Dahlia Bishop of Lancaster

For abundant flowering, it is good to follow a few simple rules, plant the tubers in a sunny location as soon as the last frost has passed, rich, fresh, and well-drained soils are perfect. However, stagnant moisture would promote tuber rot. Feel free to amend the soil with compost and sand if necessary. Work the soil deeply and enrich it, for example, with crushed horn or dehydrated blood. Place your tuber and crumble the soil well to fill the hole without air pockets. Your dahlia should be covered with about 6 cm (2in) of soil. At the end of planting, water abundantly once and then regularly for the first 6 weeks to help with rooting.

Dahlias are sensitive to cold, they need to be overwintered under shelter. In November, the first frosts blacken the foliage, so it is time to dig them up. Carefully unearth the tubers. Remove as much soil as possible. Let the foliage dry so that the tubers can replenish their reserves. Then cut the stems down to 10 cm (4in). Spread your bulbs in a crate on newspaper. Store them protected from frost in a dry, cool, and dark place, such as a frost-free garage or an attic. In the southern regions, close to the coast, where there are few frosty days per year, it is possible to leave them in place. In this case, simply cover the ground with a layer of leaves or straw for protection.

This tall dahlia, with its hollow stems, is not resistant to wind or heavy rain. To overcome this drawback, you can stake it but it's not very attractive. On the other hand, by pinching the stems early you can spread out the habit of the plant, which will offer more resistance to bad weather. Alternatively, you can remove the axillary flower buds to channel the flow of sap to a single flower, which will become larger and sturdier, though taller.