Growing herbs at home to use in your kitchen is a simple and easy way to garden in a small space.
But remembering to water your plants is another thing entirely, and if you travel a lot, it makes it doubly complicated.
This self-watering planter features a reservoir in the base that keeps plants hydrated. The soil wicks moisture from the reservoir, which the roots of the plants then access.
This project is made using simple store-bought materials and can be tailored to the size required.
Tools and materials required for this project
- Plastic tub
- Timber crate
- Cordless drill
- 10mm drill bits
- 20mm PVC pipe
- Small plastic pots
- Geotextile fabric
- Premium potting mix
- Assorted herbs
- Icy-pole stick
- Wine cork
How to make a self-watering planter
1. Select the box
The planter is made using a simple plastic storage box, which is then housed inside a timber crate. Make sure the plastic box you select fits perfectly inside the timber crate. Select a box without any holes in the base, as this will form the reservoir and must be watertight.
2. Create the reservoir
Lay gravel over the base of the plastic box. Position two or three small pots amongst the gravel. These will act as ducts for moisture to wick through the soil. Lay geotextile fabric over the gravel and tuck it into the pots, then cut it to size.
3. Drill a drainage hole
Drill a 10mm hole in one end of the plastic box, about 50mm above the base. This will act as the overflow hole so the soil doesn’t become too waterlogged.
4. Make a depth gauge
Make a water depth gauge by cutting a piece of PVC pipe to size using a hacksaw, then inserting into the gravel. Drive an icy-pole stick into a wine cork, then insert it into the tube.
5. Fill with soil
Pour premium potting mix into the plastic tub to about 15 centimetres below the rim. It’s best to use a premium potting mix in small containers as it contains additional nutrients to keep plants healthy for longer.
6. Add the plants
Arrange herbs in their pots on top of the soil. One by one carefully remove the plants from the pots and position them in the soil, using a trowel to dig them in. Backfill with soil to the top of the rootball. Water in lightly.
Tip: It’s important to choose plants that require the same growing conditions, and thrive in moist soil. Adding flowers can add a pop of colour and attract beneficial pollinating insects.
How to water the plants
Carefully pour water into the gauge until it rises and stays up. This means that the water level is sufficient. If there is too much water in the reservoir, it will overflow through the drainage hole.
When the gauge falls, it means the plants need water. Plants can be watered through the gauge, or directly using a watering can. Depending on local conditions, it will be up to a week before the planter needs watering. You can also gauge when the plants need watering by feeling the soil. If it’s dry, the plants need water.