Once all danger of frost has passed, you will be able to plant out your hardened off half-hardy seedlings.

Preparing the Ground

Before planting out, prepare the site by removing all weeds and digging over the soil to one spade's depth. Rake over the area to produce a fine tilth. Water the young plants thoroughly, and then leave them to drain for an hour.

Separating the Plants

Break apart divided trays or packs to remove each seedling with its root ball intact. If plants are in trays without divisions, hold the tray firmly with both hands, and tap one side sharply on a hard surface to loosen the compost. Then gently slide out the contents in one piece. Separate each plant gently with your fingers, keeping as much soil as possible around the roots. Alternatively, remove each plant gently using a widger or other small tool, taking care not to damage the roots. If removing a plant from a pot, turn it upside down, whilst supporting the stem with a finger on either side. Then tap the rim against a hard surface to loosen the root ball from the pot.

Border Planting

If sowing a border, make up a planting plan showing the position of each cultivar, using any areas likely to be in shadow to grow those that are shade-tolerant (see the guide to shade tolerant plants for ideas). Mark the area for each plant with grit or a cane so that you can check the balance of colours, heights, and habits of each of the different cultivars to be used before sowing the seed.

Planting Distances

Space the plants out to cover the area. Leave space for them to grow, but aim for each plant to meet its neighbours leaves as it grows to cover the ground. Normal planting distances range from 15 to 45 cm (6 to 18 in) depending on the cultivar.

Planting Technique

Using a trowel, dig a hole for each plant large enough to easily hold the root ball. Ensure that each plant is at the same level as it was in its container, then use your hands to fill in around the plant, gently firming the soil around the base of the stem so that there are no air pockets.

After you have finished planting, gently loosen the soil surface between the plants with a hand fork. Then water the plants in well, using a rose on your watering can to ensure that soil will not be washed off the roots.