Delphiniums need to be in the sun for at least half of the day, so choose a spot in the garden accordingly. Soil must be fertile and free draining. If your soil is poor then dig in plenty of new compost or organic matter to enrich it. Water plants well to establish and maintain a regular watering and feeding schedule throughout the months that the plant is growing. Flower spikes may need to be tied to a stake to stop them from blowing over and getting damaged.  Remove dead flowers and once the plant has finished its 1st flush of flowering in late May or early June, chop plant back by half to encourage a second flush later in the summer. This is often called the ‘Chelsea Chop’, as plants tend to be nearing the end of their 1st flush around the time of the RHS Chelsea Flower Show.