The first crocus of spring. Sunny yellow daffodils naturalized under trees. Beds full of crimson tulips—it all starts now.
After gardening all summer, it’s hard to add yet another chore to the pile of things to do this month, but planting bulbs should be near the top of the list. Getting them in early not only affords you the best selection at the garden center, but gives roots time to grow in still-warm soil, preventing frost heave and providing the best start to next spring’s bloom.
Pick a location that gets plenty of sunlight, particularly if you intend for your bulbs to come back year after year. Most bulb species bloom well the first year, but here in Colorado they tend to diminish with each successive growing season. Especially in the case of tulips, assume that you will need to replace them annually for the best display. Even other species will need ideal growing conditions if they are to increase in size and number.
Spring storms can devastate a bulb display in full bloom. Selecting a site with a northern exposure—or at least one away from a heat-retaining wall—will delay growth in the spring. We may be anxious for those first flowers, but we can’t enjoy them if they’re broken under a foot of heavy snow.
Like all gardening endeavors, a successful bulb garden starts with the soil. If you are starting from scratch, be sure to add plenty of compost or well-rotted manure—a three to four inch layer is best. This is also the time to add any other nutrients, especially phosphorus or potassium, that your soil may be lacking. Dig it all in at least a foot deep, where the roots will be.
Now it’s time to pick out your bulbs. Catalogs abound, but it is late in the season for ordering, both because time is short, and because many varieties will be sold out. Keep in mind that the larger the bulb, the larger the flower will be—and the more they will cost. Buying bulbs already bagged (rather than from open bins) ensures that they all match the photo on the label.
I always come home with many more bulbs than I’d intended to buy. Because they are planted deeply—usually four times their height—digging all those holes can be a challenge. If you are planting a large bed, it might be worth your time to simply remove all the soil to a depth of 6 to 8 inches, place the bulbs where you want them, and then cover them back up again. Various “bulb plants” are sold for planting individual bulbs, and you can try those as well.
By far, one of the best gardening investments I’ve made is a bulb-planting augur. Similar to the bit used to drill water wells, it is a long piece of metal that fits into your electric drill. A spiral blade running up the shaft excavates soil as you simply pull the trigger and stick the bit into the ground. Using it, I can dig over 100 bulb holes in a matter of minutes.
Take a moment to make sure your bulbs are root-end down. Spacing depends on the size of the bulb and whether or not you expect it to produce offshoots. Grape hyacinths are prolific in our area, reproducing both by bulb division and by seed. On the other hand, daffodils grow slowly if at all. An orderly arrangements gives a formal effect, while random placement is more natural looking. Bulbs look best when planted in a clump rather than strung out in a line.
To avoid damaging your bulbs, be sure to mark where each one is located (popsicle sticks are great for this) if you will be adding more plants in the spring. Low-growing plants such as alyssum, snow-in-summer, or one of the ground-hugging veronicas provide a lovely complement to your hyacinths and jonquils.
Once your bulbs are nestled safely underground, add several inches of mulch to reduce weeding, keep soil moist and protect them from wild fluctuations in soil temperature. Then sit back, relax, and wait for spring.
Caring for your flowers is easy. Keep them watered if snow or rain is scarce. Weeds ruin the look of a flower bed; mulch or a groundcover will keep them in check. Remove flowers after bloom to divert the plants’ energy to the roots. Let foliage remain on the plant until it dies naturally. The best time to add additional fertilizer is during the growing season, while beds are in full bloom. Once foliage turns brown and drops off, the bulbs are dormant, and fertilizing will not affect them.
Pests are few, but squirrels and other rodents relish many bulbs, especially tulips. A physical barrier may be needed to keep them from harvesting their dinner from your flower bed. If all else fails, plant daffodils. They’re poisonous.
Among the earliest flowers to appear each spring, bulbs provide a display when little else is in bloom. My garden wouldn’t be complete without them.
More information: Colorado State University Extension Fact Sheet