Whether you’re using metal or poly stone planters, following the right installation steps ensures your plants flourish while protecting your investment from moisture damage. In this guide, we’ll walk you through how to line your planter, add drainage and soil layers, plant effectively, and maintain your planters year-round for optimal performance.
How to Install and Maintain Outdoor Planters
1. Install the Liner
Why install a liner? It provides a layer between the soil and the planter walls preventing any excess moisture and or nutrients to leech through which over time will discolour the surface of the unit.
- Use either a perforated or non-perforated liner.
- Cut ample channels or drainage holes to allow excess water to escape freely into the base between slats.
- Fix the liner tightly to the inner edges, when filled the pressure of the contents will hold it in place
2. Add Drainage Material (Base layer):
- Fill roughly one-quarter to one-third of the planter’s volume with drainage material.
- Suitable options include hydroclay pebbles (we only offer trade size bags) or broken crock/ Terracotta pieces (garden centres can provide this for free in some cases).
- These materials provide air pockets that retain some water for drier months while allowing excess water to drain away in wet conditions.
We would consider this the best drainage material to use based on the manufacturers guidelines for their own products.
3. Add Soil Mix (Middle layer):
- Fill the next section (about one-third to half the planter) with a free-draining soil mix.
- Potting compost should be blended with additives such as perlite, vermiculite, coir, or charcoal. These additives improve aeration, prevent compaction, and protect roots from suffocation. We offer a pre-made potting soil from Jiffy that is ready to use and has perlite and coir mixed in for this purpose. Otherwise you can individually purchase large bags of each and mix it into your potting soil which can be more cost effective if you are planning to install multiple planters on your grounds.
The goal is to create a light, fluffy, open soil structure that encourages healthy root growth without it compacting the rooting structure over time.
4. Planting and Watering (Top layer):
- Place your plant(s) into the final layer of soil and water in thoroughly.
- Allow water to drain freely from the bottom to ensure the growing medium is fully saturated. This confirms your drainage system is working correctly, with excess water running off as intended.
- Top dress the soil and plant using decorative bark such as Eco Topper or Strulch mulch to preserve temperature of the soil and also moisture within the planter unit.
5. Winter Protection:
In the winter months, it’s a good idea to protect your planter and plants from frost and prolonged cold snaps. You can use a horticultural fleece or even repurpose old blankets or duvets to wrap around the planter for insulation. This is only a case of extreme weather drops in the UK which has occurred over the last 3-5 years with temperatures dropping to -5 degrees at night but a nice cosy +5-8 Degrees ℃ during the day.
Planters are most vulnerable where they are in constant contact with moisture.
6. Extend The Life of Your Planter
- Seal the material annually with a clear protective coating to create a water-resistant barrier using a wax based or stone sealer.
- Keep the planter raised never allow the feet to sit in standing water or wet soil, as moisture will penetrate from the base upwards.
- For hard surfaces (patios or stone), use rubber stoppers or spacers beneath the planter to avoid direct contact with the ground.
- For soil or grass installations, prepare a gravel bed as a foundation to prevent the planter from resting directly on damp earth.
These simple preventative steps will reduce water damage and significantly prolong the lifespan of your planters.
Sinclair Pro Series Hydroleca Pebbles
Sinclair™ Hydroleca's porous structure enhances drainage and aeration, preventing waterlogged roots and promoting healthy root development.
Jiffy Propagation Soil, Coir and Perlite
This premium seed starting medium is specifically formulated to provide optimal conditions for germination and root development.
Frost Protection Fleece 1.5m x 250m
This versatile horticultural fleece provides excellent protection against cold, frost, and other harmful weather conditions, Its lightweight and flexible nature make it easy to handle and manipulate.