Plant Bulbs In Containers for Spring Flowers
Among spring’s greatest visual joys is a fat container sporting thick green spears of emerging tulips, daffodils, and other flowers. And when the flowers emerge tightly circled, like beautiful eyes following wherever you go, there’s little that can compare. The time to make sure your spring will be full of beautiful flowers from bulbs is now, in the fall, to give them a chance to establish roots and to chill-out over the winter, just like most gardeners do.
Don’t get us wrong. We love spring blossoms from bulbs as they poke out from the thawing ground, sometimes even through the snow, in our borders and gardens. And there’s little that’s as impressive as a huge plot of daffodils, their bright petals announcing sunny days, turning through the day as they follow the light. But growing bulbs in containers is a great way to add spot-specific color and interest. They’re especially useful to the small gardener, even apartment dwellers with verandas, in that they provide a space for growing color where none may have existed. Best of all? Growing them is easy.
Almost any spring-flowering bulb will do for container planting. And as you plan your bulb containers, consider planting major flowering bulbs like tulips, gladiola, and daffodils with smaller flowers like crocus, snowdrops, windflower, or grape hyacinth (though the latter tends to spread and take over pots). Combinations of bulbs will give you both staggered blooms and a layered, understory appearance.
Drainage is particularly important to flowering bulbs. Make sure any pot you use has drainage holes at the bottom and, if they’re deep enough cover the bottom of the pot with broken pottery shards or stones before adding soil. Don’t use garden soil. A rich mix of home-made potting soil (scroll down) with plenty of compost and wood chips or sand to aid water conduction or an organic potting soil from your favorite supplier is ideal. Soil that doesn’t drain well and remains soggy encourages bulb rot. No one wants that.
Choose pots that give enough depth for proper bulb planting. A general rule is to have three inches of soil beneath your bulbs. How much soil to have over your bulbs depends on the plant (most bulbs come with planting instructions). If you’re layering different types of bulbs, put the larger bulbs on the bottom and the smaller ones near the top. Always leave an inch of the pot’s rim visible above the soil to help with watering.
Don’t be afraid to crowd bulb in the soil. A pot that is 20 inches in diameter will easily hold 30 tulip bulbs. Another grower claims that a 24-inch container can hold 50 tulips, 30 large-flowered daffodils, 50 small-flowered daffodils, or 100 minor bulbs, like Crocus, Muscari, Scilla, or Iris species or cultivars. Experimentation will tell you what works best for your conditions.
Gently screw the bulbs root side down (duh!) in to the bottom three inches of soil to help them stay in position. To get the emerging leaves to grow up and out, position the flat side of bulbs so they face the wall of the pot. Or point them in the other direction and plant them in the middle with a circle of lesser bulbs planted towards the outside. The bigger blossoms will crowd the center, framed by the smaller blossoms.
Bulbs need to overwinter in ground that doesn’t freeze hard. During this chill period, bulbs begin to grow roots. This suggests you’ll want to put them in the biggest pots possible and mulch them as deeply as the rim of your pot allows, especially in the colder zones. Some gardeners bring their pots inside the garage or basement to overwinter, but this can be a difficult task if pots are large and heavy. You’ll need to decide which method is most appropriate to your winter conditions and physical capabilities.
Because bulbs aren’t truly dormant during the winter, you’ll need to make sure the soil in your pots doesn’t dry out completely. If conditions warrant, pull back the mulch and give them a drink during dry periods. If you’ve taken your pots inside, get them out early ahead of the last frost so the bulbs can react to the changing conditions. There’s no more promising sight than when the first shoots appear. Don’t be afraid to add a touch of organic fertilizer before the blossoms show. Once they do, keep the soil moist — but not soggy — to encourage the flowers to stick around.
After blooming, the plants leaves will begin to yellow and die back. Keep watering even as this happens, stopping only when the leaves appear to be entirely gone (some gardeners plant lettuce or radishes in the pot during this time to take full advantage of the space and soil). This is the time, usually about the middle of summer, when it’s time to dig up your bulbs and place them on newspaper in the garage or basement to dry. When the soil that clings to your bulbs is cumbly dry, clean the bulbs and remove any dead growth. Store them covered in a cool dry place until fall arrives and they’re ready to plant again.