How to Grow Plug Plants

Plug plants are often better known as seedlings. They are termed plug plants due to the shape of the seedling, and its roots, when pulled out of the punnet and how they resemble a “plug”. Many annuals are sold in nurseries as plugs and these include bedding plants such as petunias, pansies, marigolds and the like plus vegetable seedlings as well.

Gardeners use plugs for two reasons;

1). they are often much easier to cultivate than traditional seed raising, and 2). they give the gardener more control over their planting arrangements than sowing seeds. However, while they may have some benefits over their seed counterparts they do have some drawbacks as well. Firstly, they’re not cheap especially if you’re planning to buy a bucketload. Plus, when planting plugs they can suffer from transplant shock – a condition that makes the seedling keel over until it they’re comfortable in their surroundings.

The good news is that both drawbacks can easily be overcome so here are some gardening tips to get you growing plug plants successfully.

Grow Plug Plants – Cheaply

If you want to grow plug plants cheaply then you have to do it yourself. Buying them from the nurseries in bulk is going to cost a small fortune and if you plan to do that every year then you’re throwing away money that could be used in your garden for other purposes.

The best time to start is in winter when all your plants are dormant and you have heaps of time on your hands. You will need a cold frame or greenhouse to keep your plug plants warm, some clean plastic punnets (you can reuse these provided they have been cleaned well with bleach between plantings), some seed raising mix and a small mist sprayer.

Fill the punnets up with the seed raising mix and then tap down to remove any air bubbles. This should now give you some clearance of a few millimitres at the top. Lay a few seeds in each plug and when they’re all done cover with a light layer of the seed raising mix. Spray with the mister and then label before placing into the cold frame or greenhouse.

Over the next few weeks monitor your plug plants as they begin to grow. Once the first few leaves break out of the ground they can be misted with some fish emulsion to help provide some much needed nutrients but this should probably only be done every 2 weeks or so.
Once your plug plants have grown two sets of leaves, at least, and the ground has begun to warm up with the first few weeks of spring you can begin transplanting your seedlings out into their garden beds.

Grow Plug Plants – Successfully

Once you plant your plugs they are no longer safe and secure and are open and avialable to a heap of problems and attacks – none more discouraging than finding they were the meal of some garden pest. However, there are ways to protect your plugs from snails and even woodlice and sowbugs. Barriers are much more effective than chemicals.

Another evil that your plug plant may suffer from is transplant shock. Plugs will go into shock once they are taken from their comfortable punnets and placed into their new location and the key is helping them recover from it. Giving them another dose of fish emulsion will certainly help as will covering them with a garden cloche, mainly overnight.

Amending your soil prior to planting also offers your plug plants a greater chance of success and well-rotted compost and manures can be an incredible welcoming party to any new seedling.

The first two weeks of any seedlings life, after being transplanted, is the most critical time for them. Once they’ve passed this time period their chances increase and they should continue to grow quite happily in your garden and provide the benefits you were hoping to achieve. is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Additionally, we participates in various other affiliate programs, and we sometimes get a commission through purchases made through our links.