Dahlia Rosario

The decorative Dahlia 'Rosario' is easy to grow in all regions. Here are a few simple rules to follow to enjoy its beautiful and generous flowering. Plant the tubers in the sun after the last frost. A rich, moist, and well-drained soil will be greatly appreciated. Avoid any stagnant moisture that promotes tuber rot. Amend your soil with compost (in case of poor soil) and sand (for drainage) if necessary. Work your soil deeply and enrich it with crushed horn or dehydrated blood, as desired. Place your tuber and crumble the soil around it to fill any air pockets. Your dahlia should be covered with about 6cm (2in) of soil. Water generously at planting and regularly during the first six weeks to aid in rooting.

Dahlias are sensitive to cold, so they need to be overwintered. In November, the first frost turns the foliage black, which is the 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 to 10cm (4in). Spread out your tubers in a crate on newspaper. Store them in a frost-free, dry, cool, and dark place, such as a garage or attic. In southern regions, close to the coast, where there are few freezing days per year, it is possible to leave them in place. In this case, simply cover the soil with a thick mulch (leaves, straw...).

Pinch the stems early (from the 3rd or 4th week after planting) to make your dahlia more compact and branched, and therefore more resistant to bad weather (wind, rain). To do this, use your nails to cut the terminal shoots just above the previous leaves. Otherwise, you always have the option of staking, but the aesthetic result may not be the best taste.

Slugs and snails are very fond of these young shoots. Protect them!