When to Plant Spring Blooming Bulbs in Colorado

When determining when to plant spring flowering bulbs, keep in mind that it is all about the soil temperature. The soil needs to be warm enough to allow the bulbs to establish roots before the ground freezes. The roots will help ensure that the bulbs won’t be pushed out of the ground by the freezing and thawing cycle Planting too early, when the soil is too warm will prompt the bulb to grow top growth, instead of the essential roots. Experts advise that bulbs need to be planted at least six weeks before the ground freezes and the ground temperature needs to be cooled to about 55 degrees Fahrenheit. But, without a crystal ball, how do you know when that is? Short answer: September or October is (usually) appropriate.

Spring Tulips - Denver Botanic Garden

Spring Tulips - Denver Botanic Garden

Have you ever wondered what the secret is to flower beds where something is blooming from early spring through mid-summer? The secret is a bulb planting technique called layering. It’s not difficult, and can be done effectively in any size garden, including a container. As the old saying goes - “ a picture is worth a thousand words”, below is a chart to help demonstrate this technique.


Remember that the experts at your local independent garden center can answer any questions you might have about how to plant your garden using the layering method.

There are many reasons to love spring blooming bulbs. First of all, the planting (work, if you call it that) is done in the fall when daytime temperature are cool and comfortable. Secondly, the burst of early spring color can beat back the winter doldrums . Also, bulbs are known as ‘drought evaders’ being as they are normally dormant during drought conditions. Bulbs bloom seemingly effortlessly, before the hot dry summer sets in, and the soil drys out! Lastly, many bulbs will naturally self propagate through the formation of offsets, bulbils, or seeds.

What are your favorite spring flowering bulbs?

Allison Gault