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How to grow on plug plants


Filling your garden with colour can be an expensive business. Garden centres and nurseries are packed with attractive bedding plants in April and May, which are perfect to plant out for an almost instant show.

This convenience comes at a price. It’s certainly cheaper to grow your own from seed, but you’ll need to be skilled at germinating seeds, not to mention having the space and time. If you buy plug plants in spring, instead, you’ll find the growers have done the hard work – and there are still good savings to be made.

Give your plugs a little attention on arrival, unpacking them and standing them in water or misting until the compost is moist. Before potting on, leave them to settle in a warm, well-lit room for up to 24 hours.

How much care plugs require before being planted out varies by size. Mini plugs are the first to arrive, from early March, and these need the most care and time to grow on in trays or pots. Standard plugs come next and require potting and growing on for a month or so if you want filler plants for beds and containers. Garden-ready plugs can be planted out if it’s warm enough, but can also be grown on for a few weeks in a large pot, for sturdier roots.

How to do it


Mix together equal parts of multi-purpose compost and perlite for an open, free-draining compost. Then, gently remove each plug from its module, by pushing up from the bottom with a pencil.


Fill 7-8cm pots with compost, leaving a gap at the top to allow it to settle and make watering easier. Using a dibber or your finger, make a hole in the compost slightly bigger than the plug.


Holding each plug by its rootball, carefully tease out its delicate roots ad place it in the hole. Firm the compost gently around the plug to ensure the roots spread as the young plant grows.


When all the plugs have been planted, water with a fine rose. Keep on a bright windowsill or in the greenhouse for four to five weeks, potting on once for trailing plants, or twice for specimen plants.

Our tip

If there’s a chance of frost, pot these on rather than planting them straight outside.

A couple of weeks after potting on, both mini- and standard plugs will benefit from feeding. Compost contains some fertiliser, but you’ll get better growth by giving plants a balanced liquid feed, every 10 to 14 days.

Discuss this project

Talkback: How to grow on plug plants
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Mumshoovering 28/04/2014 at 19:20

It is April 28th. Is it possible to have plugs flowering by June 7th?
I planted a daffodil "50 Years" on the side of our ski turned out so well I've been asked to re-plant it for a grand celebration day on June 7th.
I though marigolds, violas, begonias......would antirrhinums, or stocks flower this year?
Any help or ideas would be very welcome.

nutcutlet 28/04/2014 at 23:01

I think getting plugs to flower in 5 or 6 weeks is over optimistic, maybe the odd one but not a display.

But go and see what the GC has, maybe something a bit bigger than plugs and a bit further forward. 

Verdun 28/04/2014 at 23:51

Getting near to the limit for plugs now I think if you want a good display this summer. Even stocks would be hard pressed to flower by June 7. 

I would go to a local nursery and buy plants at least in 9 cm pots.  Argyranthemums are available as decent size plants at the moment.  Remove the buds and feed amd water well and by early June they will flower again.  Lupins bought now will flower then too.  

Shazbat 15/05/2015 at 11:29

What am I doing wrong? I have bought some geranium and begonia plug plants by post,and I have potted them on and kept them in the greenhouse, but they are not coping well. The begonias especially have suffered - some have died back. I have added bonemeal to the soil.

How do you ensure that plug plants are taken care of and given the best chance to grow into larger healthy plants? Perhaps my fingers aren't green yet?

Thank you.


Verdun 15/05/2015 at 11:55

Maybe you overfed.  Bonemeal a big no for plugs.  There is enough food in the compost you pot them up in.  

Did you use compost or garden soil shazbat?

dont fuss them too much either.  Simply pot on, no extra feed, water well and let them be in a warm place indoors.

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