Dahlia is a flowering plant that is native to the subtropical areas of South and Central America. There are about 30 species of Dahlia known to humans, and more than 20,000 varieties are grown in different parts of the world. The typical Dahlia plant grows to a height of about 12 inches to 6 feet. It blooms in late summer and autumn. Its flowers are found in a wide range of colors, like white, purple, pink, yellow, orange, etc. It is quite prone to powdery mildew and viruses, aphids and leaf hoppers. The common problems with this plant are crown gall disease, root rot disease, wilting, etc.
Best Time to Plant Dahlia Bulbs
Dahlia needs a ground temperature of approximately 60 degrees. This is mostly possible in spring with longer and warmer days. To be more specific, ideal time for planting Dahlia bulbs is from mid April to May.
How to Plant and Grow Dahlia Bulbs
Dahlia bulb needs to be planted in an area where bright sunlight is present for more than six hours a day. Less than the recommendable sunlight exposure will result in taller plants and less blooms. The area needs to be protected from high wind. The soil should be warm and well-drained, but not over-drained. If water stays in the soil for extended periods of time, you will need to build up the soil accordingly. If the soil is too heavy, you may add a required amount of sand, peat moss, or bagged steer manure to loosen and lighten it. This will ensure better drainage as well. The pH level of the soil should be anywhere between 6.5 and 7.0.
Dig the soil to a depth of 12 inches. Work on the soil well, removing small stones, weeds, and other unwanted materials. Add required amounts of well-rotten manure or compost to the hole. Mix it well with the soil that is already existing. Plant the Dahlia bulb at a depth of 4 inches, keeping a space of 12 inches between each of them. Place the bulbs horizontally, such that the sides with most eyes point upwards. Cover it with soil and gently firm down the soil with your hands. Do not water the Dahlia bulbs till they sprout and come out of the soil. However, you may need to water it, if it's very hot. Do not cover the planted area with bark dust or mulch. This will not allow the soil to warm up sufficiently and the bulb to sprout properly.
Once you see growth, keep watering thoroughly, once a week. Mulch regularly to maintain moisture content of the soil. Add a required amount of fertilizer, which is high in phosphorus and potassium content. You should add it, 30 days after planting the Dahlia bulb. Repeat the application again after 3 - 4 week's time. Experts on Dahlia plantation recommend staking the Dahlia plants that reach above 3 feet in height. You may get a staking product from a local garden center. Remove weeds from the surroundings regularly, to ensure good Dahlia growth. If you wish to have shorter, bushier plants with better stems for cutting, you should pinch or cut the center of the Dahlia shoot right above the third set of leaves. If you have to cut out flowers, the ideal time is early in the morning.
If you choose to grow Dahlias in containers, go for a low growing or a dwarf Dahlia variety. The size of the container should not be more than 11" x 11" per bulb. Water the soil sparingly. Do not overload the pot soil with fertilizers and manures. These are basic instructions on planting Dahlia bulbs the ideal way.