How to create a perennial border

Start by finding out how much sun the spot gets. This determines which perennials you can use:

• Sun (6+ hours): E.g. coneflower, catmint, salvia, rudbeckia and ornamental grasses.
• Partial shade: E.g. cranesbill, Japanese anemone, lady's mantle and astilbe.
• Shade: E.g. hosta, ferns, Siberian bugloss and elephant's ears (bergenia).

Mark out the shape of the border with a garden hose or string. Soft, curved shapes often give a more natural look than straight lines.

The soil is the foundation of a healthy perennial border, and it pays to do the work thoroughly from the start:

1. Remove grass and weeds: Strip off the turf and remove the roots of perennial weeds such as ground elder and couch grass.
2. Loosen the soil: Dig or rotavate the soil to a depth of 25-30 cm.
3. Improve the soil: Add 5-10 cm of soil conditioner and mix it in well. If the soil is very poor, or the border needs raising, you can instead fill up with new topsoil.

Read more in our guide How to Improve the Soil in Your Garden.

• Height: Place tall perennials at the back (or in the middle if the border is seen from all sides) and low ones at the front.
• Groups: Plant in groups of 3, 5 or 7 of the same variety. This gives a calm and cohesive look.
• Flowers all season: Combine perennials that flower in spring, summer and autumn, so there is always something to see.
• Foliage: Ornamental grasses and perennials with attractive leaves give structure, even when nothing is in flower.

Find inspiration and advice on individual plants in our plant encyclopedia.

Container-grown perennials can be planted most of the year, as long as the ground is not frozen. The best times, however, are:

• Spring (April-May): The soil is moist, and the plants have the whole season to establish.
• Autumn (September-October): The soil is still warm, and the autumn rain helps the roots get going. The plants are ready to grow when spring arrives.

1. Position the plants: Set the pots out on the border according to your plan before planting. That way you can easily move them around.
2. Keep your distance: As a rule of thumb, small perennials are planted 25-30 cm apart and large perennials 40-60 cm apart. This typically equals 5-9 plants per m².
3. Plant at the right depth: Dig a hole slightly larger than the pot and plant the root ball at the same height as it stood in the pot.
4. Water thoroughly: Water well after planting so the soil settles closely around the roots.

A layer of bark mulch or Forest Mulch between the plants retains moisture, suppresses weeds and gives the border a neat, finished look. Spread a layer of 5-8 cm, and leave a little space around each plant so the mulch does not lie against the stems.

• Watering: Water regularly in the first year, especially in dry spells. After that, most perennials manage with watering only in longer periods of drought.
• Weeds: Remove weeds while they are small. See more advice in our guide to weed control.
• Cutting back: Leave the dead stems standing over winter. They give shelter to insects and food to birds, and many look beautiful with frost. Cut back in early spring before the new shoots appear.
• Dividing: Most perennials benefit from being divided every 3-5 years. Lift the plant in spring or autumn, divide it with a spade, and replant the pieces.