If you fancy saving seed from your own garden, you should start selecting plants now. Remember F1 hybrids do not come true from seed, so there is no point in trying to perpetuate them. Choose plants with the characteristics you want to preserve and mark them with a bamboo. Candidates for seed saving should be robustly healthy and true to form. They will be the last to bolt and have rich colour and good disease resistance. As the season progresses, take special care of these, but don't overfeed or spray them unduly natural resilience is what you want to foster.