How to grow on plug plants

Do it:

Mar, Apr

Takes just:

15 minutes

At its best:

Jun, Jul, Aug, Sep

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.

You will need



Good quality compost



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.


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.

Discover more ideas and inspiration

Related content

How to take begonia leaf cuttings

How to grow summer bedding from seed

How to feed your plants

Related offers


Subscriber only content

Petunia 'Queen of Hearts'

Be one of the first to grow this brand new variety from Thompson & Morgan. Save £5 when you buy 10 plants for just £14.98, plus free p&p.

Unlock now


Seed sowing masterclass

Learn everything you need to know about seed sowing on David Hurrion's information-packed masterclass. Spaces are limited, so book early to avoid disappointment.

Use code: GW Masterclass

Order now