SELF WATERING POTS

I’ve been experimenting with some self watering pots for growing my veggies in this year - I’ve made some versions and bought some and all seem to be going well so far. 

Advantages of Self Watering Pots:

1. Watering is easier

• less frequent watering needed
• more flexibility about when I water
• reservoir acts as a safety net on days I am unable to water
• less water wasted

2. A constant water supply is provided to the plants, that will

• encourage maximum growth and yield
• avoid problems in the veggies that result from drying out (such as bitterness in lettuce or splitting and blossom end rot in tomatoes).
• increase heat resistance over our hot spring and summer.  (potted plants have a really hard time in the heat because as well as the plant on top, the sides of the pots and hence their soil and roots can bake as well.)

3. Water isn't left on plant leaves

• diseases such as powdery mildew less likely to develop
• leaves less likely to get burnt by water droplets heated by the sun

How does a self watering pot work?

Self watering planters work by providing a reservoir of water that is wicked up into the soil so that  the plants can draw on it.  The size of the reservoir allows for enough water to last the plant longer than regular watering can, and the supply is constant.  

They are not magic - they can’t entirely water themselves - they do need to have water added to the reservoir. The soil also needs to be top watered to start them off and to fertilise if you use methods that benefit the leaves as well (such as seaweed or fish fertilisers).  Care must be taken with fertilising to avoid the buildup of salts in the reservoir, because excess fertiliser will be fed back to the plant rather than draining away.

Diagram Copyright by Megan Michie

The key elements of a self watering pot:

• Space for plant, with drainage holes for excess water added from above to escape into the reservoir

• Reservoir to store the water

• Wick to provide a means for the water to move from the reservoir into the soil and roots of the plant by capillary action.

• Overflow outlet to prevent reservoir from overfilling and water logging the whole pot. The presence of an overflow outlet creates a layer of air in the reservoir above it and below the bottom of the soil to aerate the soil to maintain the air pockets needed in the potting mix for good root growth.

• Water inlet - to allow water to be added to the reservoir.

Over following posts I will describe some designs for self watering pots, how I made them and how they are working out.