Solving Watering Problems in Your Greenhouse Garden

Cabbage growing amongst flowers.

Watering Problems?

Hand watering is fun for gardeners. If you are around to get the job done. But a wilted plant is a stressed plant and stressed plants get buggy. I would love to stay home all summer watering my
greenhouse at exactly the right minute but that’s just wishful thinking. The truth is, life gets in the way and instead of tending my tomatoes and pacifying my pak choi with hand watering I seem to travel just when my babies need me.


When the Greenhouse Garden heats up and the soil dries out faster than usual, I need more than a helpful husband or neighbour to get the watering job done. I need a system. So this year we are researching and testing irrigation systems for our two greenhouses. We will use these when we are away so I can still get the thrill of hand watering when I’m home.

Watering Systems to solve your problems


Used more commonly for pots and outside plants these nozzles work best when you have a row of similar plants or pots. The shrubblers are on a flexible line poked into a rigid tube. One nozzle is directed at each plant. The water flow for each nozzle can be adjusted to allow more flow as the plants grow or as temperatures rise. A timer can be added to make sure plants are watered in the morning when it does the most good.

Soaker Hose

Made from recycled rubber, these ½” (1 cm) wide lines are placed along the length of the row. Water seeps out into the soil and the hose can be looped back and forth to easily water-wide beds. This system works best where you won't even moisture throughout the bed, especially where planting designs change every year. Remember to set a timer to water in the early hours and to control the volume.

Self Watering Beds and Pots

Permaculture specialists build entire planting beds, called wicking beds, with sub-irrigated watering. This keeps the soil evenly moist and watered from a reservoir below. I use SIPs, a mini-version of wicking beds. SIPs (Sub Irrigation Pots) are lined up along the wall in my small 8’ x 12’ greenhouse and the growth so far is fantastic. I bought CAJA pots for both inside and outside my greenhouse and saw very similar-sized pots online at Lee Valley Tools. Fertilizer is added to the soil in advance and every 2-4 days water is added through a raised standpipe. In bad news, temperature affects how often pots need watering, so it might not be as hands-off as an irrigation system. In good news, it is easy to get help with watering because it is so simple. Just add water through the standpipe until moisture starts to drip out the overflow valve. I would say it is foolproof. Keeping your plants alive in your greenhouse when the weather gets hot is the definition of success in the greenhouse and with my systems in place, I am super organized this year! I will never again kill plants with kindness by overwatering just before I go away or depriving them when I’m gone. I am expecting record yields this summer.

Quick Tip: Some of the bottom leaves on my cucumbers and tomatoes are yellowing in my greenhouse and this means the plants need nitrogen. To fix it, I am sprinkling all my beds and pots with seed meal this week because seed meal, as well as blood meal, adds nitrogen quickly. I added a litre of Canola seed meal per 20-foot-long bed (approximately 60’ square).


Plants hanging from a basket in a greenhouse

Plants hanging from a basket in a greenhouse.

Plants in a self-watering bed
Plants in an Self-Watering bed