relocate to a dryer area or pot up into pots

-Try to aerate the soil around their root bases by using a garden fork.

-Carve out some water channels for water to flow away from the roots of the plant to a lower level.

-Gently push a shovel underneath the central root ball. Slowly and only slightly lever the plant upwards – this only needs to be a few centimetres. This is only to be done ever so carefully but it might be enough to lift the bulk of the roots up and create some air pockets around them.   Do not lift totally out of the ground as you will damage roots.

-If it’s a plant that will cope with transplant – lift and relocate.

Long term tips
-Watch the drainage patterns in your garden during these times of heavy rain. Identify any key areas where pooling water could cause issues for your plants and any structures.

-Redirect surface water flow away from garden beds with pit drains, underground pipe lines, dish drains, swales and contour banks wherever possible. If these are installed prior to planting some can become features within themselves.

-Select plants species that can cope with some water logging in these drainage areas.  

-Ensure there are no bare soil earth areas within the garden- plant coverage including lawns will help slow runoff and prevent erosion

– Ensure all garden areas are mulched. Mulch will help prevent the topsoil from washing away.