What's wrong with my pot plant?
No modern garden is considered complete without a few potted plants decorating outdoor courtyards and patios. But unhappy container plants quickly become garden eyesores, which is why it’s important to find out what’s causing the problem. This can take a bit of detective work, but here’s a checklist of some of the most common causes:
- Has the plant been fed? Fertilisers don’t last as long in potting mix as they do in the soil, because the mix itself tends to gobble up some of the nitrogen in the plant food. It’s easy, though, to burn confined roots with salty bagged fertilisers so, for pots, it’s always safer to use something organic like Dynamic Lifter pellets or slow release Acticote.
- Is the potting mix getting old? After a few years, potting mixes tend to lose their quality and begin to break down. This can cause what’s termed ‘slumping’ – when the mix sinks right down in the container. If a plant is likely to be in a container for years, use a top quality potting mix (something like Yates Professional). The best mixes always carry the red StandardsMark ticks on the bag. And it’s good practice to repot and, thereby, renew the potting mix every three or four years.
- Has the mix become water repellent? Another problem that can occur as potting mixes age is that they tend to become water repellent. Water runs down the sides of the mix rather than seeping into the root area. Renewing the mix can, of course, solve this problem but it’s also important to remember to use soil wetters on the
mix. These break the surface tension and encourage easy water penetration. Yates Waterwise Soil Saturator comes in a liquid concentrate that can be applied over the top of the mix.
- Is the drainage blocked? Many pots have only one drainage hole and, if the pot’s sitting on the ground, it’s only too easy for the roots to grow through to the soil. Here they’ll gradually expand and eventually block the hole – and the drainage. You can prevent this happening by choosing pots (like Yates Tuscans) that have plenty of drainage holes, or by sitting the base of the pot above ground level on pot feet or paving bricks.
- Are the roots being eaten? Curl grubs are the larvae of scarab beetles. These ‘C’-shaped grubs develop underground and live off roots, before emerging as adult beetles. If a plant that’s previously seemed in robust health suddenly starts
to decline, it’s worth checking the root area. Dig around and physically remove any grubs. If the problem persists, pot into fresh potting mix.
This area is for general comments from members of the public. Some questions or comments may not receive a reply from Yates. For specific gardening advice visit Ask an expert Alternatively you may wish to contact us.