Jennifer Schultz Nelson
Extension Educator, Horticulture
Though we are surrounded by signs that the growing season is coming to a close and winter winds will soon be upon us, this is the season to plant some signs of spring—spring blooming bulbs that is.
Location is critical in planting bulbs. Bulbs in general will perform best in well-drained soil. Clay soils commonly found in our area typically do not drain well. Excess water in the soil surrounding bulbs promotes rot and will eventually kill the bulbs.
Improving drainage in heavy clay soil with organic materials such as compost or shredded leaves will help encourage healthy bulb growth. Besides issues related to poor drainage, unimproved clay soils can compact and restrict bulb growth, resulting in bulbs that slowly decline rather than multiply.
Another factor in the location equation other than the soil quality is the actual physical location. Part of the joy of spring bulbs is seeing those first green signs of spring emerge from the cold ground. In my opinion everyone should plant a few bulbs near spaces you see every day. My earliest blooming bulbs, some dwarf iris (Iris reticulata), are planted right alongside our driveway where my husband and I pass by twice each day. Our first glimpses of these flowers gives us hope that spring is near.
Iris reticulata are relatively small flowers, only about six inches tall. They are also rather delicate, with thin grasslike foliage and fairly short-lived flowers. To maximize their impact, I planted several of these bulbs in a group, rather than as individual specimens. I also planted them in a spot that I know will not have any other plant material competing for attention at the time these bulbs bloom. By the time any of the other perennials in this part of my garden begin to grow, the Iris reticulata are an early-spring memory—even their thin foliage has begun to fade away.
The bulk of my bulb planting has been dedicated to daffodils. They are one of my favorites, not just because of the wide variety of shapes, sizes and color combinations available, but because they are poisonous. This translates to: "this is one plant no furry creatures will eat in my garden". I am also a big fan of daffodils because they multiply and naturalize beautifully, without having to divide them often, if at all.
Tulips are beautiful choices for the spring garden, but at my house they would just be an engraved invitation for the local wildlife. Also, in our heavy soils tulips tend to be relatively short-lived. After about three or four years it is not uncommon for tulips to begin to decline, first failing to bloom, eventually dying off. Without a doubt some gardeners have exceedingly good luck with tulips they've had for years and years. This seems to be the exception rather than the rule, as I've seen some sources encourage gardeners to treat tulips as annuals, planting new bulbs each year rather than expect the original bulbs to give a repeat performance after their first year.
Tulips and daffodils tend to be the stars of the spring garden, but there are a lot of lesser known bulbs available that are attractive in their own right. Galanthus, or Snowdrops, are one of the earliest blooming spring bulbs, often blooming with snow still on the ground! Iris histroides and I. danfordiae are some other early bloomers that I will be adding to my garden alongside the I. reticulata we have enjoyed for several years.
Another lesser known bulb that I have grown to love is Scilla siberica, or Siberian Squill. These small blue flowers are only about six inches tall and appear after the earliest spring bulbs in my garden. They naturalize readily, and have filled an area of my garden with a blanket of gorgeous blue. They are not bullies in the garden. They emerge, bloom, and fade away before the bulk of my perennial garden has even shown signs of life.
A common question on planting spring bulbs is: "How deep do I plant my bulbs?" A good rule of thumb is to plant bulbs two to three times as deep as they are tall. Measure the depth of planting from the bottom of the bulb. Plant bulbs right side up—the "right side" is generally more pointed than the root end. If this distinction is not obvious on your bulb, plant the bulb sideways and Mother Nature will sort it out.
When purchasing bulbs, choose unblemished, firm bulbs with little or no new growth. Keep in mind that for a given species, larger bulbs are more mature and will produce larger or more flowers than smaller bulbs. Bargain bulbs are no bargain if they are small for their species. They will not flower as well if they flower at all. This is one situation where you get what you pay for.
Before the winter winds blow, take some time to plant a few spring bulbs. You will be glad you did as you watch the fruits of your labor unfold next spring.