Contents

1. Introduction (The Benefits, Which Plants to Use This For & How It Works)
2. Step-By-Step Guide on Creating a Pebble Tray
3. 
   

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Introduction to a Pebble Tray

Also called a 'humidity tray', pebble trays are an easy, fool-proof way to create a pocket of humidity around your chosen houseplant. Humidity is important for tropical plants as it'll slow the rates of drying soil (thus reducing the risk of drought damage), increase overall growth rates and will also help with preventing stress from repotting. 

What are the Benefits of a Pebble Tray for a Houseplant & How Does It Work?

A pool of water that sits directly below the plant's pot will slowly evaporate over the next week or two, increasing the local humidity around the plant. It can increase the humidity by up to 10%, which can make a difference in terms of its growing conditions. 

Increased humidity will also reduce the plant's need for water, so you won't need to rehydrate its soil as often. This is a great hidden weapon for forgetful waterers or frequent holidaymakers.

When Shouldn't I Use a Pebble Tray?

• If the room temperature is below 18℃ (64℉). Low air temperatures and high humidity will increase the risk of root rot & plant death. It's best not to use either a pebble tray or humidifier for houseplants in cold rooms. 
• For certain houseplants, like Cacti and Succulents that prefer drier conditions in the air.
• If your houseplant is grown more than 3m (10ft)  from a windowsill. Low light levels and high humidity can cause soil mould and over-watering/root rot, so it's best not using these unless a grow-light is directly above this plant.

What Plants Will Benefit Most from Pebble Trays & Increase Humidity?

• Carnivorous Plants (Venus Fly Traps, Pitcher Plants, Sundews, etc).
• Tropical Plants like Alocasia, Anthurium, Ficus Monstera, Peace Lilies & Orchids.
• Cuttings (currently being rooted in a pot, in soil). You won't need a pebble tray for cuttings being rooted in water. 
• Ferns like Boston Ferns, Blue Star Ferns (Phlebodium), Staghorn Ferns (if grown in a pot, in soil) & Maidenhair Ferns (Adiantum)
• Streptocarpus (Cape Primroses)
• All houseplants (except Cacti & Succulents) grown in pots smaller than 10cm in diameter. Smaller houseplants in tiny pots are more likely to dry out and die from dehydration than larger plants, so installing a pebble tray is a great way to combat this. Small Cacti & Succulents, however, won't need the extra humidity from a pebble tray as they prefer drier air. 

Step-by-Step Instructions on Making a Pebble Tray for Houseplants

What You Need for a Pebble Tray:

• A shallow tray, saucer, or dish
• Pebbles, gravel, LECA, or decorative stones
• Water
• Your plant in its pot (with drainage holes)

1. Choose a tray

Pick a tray or saucer slightly wider than your plant pot. It should be deep enough to hold pebbles and a small amount of water but not so deep that the pot sits in water. THE HOUSEPLANT DOCTOR™ recommends a saucer that's around 8cm (3in) wider than its pot so that the standing water has space to evaporate around the foliage. 

2. Add your pebbles or stones

Fill the saucer to the top with a layer of pebbles, gravel, or LECA balls. Make sure your saucer is at least 3cm (1in) in depth or deeper as shallow trays will need refilling constantly. 

3. Add water

Pour water into the tray until it reaches about three-quarters up the saucer. Always ensure that the water-line is just below the tops of the stones or LECA to avoid the plant becoming waterlogged. 

4. Place the plant on top

Set your potted plant on top of the pebble layer. You can either place the plant's plastic pot on the saucer, or include a decorative pot, too. As long as the saucer is at least 8cm wider than its pot, all is okay!

Once the plant is seated on the stones, ensure that the pot's base is not touching the water line. If it is, pour some of the water away to create that gap. 

5. Maintain the tray

• Refill the water when it evaporates, ensuring it doesn't become fully dry. 
• Replace the water once a week (if evaporation is slow) to prevent stagnation or algae growth.
• An additional step is to rinse the stones from time to time (every two months) if algae grows on them. This in itself won't hurt the plant, but most people prefer not to see algae so it's your choice to remove it or not. 

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