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Pot on your plants for more flowers and veg

Follow Which?'s expert advice to get the most from your garden

Garden centres and supermarkets are now selling packs of tiny plug plants. They’re a great way of filling your borders and veg patch cheaply without sowing seeds. 

Plug plants are often only a few centimetres tall and have a delicate root system. As a result, they need a compost that will give them all the nutrients they need to grow, but won’t let the plants get too wet by holding too much water.

For the best compost for this job, look at our Best Buy composts for raising young plants.

How to pot on plug plants

If you have bought your plug plants in trays, they will be rooted in either a little compost or agar, a jelly-like growing medium. In either event, make sure they are well-watered before you try to remove them.

While you’re waiting for your plants to soak up the water, prepare your pots or trays. When Which? Gardening tested the best containers for young plants, we found that module trays were the easiest to use and disturbed the roots least when we potted them on.

Module trays have compartments, like mini-pots, held together in a grid. Heap your Best Buy compost onto the tray and gently shake it so the compost falls into the modules. Make sure the compost a level with the top of the tray, but don’t firm it down. Use a dibber or the end of a pencil to make a small hole in each module that’s a little larger than each plug plant.

Plug plants need careful handling to avoid damaging them. Gently squeeze the tray and pull out the plug plant, holding the leaves. Pop each one into a module and gently firm it in, using a dibber or pencil. Be careful not to touch the delicate stem or roots, always holding by a leaf. Water the tray, using a watering can with a fine rose, or put the module tray into a larger tray without holes and pour water into this so the compost can draw up the water.

For tips on how to pot on seedlings and other jobs for April, see our Grow Your Own video.

Looking after plug plants

Keep your trays in an area that has plenty of light. Tender veg and flowers need to be kept in a heated greenhouse or in the house on a windowsill, but hardy plants cope well in a cold greenhouse or coldframe. For more on this, see our guide to protecting plants from frost.

Young plants shouldn’t need feeding for the first few weeks. Most composts contain enough feed to keep plants growing well for four to six weeks. After this time your plants will probably be ready to be pot into larger pots or out in the garden. As your plants grow, check how well rooted they are by gently pulling one out of the module tray. Once the roots have formed a network all the way through the compost, it’s time to put them on.

Which? Gardening Helpline

Which? Gardening has a helpline service, offering advice on a range of topics from how to dealing with pests and diseases to looking after your lawn. Members can also email with questions, so sign up today.

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