Why is repotting so necessary?
Plants growing in pots from very small (50mm diameter) to very large (half wine barrels or planter boxes) have a finite quantity of potting mix around their roots.
Potting mixes are made from composted bark. The composting process doesn't stop when the potting mix is bagged for sale - it is a continuing process which results in the potting mix eventually breaking down completely.
The symptoms of a potting mix being past its useful life include:
- Water running straight through the pot and out the drain holes.
- Plants wilting quickly.
- Plants showing signs of yellowing and little or no growth.
How often should I repot?
The frequency of repotting will be influenced by the quality of the potting mix that:
- Was in the pot when you bought the plant, or;
- You used last time you repotted it.
Over time, the level of the potting mix in the pot will drop ('slump') because the potting mix has broken down to such an extent that it has washed out the drainage holes or has compacted to become a solid mass.
Top tip
We recommend repotting or topping up* at least every two years with a superior or premium potting mix to ensure your plants have the best growing conditions and nutrition you can provide.
* Large containers and barrels that are physically too large and heavy for a complete repot may be topped up with fresh mix every year or so, to bring the mix back to its original level and replenish the nutrients in older mix.
What happens if I don't repot?
If you don't repot when plants need it, you run the very real risk of plants becoming pot bound - they outgrow their existing pots. Their roots may completely fill pots, displacing the potting mix and depriving them of water and nutrients. Pot bound plants will struggle to survive.
Some plants are very vigorous and may outgrow their pots in just a few months. These fast growers may be moved into pots one or two sizes larger than you would normally use, to cater for their rapid growth and reduce the number of times you have to disturb their roots over a growing season (Spring to Autumn).
Top tip
After repotting, make sure to water plants thoroughly to 'settle' the potting mix, removing air pockets and ensuring it is thoroughly wet. To help plants overcome the trauma of being disturbed, add Scotts Osmocote® Pour+Feed All Plant Types to the water (30mL to a 9L bucket).
Tricks & advice for repotting your plant
