Autumn’s cooler weather is a signal that it’s time to dig for treasure. But instead of unearthing gold or jewels, gardeners start tucking ordinary flower bulbs into the soil. Bulbs, a catch-all term we’ll use here for corms, tubers, and other underground storehouses for spring flowers, should be planted at least six weeks before the ground freezes. Once they’re planted in a sunny spot with well-drained soil, bulbs are almost foolproof. Your biggest challenge may be making room for all the cheerful daffodils and swan-necked tulips you’ll want to grow.
Pick bulbs that feel firm, not dry or spongy, and avoid any with signs of mold. Don’t worry if your bulbs don’t have leaves when you buy them. They’re shipped while they’re dormant, to make transplanting easier, and they’ll sprout when the weather changes.
Plant as soon as possible after you bring your bulbs home. If you must wait, store them in a cool, well-ventilated room. The refrigerator is fine, as long as they’re not near fruits like apples and pears. Some fruits produce ethylene, a gas that can cause the flowers to fail. If the bulbs are in bags, open them for better air circulation.
For the most beautiful flowers, start your bulbs off right. Most need humus-rich soil and full sun (that can be almost anywhere in the spring, until the trees leaf out). If you plant underneath trees, keep the bulbs near the drip line, rather than close to the trunk.
If your soil doesn’t drain easily, plant in raised beds, or use amendments to improve your garden spot. Bulbs dislike “wet feet” and will rot if they’re constantly damp.
Add some bone meal or super-phosphate to the planting holes, to help the bulbs develop strong, healthy roots.
Plant bulbs with the pointy ends up. (Don’t worry if you can’t tell which end goes up. The stem will find its way to the surface anyhow.)
Plant the bulbs about 3 times as deep as they measure in diameter. For example, plant a 2″ daffodil bulb at least 6″ deep. After planting, water them to eliminate air pockets.
Caring For Bulbs Next Spring
Bulb foliage can look messy when the flowers fade and the leaves start to yellow, but resist the urge to cut the foliage or tie or braid it to “neaten” the garden. Bulbs need their leaves for photosynthesis, the process of producing energy for next year’s blooms. Instead, plant annuals like larkspurs, field poppies, and Johnny Jump-Ups, which bloom at about the same time, to help hide the foliage. Grass-like liriope also makes a good camouflage. Wait until the bulb foliage dies naturally before you remove it.
Feed your bulbs after they’ve bloomed with a slow-release bulb fertilizer.
Favorites To Grow
If bulbs are like buried treasure, then daffodils are the gold in the garden. With their sunny yellow, snowy-white, sunset orange and cream flowers, they’re easy-to-grow and cheerful. Look for varieties that bloom from early spring into early summer for a long-lasting parade of flowers. Most “daffs” will return reliably in USDA hardiness zones 3 through 8. They’re seldom bothered by pests and need little maintenance, but after they bloom, water regularly if natural rainfall is scarce. Daffs like neutral to slightly acidic soil.
For an early start to spring, try snowdrops or winter aconites. As their names suggest, they pop up even under a late snowfall. Crocuses also wake up early, dotting the landscape with splashes of neon purple, lilac, and yellow. Muscari, or grape hyacinths, flower around the same time. Try mixing them in flower beds for a touch of deep blue and purple against the gold of your daffodils.
White summer snowflakes (Leucojum aestivum), which resemble Lilies-of- the-Valley, complement any color scheme. Each snowflake petal is tipped with an emerald spot, and the flowers are slightly fragrant.
Tips For Northern Gardeners
- Plant bulbs anytime the soil is soft enough to dig, but for best results, get them in the ground before mid-November. Gardeners in zones 1 through 4 can plant starting in late August or September, while zones 4 to 7 can plant from September into November.
- Dutch tulips and hyacinths, which come from cold climates, are good choices for your garden. Species tulips (most of which are hardy to zones 2 and 3) and Darwin hybrids will usually return as perennials in the north.
- Tulips are usually planted in northern gardens in September and October. Keep them watered if the autumn weather is dry. If the bulbs lose vigor, you may need to replace them every 2 to 3 years.
- For early spring color, plant crocus and snowdrops on south-facing slopes, or in high areas that get plenty of warm sun.
Most daffodil varieties will perform well up north. You can grow the trumpet and cup-shaped daffs that don’t hold up well in the south. Butterfly-type daffodils (those with split coronas) also do well in zones 3 to 6. Daffs should be planted a little deeper in the north than in the south, so the bulbs aren’t exposed when the ground “heaves,” or repeatedly freezes and thaws. Six to 8″ deep is ideal. If heavy spring rains threaten, use supports or stakes to keep stems and leaves from falling over.
Tips For Southern Gardeners
- Jonquils and tazettas, which include paperwhites, come from Mediterranean climates and perform well where the winters are warm.
- If you’re in USDA garden hardiness zone 9 or 10, plant pre-chilled bulbs, or choose bulbs that don’t require pre-chilling. “Pre-chilling” means putting bulbs into dry, cold storage for various lengths of time, so they’ll produce flowers in the spring. Generally speaking, spring and early-summer flowering bulbs need 6 to 20 weeks of dry storage at temperatures ranging from 35 to 45 degrees F. You can pre-chill your bulbs yourself, by keeping them in the refrigerator (where the temperature is usually 40 to 45 degrees F) for 6 to 8 weeks.
- Tulips and hyacinths, which grow beautifully in Holland, usually don’t return in the South, but they can be grown as annuals. For best results, choose early varieties that bloom before the hot weather arrives.
- Recommended bulbs for the south include snowflakes (hardy to zones 4 through 8); alliums (zones 4 through 10); criniums (zones 8 through 11).
- If you’re in hardiness zones 7 to 10, avoid planting bulbs where they’ll get hot sun from late morning into the afternoon. Daffodils and crocus can tolerate light shade in the deep South.
Tips For Western Gardeners
- Ranunculus are a good choice for USDA hardiness zones 8 through 11 and bloom as early as March if planted in fall. (The so-called “bulbs” are actually tubers.) Gardeners in zone 7 can plant in early spring, a couple of weeks before the last expected frost.
- Tulips grow well in the western mountain region of the U.S., where the climate is similar to their native lands. In zones 7 and 8, plant tulips in a spot that gets only morning sun, or in a shady location. Tulips don’t like wet oil or rainy summers, so promote good soil drainage by using sand or shredded bark.
- Try native bulbs that tolerate drought and summer heat, like Indian hyacinth, Mariposa lily, and Firecracker flower (Dichelostemma). These bulbs are often cultivated, not collected from the wild, to avoid depleting natural resources.
No matter what bulbs you decide to plant, choose your favorites early, before they’re sold out. Spring bulbs are ready to go and packed with promise. All you have to do is dig in.