September 5, 2001
Stillwater Gazette
Betsy Halden

Selecting and planting spring-flowering bulbs

One of the joys of fall gardening is selecting and planting spring-flowering bulbs. It’s fun to envision how pretty the bright blooms will look next spring after our Minnesota winter. Spring-flowering bulbs offer color and fragrance before many other plants awaken from their winter nap. Local garden centers offer a wonderful array of spring-flowering bulbs. We can choose from traditional bulbs such as daffodils, tulips, hyacinths, or the less familiar such as squill, giant onion, or guinea-hen. A small investment of time and money this fall can give us the reward of lovely flowers next spring.

Selecting bulbs. After deciding which types of flowers you want in the spring, select only firm, solid bulbs for planting. Avoid bulbs that are shriveled or light-weight. bulbs that are discolored by mold or that contain soft spots should be avoided.

Size does matter when selecting bulbs. The bigger the bulb the better its flowers. Smaller bulbs often bloom but you get more bang for your investment with the larger bulbs.

Planting bulbs. October is a good time to plant spring-flowering bulbs. Bulbs should be planted when soil temperatures begin to cool. Soil temperatures in early fall are ideal for good root development. However, some bulbs like tulips may emerge in the fall if they are planted in early September before the soil begins to cool. We can plant spring-flowering bulbs as long as the ground remains unfrozen. When the bulbs are planted in October root systems have a better chance to develop. Select the planting site carefully. The soil should be fertile and well drained. Bulbs planted in wet sites will often be short-lived. Amending poor soils will go a long way in ensuring dependable blooms for the spring and for following springs. The more suitable the site, the longer the bulbs will last.

Most bulbs prefer a sunny site. Bulbs often grow well beneath high branched deciduous trees. The bulbs will flower before the trees fully leaf out. After the bulbs have flowered many of them can tolerate the light shade from the tree.

Bulbs are generally planted along the foundations of homes or in beds or borders where we can have an unobstructed view of their blooms. You may want to consider planting bulbs with ornamental grasses and other perennials that will hide the foliage as it yellows. Plant bulbs in large groups for maximum visual impact. Bulbs planted alone or in rows like soldiers are not nearly as effective as large sweeps or drifts of color. For a naturalized look, simply toss handfuls of bulbs in the garden and plant them where they land. The smaller bulbs should be planted in large groups (20 or more) or elevated in a berm or rock garden so they can be seen easily. You can mix bulbs with different bloom times to achieve a long-lasting display. One friend says she is careful to select early-, mid- and late-blooming daffodils so she can enjoy them as long as possible.

Proper bulb depth is another important planting requirement. The general rule is to plant the bulb at the depth of 2 ½ to 3 times the height of the bulb. Tulips, daffodils, and hyacinths are often planted 6-8 inches deep. The smaller bulbs like squill, snowdrops, and crocus are planted 3–4 inches deep. Larger bulbs can be spaced 4-6 inches apart while a 2-3 inch spacing is adequate for smaller bulbs.

Remember to plant your bulbs right side up. This means planting the pointed end up for bulbs like tulips, daffodils, hyacinths, squill and others. The right end can be hard to identify for some of the more unusual bulbs or bulb-like structures. It may take careful looking. If no roots or buds are apparent, you can plant some bulbs on their sides. The bulb will find the sun and bloom normally with only a little extra effort.

There are a number of tools made for planting bulbs. Bulb planters, trowels and auger attachments for electric drills are available to assist in bulb planting. For a mass planting of bulbs in an area, remove the soil to the proper depth with a shovel. Place the bulbs in the desired arrangement or pattern and then carefully backfill with soil.

Fertilizers like 5-10-5, Bulb Booster, or bone meal can be incorporated into the soil at the time of planting. Bone meal is often slower acting and more expensive than the others. These fertilizers are more important for the development of next year’s bulb than they are for the upcoming flowers of this year’s bulb.

After planting be sure to water the area thoroughly to provide plenty of moisture for root growth. The addition of a light blanket of mulch on top of the soil will moderate soil temperatures. This will allow the bulbs a little more time for root growth before the ground freezes. The mulch layer will also conserve moisture in the soil the following summer.

If you are interested in becoming a Washington County Master Gardener, please call the Washington County Extension Office, 651.436.6803 for more information. Or you can FAX your request to 651.430.6801. The deadline for new applications is September 17.

Betsy Halden is a Master Gardener with the University of Minnesota Extension Service. University of Minnesota Extension Service materials were consulted in the preparation of this column. You can reach Betsy Halden at eahalden@comcast.net