How to plant, care for and grow Dahlia
|Name derived from||Named in honour of Dr Anders Dahl – Swedish Botanist and pupil of Linnaeus.|
|Sun Exposure||Full sun|
|Flower Colours||Large range|
|Frost Tolerance||Moderate – only severe frost can threaten it|
|Predators||Aphids and thrips|
Fun fact: the petals are edible and can be used in salads for decoration.
Dahlia is a tuberous root. There are about 30 species that originated in Mexico, America and Colombia. Dahlia can take the place of spring bulbs that have gone dormant over the summer months. Aztecs used the plant for its medicinal purposes as well as for animal food. At maturity, Dahlia will reach a height of 20 – 180cm.
Seasons and planting
Dahlia requires a well-draining soil, if your gardens soil has too much clay then add some sand and compost to improve its quality. You can apply mulch to the top of the soil to keep the moisture in. The plant prefers heat and enjoys being in the full sun. They can endure shade during midday which will decrease their need for water. When planting, the bulbs must be placed 15 – 40cm apart at a depth of 8cm. The lowest temperature that this plant can tolerate is 3°C.
When planting, ensure the tubers are pointed down. Water the plant deeply every three days. The plant will benefit from feeding it Hadeco Bulb Food regularly.
You might need to provide some of the taller varieties with a stake if they look like they are going to fall over. We recommend that you prune the plants back every now and again as this will promote new growth. You can maximize the size of the flower by reducing the size of the two buds next to it – allowing the central one to grow alone.
If you notice deformed/stunted growth or mottled foliage, the plant has been infected and should be discarded as soon as possible.
If you want to put the flowers in a vase, cut them in the morning – this will allow the stems to dry up in the heat of the day. Ensure that you cut the flowers just before they are about to bloom. As the season ends, the leaves of the plant may turn yellow, you can cut and break these leaves away.
If you would like to lift Dahlia, do it at the beginning of winter. Cut the stem roughly 5cm above the ground. You can then lift the tuberous root. If they were well fed, there should be an increase in the size and quantity of tubers around the crown. Do not wet the roots during this time.
Large crowns can be split as long as they each contain one old stem. You can also take cuttings from younger plants in the early summer.