Time to repot – or not?

As the growing season slides into autumn, plants growing in containers need some attention. It’s time to repot, refresh or refrain.

I doubt there’s anyone out there who doesn’t have at least one plant growing in a pot or other container, even if it’s just a single houseplant. A question that we are regularly asked at the Flower Power Gardening Club is about how, when, and why to repot these plants.

As our families get bigger and we’ve now got six children sharing the same bedroom, and there’s no room to move, we usually consider it’s time for moving on and getting something bigger to live in! And it’s exactly the same for our plants.

If they reach a size that their roots completely fill the pot and there’s little compost remaining for any new roots to grow into, they can start to give up the ghost. This is often seen by the leaves yellowing or dropping prematurely and a point-blank refusal to flower. Although the opposite can also be true; thinking that they’re about to die, some plants flower more profusely than ever before to produce lots of seeds (their “babies”) to produce new generations to ensure the survival of the species.

The lack of compost in the pot also makes watering trickier for you, as there’s nothing to hold on to the water, so plants regularly wilt unless you give enough water on a very regular basis to cater for their needs. This also means there are no nutrients for them to absorb either and so they will start to decline. 

Repot

Once plants become potbound or rootbound, and the container is full of roots, it’s time to repot and give the roots more space to grow in.

This is best done from mid-autumn to mid-spring, but can be done at other times. Ideally, don’t do it when a plant is in full flower nor in the height of summer, as the stress may be too much for them.

It’s best not to go from a small container to a massive one, but chose a planter slightly larger, even if this means you have to repeat the process every few years or so.

Of course, you’re going to need some fresh compost to add to the new pots.

Richard’s multi-purpose composts – Flower Power Premium Multi Purpose Compost and Flower Power Premium Peat-Free Compost – are perfect choices. While many experienced gardeners prefer peat-based composts over peat-free, as the UK government plans to ban peat use by home gardeners by 2024, we’ll all have to get used to using peat-free versions. 

For long-term plants you may want to mix multi-purpose compost with John Innes No3 Compost. This is often a better option for such plants and the extra weight it provides is a good idea for tall plants, which may otherwise keep blowing over in windy weather.

And, of course, lime-hating/acid-loving plants will need an ericaceous compost, such as Flower Power Ericaceous Compost.

To give plants you’re repotting an extra helping hand and a real boost to help recover from the trauma of moving home, add some Root Booster and/or Container Magic to the compost first.

Replace & renew

Those long-term shrubs and perennials growing in containers that don’t need repotting, and plants in huge pots that can’t go into even bigger ones, will thank you if you just zhoosh up their living quarters every year.

Either with a gloved hand or a hand fork, scrape away the top 2.5-5cm (1-2in) (exactly how much depends on the size of the container) of old compost and replace it with fresh. It’s also a good idea to mix some controlled-release fertiliser, such as Easy Feed, with the fresh compost.

Similar to when repotting, adding Root Booster and/or Container Magic to the compost will give the plants a lovely reviving tonic and make their aftercare easier.

With large plants in large containers, it’s also a good idea to completely remove the plant from its container (if you can lift it!), work over the whole rootball with a hand fork to remove any loose compost and dead roots and pop it back into the container with fresh compost.

Leave houseplants alone

Unless a plant has got too big for its home, there isn’t really any need to repot. In fact, repotting such plants can cause lots of problems, and this is especially true of houseplants. 

Repotting these when they don’t need it, can cause root rotting followed by the whole plant dying. Some people think that repotting poorly-looking houseplants is a good idea and will revive them, when, in fact, repotting will have the opposite effect and sound the final death knell for the plant. And flowering houseplants will always bloom more profusely if they’re slightly potbound.

Instead of repotting, give them a reviving pick-me-up with Plantsmith Fortifying Houseplant Tonic and Plantsmith Perfecting Houseplant Care Mist.

The best time to repot houseplants is from March to May, although at a stretch you can do it in June and July, but don’t try it at other times of year. And only move into the next size pot.

So, unless it needs it, because it is potbound, put that bag of compost away!