When learning how to plant bulbs, you will discover that there are two main flowering periods for bulbs – spring and summer – and that different varieties need planting at different times of year. Whether choosing the best summer bulbs or the best spring bulbs for your garden, a little consideration to planting at the correct time will make all the difference. Bear in mind that some bulb flowers, such as snowdrops, will break through the ground in winter, while others will extend their flowering season into the fall. Time it right, and you can enjoy a cheery carpet of snowdrops at the end of winter, through golden daffodils and colorful tulips in spring, exotic lilies and showy freesias in summer, right to the onset of fall, when generous dahlias and gladioli are still bearing glorious blooms.
When to plant bulbs – which season is best?
Summer bulbs – including many lilies, dahlias, begonias, alliums, agapanthus, crocosmias and gladioli – are planted in the spring. ‘It’s best to note that summer bulbs are not tolerant of cold temperatures, so they should only be planted when the ground is warm,’ says Aya Bradley, a gardening expert at The Golden (opens in new tab). Spring bulbs – including tulips, daffodils, crocus, fritillary and hyacinths – are usually planted in the fall. ‘These bulbs spend winter in the ground and flower in spring. They need many weeks of cold temperatures to break their dormancy and bloom to their full potential,’ adds Bradley. Fall is also the best time for planting winter bulbs such as snowdrops, although these can alternatively be planted ‘in the green’ in spring. Learn how to plant snowdrops to get the best results.
When should I plant spring bulbs?
The exact month in which you should plant spring bulbs will largely depend on your USDA plant hardiness zone (opens in new tab). Gabriel J. Croteau, certified master gardener and expert at Juliei Salone (opens in new tab), has the following advice: ‘If you live in zone 4 or 5, plant bulbs between September and October; for zones 6 and 7, plant them October to early November; for zones 8 and 9, November to early December is best; while bulbs in zone 10 should be planted late December to early January.’ After planting bulbs in the fall, some gardeners have problems with squirrels digging up their freshly planted bulbs. ‘To deter squirrels, simply sprinkle cinnamon on top of the soil and around the area where bulbs are planted,’ says Joanna VonBergen, gardening expert and founder of Gingham Gardens (opens in new tab).
When should I plant summer bulbs?
As when planting spring bulbs, the best month to plant summer bulbs will depend on your USDA plant hardiness zone. ‘For zones 8-10, plant summer bulbs in late March to May; for zones 4-7, plant them in May or June,’ says Croteau. For a general rule of when to plant bulbs during the spring, summer bulbs can be planted as soon as the soil temperatures are consistently over 50°F. You can start off more tender summer bulbs, such as dahlias and begonias, as early as late winter if you keep them indoors. Doing this will give them the best possible head start. Learn how to plant dahlia tubers and how to grow begonias to ensure a stunning summer show. Unlike spring bulbs, summer bulbs don’t benefit from a frosty winter period. ‘Depending what gardening zone you are in, some summer bulbs will not survive winter temperatures and must be lifted and stored indoors,’ says VonBergen.
When to plant bulbs in pots
Bulbs can be planted in pots at the same time as they can be planted in the ground. However, it is possible to bring the planting time forward slightly if you keep the pots in a sheltered spot. ‘If you plant spring bulbs in pots in the fall in a cold climate, the flower pots must be stored in an unheated garage or cool basement,’ says VonBergen.
Can you plant bulbs at any time of year?
When deciding when to plant bulbs, bear in mind you shouldn’t plant them at just any time of year. However, you can extend the planting window. ‘As long as the soil isn’t frozen or waterlogged, you can plant spring bulbs as late as Christmas, or even January or February in a colder climate. Cover the area with mulch,’ says Croteau. Summer bulbs shouldn’t be planted too early in the year, or they could be damaged by frost before they have a chance to grow. Too late and they will fail to thrive in the summer. June is the latest you should plant summer bulbs. ‘Spring bulbs need a period of dormancy to bloom, while summer bulbs do not. Planting at the wrong time of year can result in the bulbs not blooming or producing fewer blooms than usual,’ says Stephen Webb, founder of Garden’s Whisper (opens in new tab). ‘However, if you live in an area with a mild climate, you may be able to get away with planting bulbs at other times of the year.’
