What are Sub Irrigated Planter Inserts and Modules


Spring signals a new beginning and a new growing season. This is especially true for the flowers, grasses and greenery that we plant each spring in boxes, containers, planters; pots and receptacles. Each year, we add soil amendments to the soil left from the previous year and add new plants to the planters. And in a few weeks, we hope for lush greenness and stunning brilliant colors to create a warm welcome and a respite from the dullness of asphalt pavement.

Unfortunately, one of never ending challenges is how to keep the plants watered especially when the plants require watering on a daily basis. In a business improvement district, the chore may be the responsibility of each individual store or business owner. If you’re lucky, the job may be the responsibility of a dedicated staff member or the chore may be contracted to a watering service.

Do yourself a favor this year and take a look at adding sub irrigated planter inserts or modules to your main street, business or retail district. A sub irrigated planter insert or module consist of hollow airtight reservoir, a moisture sensor with a porous tip, a water source and a fill hole with stopper or plug.

The reservoir is filled full through the hole at the top of the reservoir. A stopper is placed in the hole, creating an airtight seal. Water flows into the soil through small holes at the bottom of each reservoir (the water source). Thanks to the capillary action of the soil, water wicks its way up until it reaches the moisture sensor, planted at a level 1/3 to ½ way down the container. When the water reaches that level, the white tip of the sensor absorbs waters and closes like a valve. It prevents air from passing through the tubes, and a vacuum is created above the reservoir, keeping water from flowing into the soil.

As the plants and flowers use the moisture and the soil starts to dry, the sensor tip dries and allows air to pass through the tube. The vacuum above the water is broken, and water can flow to the soil. The process forms a cycle, interrupted only by the removal of the stopper and the filling of the reservoir.

The overflow drain (where present) allows excess water (typically rainwater) to escape without disrupting the cycle.

There are two types of sub irrigated planter devices – Inserts and modules. Inserts form a self-contained pot with the water reservoir in the walls. Modules are reservoirs connected with flexible tubing, directly planted in the pot. The inserts are made to accommodate specific shapes and sizes. Modules are made in different shapes, sizes and heights and can be combined into a variety of configuration to fit almost any type of container.

Here’s a video of how sub irrigation planters work.

So before you add plants to your flower boxes, containers, planters; pots and receptacles, take a look at sub irrigated planter inserts and modules. They’ll eliminate the need for daily watering and will make sure – if the water reservoir is filled on a regular basis – that you’ll get the lush greenness and the stunning brilliant colors of your desire.

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