Unwins Seeds

How to Grow Bedding Plants

Bedding plants are perfect for planting in patio pots, hanging baskets and for filling spaces in borders. Summer bedding plants are frost tender, which means that they survive until the first frosts in autumn, after which they should be replaced by winter hardy bedding plants.

Medium Plug PlantsInstructions for medium-sized plug plants

When they arrive:

Remove the cardboard packaging and water the plants on arrival.

  • Your plants are packed safely inside a micro-propagator, which is ideal for keeping your bedding plants safe and warm until they are ready to be potted up, they can be safely left for a few days but do not allow plants to dry out. Make sure there isn’t too much water in the bottom of the tray, place the lid on the top and position on a bright windowsill, but not in direct sunlight.
  • Remember to keep your micro-propagator – it’s reusable! It’s also useful for germinating seeds or growing micro-veg!

Potting Your Plants Up & Growing Them On:

Pot up into trays or individual pots - our Potting On Kit is perfect for the job. When doing so, handle the plants carefully by the leaves to try and avoid damage to the stems. 

  • Fill the pots or trays with good compost with a little slow-release fertiliser mixed in.
  • Use a dibber or pencil to push the plants out through the base of the plant tray to avoid damaging the plant.
  • Handle each plant by the plug root ball, rather than the stem to avoid damage.Poptting on medium plug plants
  • Grow on for a few weeks in a light, frost-free place, but try to avoid direct sunlight. Keep them moist but do not over-water.
  • Some varieties naturally grow tall and leggy. They can be encouraged to ‘bush-out’ by pinching out the growing tip. This is done literally by pinching off the top of the plant just above a branching point.
  • When plants have grown and formed a good root system, begin to harden them off by leaving them outside during the day and only bring them in at night, or by putting them in a cold frame.
  • After about 2 weeks of hardening off, leave them out at night but only if no frost is forecast.
  • Bedding plants can be planted outside from late May, or as soon as all risk of frost has passed.
  • Most bedding plants need to be spaced at 20-30cm/9-12in apart, depending on their overall size. (Check catalogue for eventual height/spread of plant – the larger the plant, the more growing space is required).

Large plug PlantInstructions for large-sized plug plants

When They Arrive: 

  • Remove the plants from the packing straight away and sit them in a tray of shallow water, allowing the plugs to fully soak.
  • Once the plugs have soaked through, remove them from the tray of water and allow drain.
  • One of the best things about our large-sized plug plants is that it isn’t necessary to pot them up and grow them on before planting outside, although we recommend that you do for best results.

Planting large plugs straight outside:

  • If planting straight outside without potting on first, make sure there is no risk of frost first. Late May is usually fairly safe, but different locations may vary.
  • Before planting your large plugs, thoroughly dig and water the soil first. Doing this provides an easier environment for the young plants to establish their roots.
  • Dig an individual hole for each plug, deep and wide enough for the entire root ball. Water-in after planting.

Potting on large plugs:

  • We recommend that you pot-on your large plugs as soon as they arrive for best results. Potting them on first allows them time to develop a strong, healthy root system. Our Shuttle Trays with 9cm pots are ideal.
  • Use a dibber or pencil to push the plants out through the base of the plant tray to avoid damaging the plant.
  • Handle each plant by the plug root ball, rather than the stem to avoid damage.Pot each plug into a 9cm (3in) pot using a good multi-purpose compost or a container compost.
  • Water after planting to settle to roots and leave to grow-on in a light, frost free place until all risk of frost has past and they can be planted outside.

TIP: Plant up containers and hanging baskets about a month before you put them outside (if you have space to do so) this gives them a chance to establish.Planting up Hanging Baskets

TIP: When planting in any container, it’s advised that you mix Gro-Sure Slow Release Plant Food into the compost. This helps the container hold on to moisture for longer and feeds your plants continuously throughout the season, saving water and reduces the need for additional feeding. 


  • Water well during hot, dry spells, paying particular attention to containers and baskets which need lots of water.
  • Dead-head plants regularly to encourage a longer flowering season.
  • Feed regularly during flowering – Gro-Sure All Purpose Plant Food or a weak solution of tomato food are  ideal. Alternatively use slow release granules, which can be incorporated into the compost or soil at planting time.
Back To Top

Sign Up for our FREE newsletter - Full of great tips and offers

By submitting your email address in the box below, you agree that Unwins may send you special offers about their products and services by email in the future