Make Self Watering Planters. Easy Wicking Containers for the Greenhouse

Water. That's what plants in the greenhouse need. In northern climes, you need your crops growing all the time. Daylight hours are long but the growing season is short.  I top off the water supply to plants in my greenhouse by adding home made self watering systems to my  potted tomato and pepper plants. They get a constant source of water, so they can keep growing at will.


This is easier than you think! The wicking system saves water, keeps the plants growing and happy, and saves time. Plant roots grow throughout the entire planter, not just towards the bottom, so bigger plants can do well in smaller containers. 


The basic idea is that you have a separate reservoir of water where  'wicks'  draw water into the soil where the potted plant is growing.  

The blue pails in the picture above show an easy self-watering system . These old pails are about the same size,  and the light blue pail stacks perfectly into the dark one, with a 4 inch gap at the bottom and top between the 2 pails. In this case, the 'reservoir' of water is in the bottom pail.  I drilled 12 drainage holes in the bottom of the top pail (light blue) and dropped  4 cotton 'wicks' (from an inexpensive mop refill) down from 4 of these holes, to touch the bottom of the dark blue pail, when they are stacked. You can use other thick ropes for 'wicks',  just make sure they draw water up.


I drilled a bigger hole in the side of the bottom pail about an inch under the base of where the top pail would sit, leaving a 3 inch 'reservoir' for water in the bottom pail. This side hole is for overflow drainage of the water reservoir- so there is always a gap of air between the water reservoir and the bottom of the upper pail.  Knot the wicks at the inside base of the top pail and draw them an inch or two up into the dirt in the top pail, so the wicked water is dispersed in the soil. Fill the top pail with light soil (not potting soil but potting mix- this seems to be important for absorption) and plant your pepper, tomato or plants of choice.  Water from above directly on the soil, and/or below-  into the hole in the side of the bottom pail. Make sure there is always water in the reservoir and once in a while, flush it out by filling through the bottom drainage hole to overflow. 

The reservoir doesn't have to be under the planted pot - it can be beside it, or even inside it. Experiment! Self watering window boxes, self watering hanging baskets, this is an adaptable watering system. I use plastic containers rated as safe for food to plant in.

wicks are from a cotton mop