Most plants don’t like water-logged soil as the roots are susceptible to rot, fungus and bacteria, so it’s vital that you provide decent drainage.
You can keep your plants happy by using pots with drainage holes, or by adding a layer of rocks and gravel to the bottom of the planter. This directs water away from the roots of the plant.
You can also keep your plants healthy by adding a layer of horticultural charcoal to the pot or planter. This absorbs excess water from the roots of your plant and keeps the soil “sweet” by guarding against bacteria, fungus and rot. It also helps to eliminate odours, and is particularly effective in terrariums.
You can find horticultural charcoal at garden centres and nurseries.