Plant summer bulbs now

April is the key planting window for many summer bulbs and tubers, with gardeners being urged to buy and plant now for flowers later in the season. (idealhome.co.uk) Ideal Home’s April 13 piece lists seven picks for planting this month: dahlia, lilies, gladioli, crocosmia, agapanthus, canna and begonia. Verve horticulture expert Tessa Ammonds said April is “a great time, if not the best” to get summer bulbs into the ground. (idealhome.co.uk) The Royal Horticultural Society draws a line between hardy and tender types: hardy summer-flowering bulbs such as lilies and crocosmia are planted in autumn, while tender summer-flowering bulbs including gladioli are planted in early spring. The same guidance says bulbs should be planted as soon as possible after purchase. (rhs.org.uk) That timing is tied to soil and frost, not just the calendar. Longfield Gardens says summer bulbs are generally planted in mid to late spring after frost danger has passed, with night temperatures around 60 degrees Fahrenheit and soil at 65 to 70 degrees Fahrenheit for heat-loving types. (longfield-gardens.com) The practical effect is that April works as a planning month in much of the United States, but not every plant goes in on the same day. Longfield Gardens says southern gardeners often plant from January to March, central areas from March to May, and northern areas from April to June. (longfield-gardens.com) Dahlias need the most patience of the group because they are frost-tender tubers rather than true bulbs. Longfield Gardens says most United States gardeners plant them outdoors between mid-April and early June, once frost risk has passed and the soil has warmed. (longfield-gardens.com) Gladioli sit in the middle: the Royal Horticultural Society calls them corms, which are bulb-like storage organs, and says most corms are planted in spring. The society also notes that many popular hybrids need lifting and dry winter storage in colder conditions. (rhs.org.uk) Planting method shapes the display as much as timing does. The Royal Horticultural Society recommends groups of at least six bulbs, says 25 to 50 may be needed for an impressive show, and advises planting most bulbs at two to three times their own depth. (rhs.org.uk) Colour planning is part of the pitch because different plants peak at different points in the season. Longfield Gardens says Asiatic lilies flower in early summer, canna lilies in midsummer, and dahlias continue into fall, which lets gardeners build a succession of blooms instead of a single burst. (longfield-gardens.com) The short version is that gardeners who want late-summer colour still have time in April, but the work starts before the flowers do: buy early, match each plant to local frost dates, and get the bulbs or tubers in before warm-weather growth begins. (idealhome.co.uk)