Nothing in the late-winter garden excites me more than the sight of the first crocus pushing its way tenaciously through redwood mulch like a newly hatched chick.  About mid-February I check the garden daily looking for that first brave yellow bud to burst into bloom announcing the advent of spring.  From then on until mid-June, I am constantly delighted and surprised by the colorful procession of blooms unfolding like a perfectly choreographed parade across the berm in my front yard.   It is then that I cash in on the reward for those hours spent digging and setting bulbs in early October.

Spring flowering bulbs are hardy adaptable plants-miniature powerhouses of energy that crank out flowers year after year with a minimum of care and handling. Crocuses, snowdrops, miniature irises, daffodils, hyacinths, tulips, Dutch irises, bearded irises, and alliums are just a few of the hundreds of choices hardy to zones 4 and 5 along the Front Range.  All these tenacious subterranean organisms ask of the gardener is to be planted well before the first hard freeze (late September to mid-October) and to be given adequate drainage, sunlight, water, and some fertilizer.  They also prefer to be tucked away for the winter under a three-inch blanket of mulch where they will benefit from the cold weather without suffering from the damaging effects of alternate freezing and thawing.

Many variables come into play as you design the layout of spring bulbs in your garden.  The three most important to consider are color, height, and flowering time.   Flowering time will vary somewhat depending upon the orientation and altitude of your garden and the planting depth.   With all these factors in mind, let your creative side take over to choreograph patterns of bulbs that will both delight and surprise you.  Arrange them in groups-six or more bulbs per cluster-for a more dramatic effect and position the shorter ones in front and taller varieties to the back or middle of the garden.

Here are just a few of the spring flowering bulbs that thrive in the Colorado garden and can be expected to reappear year after year with proper planting and maintenance:

Very Early Spring Blooms (late February/early March)--snowdrops (Galanthus), crocuses (Crocus chrysanthus 'Advance')

Early Spring Blooms (March)--dwarf irises (Iris reticulata 'Harmony' and Iris danfordia), crocuses, daffodils (Daffodil obvallaris), tulips (cardinal red, Kaufmanniana). grape hyacinths (Muscari).

Mid-Spring Blooms (Mid- March/April)--tulips, grape hyacinths (Muscari),  hyacinths, and countless varieties of daffodils and narcissus

Late-Spring Blooms (May/Mid-June)--tulips, Dutch irises, alliums, and bearded irises.

Bulbs are planted deeper than seeds and prefer a sandy or clay loam soil.  Along the Front Range, soils are often heavy in clay and will have to be amended with organic matter-compost or peat moss-before planting to insure adequate drainage.   Remember that you'll be setting your bulbs four to ten inches below the surface of the soil depending upon the size and type of the bulb so it is important to amend deeply, raking and turning the soil several times as you incorporate your choice of organic matter.  The easiest way to plant a lot of bulbs at once is to dig a large burial pit to the required depth  (generally four times the height of the bulb) and arrange them in a mass planting being sure to allow the proper distance between each bulb.

For more information on spring bulbs see Gardening Fact Sheets #7.410 Fall-Planted Bulbs and Corms.

Also from Plantalk Colorado are #1006 alliums; #1007 Bulbs: Bed Preparation; #1010 Bulbs: Maintaining;  #1011 Bulbs: Selecting; #1012 Bulbs: Spring Flowering; #1038 Bulbs: Fertilizing.

Planttalk Colorado^TM is a 24-hour toll-free automated phone service that provides you with reliable, timely information on a variety of horticultural topics. Toll Free Number: 888-666-3063.
The Web site has text versions of all the Planttalk Colorado® scripts.

Q:  Some neighbors are continuing to water trees and shrubs and even their lawns this late in the fall.  Is this really necessary?

A:   It is important to continue to provide moisture into the fall because plants are storing nutrients to get through the winter.  Remember that as long as the ground is not frozen plants continue to take up water and nutrients from the soil.  If the fall has been dry, it is wise to provide additional moisture, especially for newly planted trees, shrubs and perennials.  If the winter is lacking snow cover, continue to water once a month when temperatures are above freezing.

Q:  Can I still plant tulips and other spring flowering bulbs into November?

A:  Of course as long as the ground is not frozen!  Better get planting, though.  All fall planted bulbs need a few weeks of relatively warm soil to establish root systems.  After the ground freezes, bulbs may be unable to develop a good root structure.  Apply a super phosphate fertilizer when planting and add 3 to 4 inches of organic mulch.

Q:  Speaking of mulching, it seems like it all just blows away anyway.  Is it really that important to mulch my trees, shrubs, perennials, and roses?

A:  You bet it is.  You might consult your CSU Cooperative Extension office or local nursery on mulch appropriate for your situation. Some mulches are more “permanent” than others.  But mulching is very important to keep the soil moist, stable, and to protect against constant freezing and thawing.  Roses, particularly hybrid tea roses, should be mulched very well in the late fall.  Mulch also helps to improve the soil texture as it breaks down. Never put black plastic under mulch in the landscape as it keeps water and oxygen from reaching the roots.

Give a sigh of relief as your Kentucky bluegrass turns back to green.  Kentucky blue is also known as 'resurrection grass' by some. As a normal part of its life cycle as a cool season grass, it starts out nice and green in the spring and early summer; it goes dormant and turns brown during the heat of July and August. It then greens up again as the temperatures cool off in the fall.

As the weather cools, it is a good time to visit your local nursery to purchase your favorite trees. The trees have the cooler fall weather and hopefully some moisture to begin establishing a root system before the ground freezes. Apply three to four inches of organic mulch to help retain moisture and moderate soil temperatures. Keep in mind that you do have to continue watering during dry fall and winter months.

Aerating your lawn in the fall is a good habit to get into. If you plan on overseeding, aerate the lawn first and create many holes close together.  This will provide a protected and moist environment for the new seeds to start germinating and protect them from hungry birds.

The authors have received training through Colorado State University Cooperative Extension's Master Gardener program and is a Master Gardener volunteer for Larimer County.

Gardening and Insect Fact Sheets are available on-line by clicking HERE.

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This page updated:  September 29, 2003