News: Grow Your Best Dahlias

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Grow Your Best Dahlias

There are few plants that are more rewarding and spectacular and easy to grow than the dahlia. If you can grow tomatoes, you can grow dahlias. The taller varieties require a little more work than the shorter bedding dahlias but you will be well rewarded.

Your dahlias will perform at their best in full or partial sun. Avoid a shady position as they require high light levels. For the border choose varieties that will be tall enough not to be in the shade of other plants. The shorter bedding dahlias will do best at the front of the border.

Dahlias are heavy feeders and require rich well-drained soil, add plenty of garden compost a week or so before planting or well-rotted manure when digging in the autumn. Give them plenty of room from competing plants, about 30cm apart. When planting lightly fork the soil and rake in a top dressing of bone meal. Plant the tubers 10-15cm deep, this will help protect against late frost and ensure the plant has sufficient moisture. If the tubers have started to sprout delay planting until any chance of frost has passed. If we do get a late frost, always likely, give them some protection. I find old boxes or upturned pots work well.

The taller dahlias should be staked at the time of planting to avoid any damage to the tubers. The canes should be about 30cm shorter than the expected height of the plant. Be careful not to over water, especially so when the plants are young.

For the taller dahlias, the following additional steps should be undertaken. These are not necessary for the shorter bedding varieties.

To encourage a bushy plant remove the top of the growing stem about a month after planting. Debudding. Remove the two outer buds from the three that form at the end of the flowering stem. This gives the plant a better show if all the buds are left the flowers tend to be covered up and lost in the plant.

A liquid nitrogen fertiliser feed in mid-summer is beneficial but remember that over fertilising will encourage foliage growth at the expense of the flowers.

Enjoy your garden
Chris Blom

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