A guide to re-potting.
Updated: Oct 26, 2020
Spring is the perfect time to re-pot your houseplants, just before the onset of their Summer growth period. Some plants can live happily in the plastic nursery pot in which it was purchased for 18 months up to 2 years, others will appreciate being potted on immediately and the rest fall somewhere in between.
The best way to check if your plant is root-bound is to upend it to see if roots are showing through the holes at the bottom. And if, when your plant is eased out of its pot, you can see roots spiralling in circles at the base, that's a sure sign that the plant is searching for more space, nutrients and water.
It's important to choose a pot just one or two sizes larger, as re-homing into too large a pot can be counterproductive - it can shock the plant, and any 'empty' compost sitting damp for long periods can encourage root rot. So if you've got a plant in a 10cm pot, go up to a 12 or a 13 (helpfully there are numbers printed on the bottom) as the plant should have just one or two 'fingers' of extra space all the way around. I try to re-pot a selection of my houseplants at the same time each Spring, so that I can utilise all the pots I already have. (Much like the phenomenon of Hermit Crabs swapping their shells at the beach!)
You'll need a trowel or kitchen spoon for the soil, and it's a good idea to lay down some newspaper if you don't have an outdoor space. Watering your plants a day or two before you plan to re-pot them is also good practice.
Step 1. Loosen the plant from its existing pot. If you've kept it in its plastic nursery pot this should be easy. Gently squeeze the pot all the way around to loosen the root system.
Step 2. Spread your fingers around the stems on the soil surface to support your plant as you upend the pot. You may have to cut the pot if it's especially compacted, but every pot saved can be used again to re-pot a smaller plant.
Step 3. Once your plant is free, tease out a couple of centimetres of the roots, discarding the old soil.
Step 4. Place an inch or two of fresh compost into your new pot and situate your plant so that it's at the right height. One or two centimetres below the rim of the new pot is ideal, any higher and you'll have difficulty watering without both water and soil spilling over the rim and making a mess. Back-fill the rest of the pot with new soil.
Step 5. Next, press around the plant to firm it in, but not so much that you'll compress delicate roots or compact the compost - air within the soil is just as important as moisture.
There should be enough fertiliser in the new compost to feed the plant for the next 2 months, so no additional feed should be necessary.
Step 6. Finally, water your plant in, top-dressing with a little more compost if the soil 'sinks' too much. Water well, until you can see it running out of the bottom of the pot, (this way you know you've properly saturated the soil) and shake off any excess before placing it into its decorative cache pot. You should be rewarded with fresh, vigorous growth within a matter of weeks.