How to Install a Container Irrigation Kit

This step-by-step guide covers how to install container irrigation kits, which are designed specifically for trees planted into pots or containers. You can watch a video version of this guide below.

Installed at the time of planting, container irrigation kits help your tree to receive only the correct amount of water, so you don’t have to worry as much about over- or under-watering.

For trees being planted in the ground, you will need to install a regular tree irrigation kit. Learn more by reading our other guide on How to Install a Tree Irrigation Kit.

Equipment List

• Container irrigation kit
• Tree suited for container growing
• Suitable container
• Soil-based planting compost
• Trowel
• Watering can 
• Rootgrow (optional but recommended)

Step 1: Choose a tree suited for container growing

Some trees are better suited than others for growing in pots. Dwarf Cherry Blossom trees, small Japanese Maples, compact Conifers, weeping Crab Apple trees, patio fruit trees, and Magnolia shrubs are particularly good choices. Visit the Trees to Grow in Pots section for a full list of our recommendations.

Step 2: Choose a suitable pot and the correct size container irrigation kit

We offer two sizes of container irrigation kit – a medium one for smaller trees, and a large one for taller trees. For the medium size, your pot needs to be at least 50cm tall, and for the large size, your pot needs to be at least 65cm tall. The base of your pot should always be at least 24cm wide, regardless of which size irrigation kit you go for.

Your pot should be large enough to allow the tree’s roots to develop. We recommend choosing a pot that is about twice as wide and twice as deep as the tree’s current root mass. A square-shaped pot is ideal as it encourages the roots to grow outwards from the root mass, rather than wrapping around the pot in a circle.

Check your pot will provide adequate drainage for your tree and if not, you may need to add some additional drainage holes to the bottom.

Step 3: Assemble the container irrigation kit

Your container irrigation kit comes in six parts – the reservoir, reservoir lid, capillary leg, filler pipe, filler pipe cap, and the float.

Reservoir

Reservoir lid

Capillary leg

Filler pipe

Filler pipe cap

Float

Take your capillary leg and fill it to the top with some of your planting compost, without compacting it too much. Slot the filled capillary leg into the central hole of the reservoir lid, then secure the lid onto the reservoir. Insert your filler pipe into the side hole on the reservoir lid, pushing it right down so it’s touching the base of the reservoir. Pop your float into the filler pipe, polystyrene end down. Then, attach your filler pipe cap onto the end of the filler pipe.

Step 4: Add crocks and a layer of compost to your pot

To aid drainage, add a layer of crocks or large stones to the pot before adding compost. Make sure they’re not acting like a cork so water can’t drain away.

Then add a layer of your planting compost, at least 1 inch deep.

Step 5: Insert your container irrigation kit

Insert your container irrigation kit on top of the first layer of compost. Make sure it’s level and the filler pipe cap will sit flush with or just slightly above the rim of the pot. Add some more compost to your initial layer if required.

Step 6: Add more compost and apply Rootgrow

Next, add more planting compost, covering the reservoir entirely. You’ll need about 5cm of compost between the top of the reservoir, and the bottom of the tree’s root mass. Then, we recommend sprinkling some Rootgrow at this stage to help the tree to grow strong and healthy roots.

Step 7: Place your tree and backfill

Remove the tree from its production pot and carefully tease out the roots, taking care not to break them. Then, place the tree into the pot. Make sure it is level and that the top of the root mass is sitting just below the rim of the pot. If you have a single stem tree, check the trunk looks vertical from all orientations.

Backfill around the root mass and filler pipe with your compost. Pushing the compost firm helps to remove any air pockets. Take care not to bank the soil up over the collar or graft union of the tree, as this can cause rotting.

Trees planted into containers don’t require a stake or tie, but if it comes with a cane, you should leave this attached for around a year or so after planting to give it some extra support.

Step 8: Insert water via the filler pipe cap, and water the surface of the soil with a watering can

Insert water into your filler pipe, until the plastic top of the float rises level with the filler pipe cap. Then, water the surface of the soil using a watering can.

When your tree needs water, it uses capillary action to draw the water through its soil from the reservoir. When it doesn’t need water, the water remains inside the reservoir, meaning your tree is never over or under-watered.

Step 9: After planting

Top up the water level periodically so it doesn’t run out and make sure to continue surface watering your tree as required, particularly in hot or dry weather. Also keep the pot free of other competing weeds and plants.