Get the best from your plug plants

Hannah Jolliffe / 21 March 2016 ( 24 September 2020 )

Buying plug plants online is a great gardening short-cut as it takes away some of the troubles of growing from seed. So how do you treat your plugs with care and ensure they thrive? Follow our guideā€¦



What are plug plants?

Plug plants are also known as starter plants. These are young plants with independent root systems and they come in a variety of sizes, with the price generally increasing as the plants get bigger.

What are small plug plants?

The smallest plug plants often measure less than 8cm and are sold at astonishingly good prices and are easily delivered by post. Small plugs do require some growing on before they can be planted out as their small size makes them delicate. They should ideally go into a greenhouse, conservatory or light windowsill when you get them home. They're ideal for people who do not want to bother with planting their own seeds but want to get a lot of bedding plants at a very good rate (often less than 10p a plug!) 

What are jumbo plugs?

Jumbo plugs are bigger plug plants – also sold as ready plants. They are offered by many garden centres and online retailers. These are larger plugs that can be planted straight into hanging baskets or containers, but these usually need hardening off first, and if you're planning on putting them in the ground it's a good idea to repot them into larger pots to let them get a bit bigger. They work out slightly more expensive than the smaller plugs but are easier to grow and ideal for anyone wanting to fill hanging baskets or containers.

What are mega plants?

Mega plants are large garden ready plants that are suitable for planting straight into the ground. For this reason they do work out more pricey than plug plants, but they're a good way to fill borders when you want a good result quite quickly and are on a par with buying from a bricks and mortar garden centre.

Looking after your plug plants

It's important to treat your starter plants and plugs with TLC to give them the best chance of growing into large, strong plants. Some of your plants might have yellowing on the leaves - this a consequence of shipping and not a big issue.

When the plugs first arrive 

When you first get your small plug plants keep them indoors for 24 hours. Make sure they're in a light, draught-free area. If the compost is dry spray them with a little water (not too much - they should be moist but not wet) and store them where there is some airflow between the plants to prevent rotting. Make sure they can drain and are not sitting in water.

When your jumbo and mega plants first arrive

If you've ordered larger plugs they will need to be stored in a light, draught-free area for the first 24 hours. Light press down any compost that has become lose in transit. If the compost is dry stand them in a shallow dish of water, or spray the compost with water. Make sure the plants have some air flow between them to avoid leaves rotting.

Growing on your plug plants

Before repotting your plants water them about two hours in advance. Use good potting compost – it is specifically formulated to provide the best growing conditions needed for potting up young plants.

  • Fill a small pot and make a hole the same size as the starter plant.
  • Be careful when removing the plant - with small plants gently pinch the bottom and push it up from the bottom – use a pencil if it won’t budge, or a teaspoon for slightly larger plants.
  • Always try to avoid holding the plant by its the stem when transferring the plant - hold by its root ball and carefully tease out the roots before placing it in the hole.
  • Water once transplanted - sit the pots in a tray of water for 10 minutes and allow any excess water to drain away. Once they have been watered do not water them again until the compost is almost dry or the plant has started wilting.

Now you need to provide the best balance of water and light that you can. Keep them in a cool, well-lit area - don’t let them dry out completely, but remember that overwatering can also be fatal. Fertilise after about three weeks.

Hardening off and planting out

Hardening your plug plants off simply means that you are preparing them to be planted in outside temperatures. You can do this once the risk of frost has passed and your plants are a reasonable size.

Take your pots outside to a sheltered spot every day for two weeks, bringing them inside each night, before planting out into their final destination.

Top tips on ordering plugs online

If you shop smartly, ordering plugs online can be a great way to buy your starter plants. Follow our basic advice to get the best from your online plugs:

  • Look for a quality policy – this means that if you are unhappy with the standard of your plugs you can return them with no quibbles.
  • Check for delivery dates – if the plugs arrive when you’re away and end up with a neighbour or in the local sorting office they are likely to dry out and die. “The only problems I have had is when plants arrive and I am away. Young plants need water and not to get too cold,” says Zoe, a keen gardener.
  • If you know you will be out for the day, make sure you have a secure spot for deliveries to be left, out of direct sun.
  • “Always unpack, check and pot-on plants as soon as you can,” advises gardener Stephen Hackett from The Constant Gardener.
  • Plan what you need and don’t be tempted to buy plugs that are out of season.

Find out about the benefits of buying plants online

Give your garden a makeover and save money at the same time with a special Thompson and Morgan offer of 10% off.

The opinions expressed are those of the author and are not held by Saga unless specifically stated.

The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.