Bulb Planting Advice

Growing Dahlias

Dahlias can be stunning border plants as well as cut flowers. They are surprisingly easy to grow and will withstand most types of soil. With the correct overwinter care, your dahlias can thrive year to year.

Planting

Dahlias should not be planted until after the last frost. For most parts of the UK, this is late April to Early May.

Dahlias will do best in well-drained soil and planted in full sun. Make sure to incorporate plenty of compost (Blom’s suggest John Innes No. 2) and plant the tubers in their flowering position at a depth of about 6 inches.

When the plants reach about 16 inches, you should pinch out the tips of the main shoot. If you desire the largest flowers, you should pinch out all but 3-5 tips. This will direct all the plants energy to these flowers.

Water regularly, and once the flowers begin to appear, apply a liquid feed approximately every two weeks.

Winter Storage

In the southern parts of the country, and especially where the soil is free draining, it is not essential to lift your dahlias. After the first frosts, you should cut the plants to the ground. The tubers should then be covered with a 3-6 inch layer of bark or compost to protect them from further frosts. In colder areas, the tubers should be lifted and stored over winter.

Cut the foliage down to ground level and carefully lift the plants out of the soil. Leave to dry and trim plants to approximately 8 inches, making sure to trim off any fine roots.

Store tubers in trays or wooden crates, packed with dry sand or peat-free compost. Store in a cool dry place and protect from frost.

Flowering Guide