When is the best time to repot plants? Gardening experts explain why getting it right matters
Are your plants outgrowing their homes? Here's when you should size up their pots and why getting the timing right is important
While it's great to watch your plants thrive so much that they start to outgrow their pots, it does mean you need to think about rehoming them. Unfortunately, it means more than simply sizing up the pot.
If you know how to repot your houseplants successfully, you'll know it's not always straightforward. And although there are some similarities, like the signs of knowing when to repot your houseplants, when you're upscaling your garden plants' pots, there are a few more conditions you'll need to keep in mind. The first one is when to do the repotting.
You might be thinking the best time to repot a plant is simply when it grows too big, but with outdoor weather conditions and nutrients to think about, there's a little more complexity to it. Luckily, the garden experts are here to explain when you should do it and why.
When is the best time to repot plants?
If you've noticed your patio container plants thriving and spilling out of their pots, you might be wondering if it's time to upgrade them.
"You should repot once the plant is actively growing so that it can recover properly from being disturbed," explains Dr Russell Sharp, Founder of Eutrema. "Most plants start picking up again in spring as the days get longer, and repotting at that point means the roots can still have months of stronger growth ahead and can establish into the fresh compost before winter."
"If the plant's growing well and the roots still have space, then I'd avoid repotting. It always causes disruption, so there should be a reason for doing it. If a plant genuinely needs more room, doing it during active growth gives it the best chance of settling in without a long period of stress," he adds.
So don't make an autumn garden mistake by repotting your plants too late in the year when they're starting to enter a more dormant period.
What months are best to repot plants?
If you're looking to sort your garden out and move your potted plants into larger-sized pots, there are a few months in the year that you'll want to wait for.
"March, April and May are the best months for most plants when it's getting lighter, and temperatures are becoming more stable," says Dr Russell.
"During this time, plants are moving into their strongest period of growth, and that makes recovery much quicker than it would be in winter when growth is slower and wet compost can sit around the roots for longer," he continues.
Even when you protect your plants from heavy rain during the winter months, the soil retains moisture for much longer, which poses its own risk.
"June can also be a perfectly good time for vigorous plants. I’d only repot in late autumn or winter if there’s a clear problem that can’t wait, such as root rot or compost that has broken down badly," points out Dr Russell.
Dr Russell is an innovator, best known for developing the range of plant care products offered by his company, Eutrema.
What are the biggest mistakes when repotting?
It might surprise you, but there are a fair few container gardening mistakes, and repotting comes with several of its own.
Horticulture expert and Commercial Director at LBS Horticulture, Richard Barker, has shared the most common mistakes gardeners make when repotting their plants...
- Wrong pot size: "Repotting into a pot that is too large can harm plants," begins Richard. "The excessive amount of soil can hold too much water, increasing the risk of root rot as it takes longer to dry out. Ideally, the new pot should only be one to two inches larger," he finishes.
- Lack of drainage: When repotting into a decorative container, it's important to check for sufficient drainage. "A pot that lacks drainage holes can mean water pools at the bottom of the pot, suffocating plant roots and increasing the risk of fungal diseases or rot," explains Richard. "If using a decorative pot, you should either drill drainage holes into the pot or use a pot that has drainage holes and can be placed inside of the decorative pot," he adds.
- Wrong soil mix: You'll need to check what type of soil mix your plant requires; the same bag of soil or compost won't suit repotting every type of plant. Richard also points out that using soil that is too heavy can compact and starve plant roots of oxygen, so try to match the potting medium to the plant, mixing in amendments like perlite or orchid bark if needed.
- Handling roots roughly: Richard says, "When repotting, you should avoid aggressively shaking soil from the roots, trimming roots back too much or packing new soil into the pot too tightly." He explains that major root disturbances can cause transplant shock, and tightly compact soil can stop oxygen from reaching the roots. So, he suggests, "After removing a plant from its pot, gently tease soil and tangled roots, aiming to keep some of the old soil around the root ball. Do not pat down the new soil too much, as this stops it from being loose and airy."
With 4 years in the industry, Richard is a gardening expert at LBS Horticulture. He is keen to share his knowledge with both experienced and beginner gardeners, and prides himself on keeping up to date with the latest horticultural trends.
Is it best to repot plants when the soil is wet or dry?
While it might make more sense to repot your plants when they're dry and compact, doing this can cause unnecessary stress.
"Ideally, you should repot plants when their existing soil is moist, not dry or soaking wet. The slightly damp soil helps to cushion the plant's roots so that they do not dry out or break during repotting, and it can make cleaning up afterwards easier," explains Richard.
"Moist soil also helps to keep the root ball of the plant intact, as soil that is too dry can cause it to crumble. For the best results, water plants thoroughly a day or two before repotting," he continues.
Watering your garden plants properly a couple of days prior will mean the soil is moist enough but not too wet and messy.
Having your gardening tool essentials at the ready will make this whole process a lot easier, and if you want to avoid a mess, putting a sheet of plastic down where you're working can make all the difference.
