How does a self watering raised bed planter work?

A self watering raised bed planter is a type of garden bed that allows plants to be watered automatically without manual watering. This system uses gravity and wicking materials to draw water up from a reservoir into the soil bed.

What are the benefits of a self watering raised bed?

There are several advantages to using a self watering raised bed planter:

• Convenience – The system waters plants automatically, saving time and effort.
• Consistency – Plants receive a constant supply of water as needed, avoiding under or over watering.
• Water efficiency – Less water is lost to runoff or evaporation compared to top watering.
• Healthier plants – Constant moisture promotes faster growth and higher yields.
• Less maintenance – No need to monitor soil moisture or manually water each day.
• Versatility – Works for vegetables, flowers, herbs, and other plants.

What are the main components of a self watering raised bed?

A self watering raised bed has several key components that work together to deliver water to the plants:

• Elevated soil bed – The raised bed lifts the planting mix above ground level and prevents it from becoming waterlogged.
• Reservoir – This is a water storage container situated below the soil bed that holds the supply of water.
• Wicking material – Absorbent materials like coconut coir rope draw water upward from the reservoir into the soil.
• Watering tube – Perforated tubing or piping runs through the planter to distribute water.
• Bottom barrier – Plastic lining prevents water loss through the bottom of the bed.
• Overflow – Excess water can drain away to prevent overfilling the reservoir.

How does the self watering system work?

The self watering mechanism relies on capillary action to move water from the reservoir into the growing medium. Here is an explanation of the process:

1. The reservoir at the base of the planter is filled with water.
2. Wicking materials bridge between the reservoir and the soil bed above.
3. Capillary action causes the water to be drawn up through the wicks.
4. The wicks slowly release water into the surrounding soil as it becomes dry.
5. Plants can absorb the moisture held in the soil bed as needed.
6. As the water is depleted, the wick continues pulling up more from the reservoir.
7. The watering tube also releases additional water into the planter bed.

This constant supply of water is delivered without any electricity or pumps. The self watering system provides a passive, low-tech way to irrigate the plants in the raised bed.

What materials are used to build a self watering raised bed?

A self watering raised bed planter box can be constructed from a variety of materials. The most common options include:

Material	Characteristics
Wood	Typically cedar, pine, or redwood. Durable, affordable, and easy to build with.
Plastic	Recycled plastic lumber or resin raised beds. Long lasting with fewer repairs needed.
Metal	Galvanized steel, aluminum, or powder coated steel last for years. Can feel hot in direct sunlight.
Concrete	Poured concrete or concrete block construction. Heavier and more permanent option.
Fabric	Polypropylene cloth raised beds. Lightweight and portable but less durable.

The reservoir at the base can be made from plastic, metal, or other watertight materials. The wicking system often uses nylon rope, absorbent fabric mats, or coconut coir. A drip irrigation tube may also be incorporated.

What are the steps for assembling a self watering raised bed?

Building a DIY self watering raised bed involves a sequence of construction steps:

1. Cut and join raised bed materials – Cut wood, plastic lumber, or other materials to the correct size and join into a square or rectangular frame shape.
2. Build the reservoir – Use a plastic tub, galvanized steel tank, or watertight liner to form the base reservoir that will hold water.
3. Add wicking system – Place coconut coir wicks, nylon ropes, or absorbent mats in the reservoir that extend up into the bed.
4. Install watering tubes – Insert perforated piping or tubing throughout the planter to distribute moisture (optional).
5. Line bottom – Add waterproof barrier layer over base reservoir to prevent leaks.
6. Attach bottom to sides – Secure the base waterproof liner around the bottom edges of the raised bed walls.
7. Add drainage – Drill overflow holes near top of reservoir walls to prevent overfilling.
8. Fill with soil – Shovel planting mix into the raised bed over the wicking system.
9. Plant plants – Add your vegetable plants, flowers, or other greens in the bed.
10. Fill reservoir – Pour water into the base reservoir to saturate wicks and start water flowing.

Follow these steps carefully to create a functional, leak-free self watering raised garden bed for your yard or patio.

What are some tips for using a self watering raised bed successfully?

Here are some useful tips to help ensure your self watering raised bed system works effectively:

• Use coarse planting mix – Soilless media with perlite, vermiculite, coco coir helps hold moisture but still drains well.
• Leave reservoir space – Don’t fill reservoir to the brim. Leave a few inches empty to allow for water displacement.
• Use gravel or filler – Adding pea gravel, polystyrene, or other filler takes up space in the reservoir for less water.
• Monitor overflow – Check that excess water can drain freely from the overflow to prevent waterlogging.
• Replenish reservoir – Refill with water as needed based on your climate and plant water demands.
• Maximize wick contact – Wicks should fit snugly from reservoir up into the bed to keep soil moist.
• Consider a float valve – Adding a float valve maintains ideal water level in the reservoir automatically.

A bit of trial and error when first setting up the system will help you understand how to customize it for optimum growing.

What can you grow in a self watering raised bed?

Some of the best plants for self watering planter beds include:

• Tomatoes – A thirsty vegetable crop that benefits from constant moisture.
• Lettuce – Shallow rooted greens require frequent watering that this system provides.
• Peppers – Keeping soil consistently moist produces higher yields.
• Herbs – Most herbs like steady water and grow well with this method.
• Flowers – Many flowering annuals love wet feet more than thirsty periods.
• Strawberries – Maintaining soil moisture without overwatering is ideal.
• Beans – Vining plants need a steady supply of water as they grow.
• Broccoli – Head forming vegetable that prefers constant moisture.

In general, plants that demand a lot of water and dislike drying out are best suited to self watering planter boxes. The system maintains optimal moisture levels without labor-intensive hand watering required.

What are some common problems with self watering raised beds?

While very effective when built properly, there are a few potential problems to be aware of:

• Reservoir leaking – Lining may develop cracks and seep water, proper construction prevents this.
• Wicks drying out – Interruptions in wicking action cause dry spots if not saturated.
• Salt buildup – Fertilizer salts accumulate over time and need flushing.
• Algae growth – Exposed water in reservoir can promote algae growth.
• Wicking too slow – Dry periods happen if water moves too slowly from reservoir.
• Plant overwatering – Some plants may receive too much moisture leading to root rot.
• Mechanical issues – Malfunctioning float valve, overflow, or irrigation line problems.

Being aware of these potential failure points allows you to design, operate, and monitor your self watering bed to avoid them.

Conclusion

Self watering raised bed planters provide a convenient, efficient way to water your garden beds or containers. The key is creating a well-designed system that leverages gravity, capillary action, and evaporation to move water into the soil automatically. With a properly constructed wood, plastic, or metal raised bed and reliable water reservoir, the system can keep plants watered with minimal maintenance required. Knowing how the self watering mechanism works allows you to troubleshoot any issues and grow thriving vegetables, herbs, and flowers.