Plug Plants

No time to sow seeds? Take a shortcut with plug plants. These mini plants can save you time and money if you want colour and flavour in your garden this year.

It’s that time of year when even the least horticultural among us feel an urge to do something with their gardens. If you don’t have time, space or the equipment to sow seeds this spring, there’s still time to buy plug plants which cost far less than the more mature versions of plants that will be in the shops come early summer.

Plug plants are essentially mini-plants grown in their own cell. It’s as if your fairy godmother did all the hard fiddly work of sowing seeds, keeping an eye on them until they’ve germinated and then patiently pricked them out. You’ll still need to have a space outdoors to put the plants while they are growing on, but you’ve got a great head start.

The last chance to buy summer bedding as plugs is generally the end of April but some more tender vegetable plugs are sent out later, to be planted in the ground or in containers soon after arriving.

The key to success with tender plug plants is to wait until the last of the spring frosts have passed. These plants are still young, and a hard frost can damage or even kill them. If you don’t have space inside you could throw some garden fleece over them at night if you know the temperature is going to plummet.  

If you aren’t planting up straight away, check whether they have become root-bound, meaning they’ve outgrown their pots. You can tell by turning the plant upside down and seeing if there are roots protruding from the holes in the bottom of the pot. If there are, it’s time to put them into a larger pot.

At this time of year, these little plug plants are developing the root systems to supply water and nutrients to the leaves, flowers and fruit later in the season. So it’s critical that you give the roots plenty of space to grow. 

If you have a frost-free greenhouse or enough space indoors, you could start planting up hanging baskets and containers with plug plants, giving them plenty of room to develop and put down new roots. But these plants are still babies, so they will need some TLC and gentle handling before you place them outside when all danger of frost has passed.

What are the advantages of plug plants?

Less Fiddly

Plug plants are less fiddly than seeds

They arrive in their own ‘cell’ of soil and take away the hassle of thinning out seedlings from trays or pricking them out individually to pot on. When seedlings are small, they need very careful transplanting. Patience and a gentle hand are key. 

Because plug plants are grown in their own cell, there is far less risk of root disturbance – which can cause a check in growth. By the time you buy them, the plant is sturdier and it’s a lot easier to transfer them into a larger pot.

Cheaper

Plug plants can cost around half the price of more mature plants later on in the season – both from online suppliers and garden centres. “Plug plant sizes vary dramatically but most of ours are about 6cm. Our ‘teen’ range, most of which are raised from cuttings and are true to type, are 9cm,” says Marcus Eyles, horticultural director of Dobbies Garden Centres (dobbies.com). 

You can even buy houseplants as plugs for less than a more mature specimen would cost and nurture them yourself.

Less Waste

You may not want too many plants.

If you grow from seed, you may well end up throwing quite a few plants away as you find you don’t have room for all the seedlings. Vegetable plug plants in particular are great if you only want a few of a particular vegetable, as you can pick and choose. A packet of tomato or chilli seeds, for instance, is likely to produce far too many plants for the average garden.

“If people want to buy plug plants, I would recommend almost any vegetable actually including beetroot and salad onions,” says gardening expert, author and YouTuber Charles Dowding.

“Sometimes large and lush plants – which look great at point of purchase – do nothing but decline for a while until they recover from being in the new and more challenging conditions.”

Easier to grow

Some plants are difficult to grow from seed

“Begonias, bacopa, nemesia, osteospermum, verbena and lobelia are all more difficult plants to propagate and take time, therefore buying them when they have already been raised on to young plants will give you a head start for the season, plus could save time spent if unsuccessful in propagating from cuttings or seeds,” Eyles advises.

Others which can be difficult or take a long time to grow from seed include geraniums, begonias and dianthus. Dowding adds: “Good veg to buy [as plugs] are aubergines, chilli, pepper, celery, celeriac, grafted tomatoes, perhaps cucumber and melon too.”

How much care will they need?

“These are young plants, and we can still experience cold weather and frosts until May, so some TLC is required to grow them on,” says Eyles. “Plant into larger pots and place in a greenhouse, grow house, conservatory, or windowsill with lots of natural light. Make sure the temperature stays above 14 degrees C.

“In the same way that you would if growing from seed, you’ll need to get them used to colder temperatures, hardening them off in a cold frame over a period of seven to 10 days, moving them outside once risk of frosts has passed. Water carefully, ensuring not to over water.”

Plug plants are now available in garden centres throughout Ireland. If your local garden centre is closed, they can be bought online from a range of Irish suppliers. Visit quickcrop.ie, the gardenshop.ie, nightparknursery.com, fernhill.ie.