How to Grow Dahlia Bulbs
1- When to Plant your Dahlia Bulbs
Unlike other bulbs such as Tulips, Dahlias like warm soils so plant your Dahlia bulbs during the warmer and longer days of spring. Dahlias are usually planted about the same time you would plant your vegetable patch. Dahlia bulbs can be planted as late as mid-June in most parts of the country.
2- Where to Plant your Dahlia Bulbs:
Dahlia is an accommodating plant - it will grow almost anywhere! Dahlias will thrive in full sun but can tolerate some partial shade - the more sun, the bigger the flowers. Try to select a location that receives at least 6 hours of sun, sheltered from the wind and with, and this is vital, good drainage.
3- How to Plant your Dahlia Bulbs:
Dig a hole twice as deep and wide as the Dahlia bulb. Put the tuber in the hole with the “eye” on the tuber facing up. The eye is the point on the shoulder, or crown, of the tuber from which the plant grows. If you are planting a number of dahlias in the same location, they should be separated by about 2 feet to give each plant room to grow. The shorter varieties can be planted closer together. Plan for the rows to be 3 to 5 feet apart depending on the size of the plant. Fill in with soil to just cover the top of the bulb. As you begin to see new growth appear, cover again with soil. Covering the stem gradually will allow the stem to strengthen so it can support the flowers. Unless it is a very dry spring, it is not be necessary to water at the time of planting. The tubers will begin growing with the warmth and moisture in the soil. It is vital that they form a root system early in their planted life to assure a strong and healthy plant. Watering at the time of planting may encourage rot but as soon as your Dahlias are growing above the ground, water deeply to encourage strong roots.
4- How to Care for your Dahlia Bulbs:
Young dahlia plants do not need a lot of water; in fact, excessive water can lead to rotting of the plant. For larger plants, a good rule of thumb is to water if the rainfall is less than one inch in seven days. Pots require more regular watering. As the plant grows, remove any broken or damaged foliage. Good air circulation, especially near the ground is needed by the plants to prevent powdery mildew. Once the plants are several feet high the lower leaves can be removed to increase air circulation. Your dahlias will continue to bloom prolifically right up until frost. A heavy frost will kill the plant so you may want to dig the half a dozen or more tubers the plant has produced. Those tubers can then be stored and grown next spring!