Question: Which of the Spring flowering bulbs must be put in early, and which can wait until later?
Answer: All the narcissi, species and varieties, and the small bulbs, such as crocus, snowdrops, scillas, chionodoxas, and grape hyacinths must be planted early – in September – or early October to make root development before cold weather.
Tulips, Dutch hyacinths and iris can go in later – in October – generally, until the ground is still workable. This planting program varies with the part of the country.