The mercury (or red-dyed alcohol) creeps farther down the thermometer. Glimmering morning frost that highlights the world around us gives way to a bone-chilling freeze. Autumn colors fade from the hillside, leaving shivering, naked trees in their wake. Fall slowly gives way to the winter creeping up behind it.
As temperatures dip, many gardeners find time for one last activity, a celebration of a gardening rite of autumn — planting bulbs. It’s the time of year to plant spring-flowering bulbs such as tulips, daffodils and hyacinths.
Recently, I met with some of my Master Gardener volunteers who were planting tulips at the historic Craik-Patton House museum to discuss the finer points and little known facts about bulbs.
Tulip trade history
Tulips are the most popular bulb on the planet. They’ve been popular since well before Tiny Tim and his ukulele tiptoed through the tulip patch.
Anyone who has read Michael Pollan’s “The Botany of Desire” knows that the Dutch are well known for growing the majority of the world’s tulips. You also will have learned that when the tulip was first introduced to the Netherlands from its native North Africa and Iberia, it was so popular it was traded as currency.
It was also believed to be the cause of the first economic bubble and bust. In 1637, the price of a single tulip bulb was 10 times the annual wage of a skilled craftsman. Some sources say that the value of a single bulb could have been as high as $1.5 million.
These values were for a new variety of tulip with stripes in it. Before then, all tulips were solid colors, so the stripes were a sought-after novelty.
Unfortunately, it was not genetics but a virus that gave the tulips their variegation. The tulips started failing, and one day, in the blink of an eye, the price of tulips plummeted and many found themselves in financial ruin. The whole episode is called “tulip mania,” which is a term used to describe economic bubbles to this day.
Layers of bulb anatomy
Bulbs are an interesting study in plant anatomy and growth. It might be hard for some to imagine, but a bulb is, in fact, a complete plant in a condensed package. For this discussion, let’s talk about a bulb people are most familiar with — the onion.
When you slice open an onion, the first thing you notice is the rings. Those rings are actually scales that will be the leaves when the bulb sprouts. They store the food the plant will need to survive until it can grow leaves to start making food.
The stem of the plant is actually that hard little bit at the base of the onion that you cut out. From that basal stem, the leaves grow up and the roots grow out from the bottom.
There’s also a tiny little embryonic flower found right in the middle of the bulb. It will not start growing until the bulb has received a prolonged period of cool temperatures, called chilling, to begin developing. That’s why we plant spring-flowering bulbs in the fall — they generally need 15 or more weeks of cold in order to flower. This is sort of a built-in timer so that the plants don’t flower before winter and freeze.
If you want to force tulips, daffodils or other chilled bulbs to bloom indoors at any time, you’ll need to plant them in pots and stick them in the refrigerator for a few months. That is, if you are willing to give up the space reserved for a six-pack of beer for a six-pack of tulips.
Planting bulbs in the garden
All in all, bulbs are one of the easier things you can plant and grow in the garden. There are just a few simple tips and rules you need to follow to have success with bulbs. Here are some things to keep in mind:
Select healthy, plump bulbs. Those that have loose skins are dehydrated and old. Also, the bigger the bulb, the larger and healthier the bloom will be.
Plant bulbs in large masses for best effect. Beds full of tulips and daffodils look better than single plants.
Preparing a planting bed 12 inches deep will have the best results, but you can plant bulbs in individual holes if need be.
Plant bulbs right side up. Unlike dropping a seed in a hole, bulbs do really have a top and a bottom. Usually the pointy end is the top and the bottom has the basal stem.
If you don’t have the directions for planting depth, plant bulbs three times as deep as their diameter. That means a 1-inch-wide bulb should be planted 3 inches deep, a 2-inch bulb 6 inches deep.
Most bulbs should be planted about 6 inches apart. Daffodils should be planted 8 to 12 inches apart to let them spread and naturalize.
Fertilize bulbs when planted by using bone meal and superphosphate by adding it to the bottom of the planting hole or bed. Add additional fertilizer as top dressing each year.
Bulbs such as tulips and hyacinths should be dug up every three years or so and separated. The planted bulb will grow new side bulbs which need to be removed. If there are too many, blooms will become smaller until the plant stops blooming altogether.