Potting up plug plants

They generally arrive with five to eight pairs of 'true' leaves, though this will vary between different plants and the plug size you've bought. They're especially useful if you've left it too late to sow or don't have the facilities to raise a lot of plants in the traditional way. They also require less heat and humidity than seeds, which is good news if you want to grow plants like petunias, nicotianas and French marigolds, which need a fair amount of warmth to germinate.

Most plugs are bought by mail order. Once they arrive, don't plant them straight out in the garden – they'll likely be eaten by slugs, snails and other pests. Unwrap them and check they're healthy and undamaged.

In our No Fuss video guide, above, Alan Titchmarsh explains how to ensure your plug plants grow and thrive. He demonstrates how to get plug plants out of the trays they're delivered in, and how to choose the right size pots and compost for your plug plants to grow in.

Find more tips about caring for your plug plants, below.

How to care for plug plants

Watering plug plants

As your plug plants grow, their water requirements will increase. Feel the compost with your finger on a regular basis and give it a good watering whenever it feels slightly dry. Ensure they have a regular supply of moisture to produce even growth, but don't allow them to sit in water for any prolonged period.

Looking out for pests on plug plants

Keep an eye out for greenfly. A small number isn't necessarily a problem and will be kept in check by birds, ladybirds, hoverflies and lacewings. If aphids reach pest proportions you can blast them away with a jet of water from the hose.

Maintain ventilation around your plug plants

Keep your plants well ventilated so they don't scorch in the sun. On really bright days, a sheet of newspaper or old net curtain draped over them will protect them. Horticultural fleece may exacerbate the problem, as it doesn't allow much in the way of air circulation.

Pinch out the tips of plug plants

Pinch out any shoots that grow tall and leggy, to encourage bushiness, although many bedding plants branch naturally and won't need such attention.

Harden off plug plants before planting out

Harden off your plug plants before you move them outside permanently. This simply means standing them outdoors during the day and bringing them back under cover at night. Ideally do this for a week or more to get them accustomed to lower temperatures. At the very least, make sure they've had plenty of fresh air. Water them just before planting, too.

Planting out plug plants

Plant plug plants in their final location at a spacing that allows them to grow and spread. Also take steps to protect them from slugs and snails, which will eat tender, young foliage, even when they've reached a good size.

Plug plants by size

• • Mini plugs – these measure 4-6cm from base to tip and are usually available early in the year, from mid-March. They need to be grown on for eight to 10 weeks before they're ready to be planted outside
  • Standard plugs – also called medium plugs or simply plugs, they're 6-8cm from base to tip. They're on sale from April onwards and should be ready to go out after six to eight weeks
  • Jumbo plugs – also called garden-ready plugs, these are the largest, at 8-12cm from base to tip. Available in May, they can be planted straight into pots or hanging baskets outdoors once there's no risk of frost