How To: Trench Planting Spring Blooming Bulbs

1. Choose bulbs for your zone

Tulips, Daffodils, and Mini Iris are among the most cold-hardy bulbs, and are typically cold hardy in zones 3-7. These bulbs require a dormancy period provided by the cold temperatures of winter.

If you’re in a warmer area, zones 8-10, choose Allium, Crown Imperial (Fritillaria), Wand Flower (Ixia) or Spider Lily (Lycoris).

2. Plant for non-stop blooms

Choose a variety of bulbs to make sure you have early-spring, mid-spring, late-spring blooms. Or, choose a fall bulb mix or collection - these are generally designed to bloom throughout the season.

• Early Spring-Blooming Bulbs include Crocus, Mini Iris and Wildflower Tulips. Crocus, Spring Starflowers, and Snowdrops pop through the snow in early spring.
• Mid Spring Blooming Bulbs include Grape Hyacinth (Muscari), Hyacinth, Darwin Tulips and Daffodils.
• Allium are perfect for Late Spring Blooms.

3. Plant bulbs where you can appreciate them

If you’re using small bulbs, be sure to place them near a walkway so that you can appreciate their delicate blooms. Use larger, bolder-blooming bulbs if the planting will be viewed from a distance.

4. Make sure you have enough bulbs

Based on the garden area, you’ll want to plant bulbs at the right density per square foot, depending on bulb size. Find the recommended bulb spacing on each product page, as well as on the bulb packaging.

• Smaller bulbs, such as Crocus, Grape Hyacinth (Muscari), and small blooming Allium, are around 16 bulbs per square foot.
• For larger bulbs, such as Tulips, Daffodils, and Hyacinth, typically 6 bulbs are planted per square foot.
• Some large bulbs--Globe Master Allium and Crown Imperial (Fritillaria) for example--are planted with as few as 3 bubs per square foot.

5. Make planting easy

For simple planting, choose bulbs that have the require the same planting density and planting depth. One easy way to do that is to plant a mix of the same bulb varietiy. Mini bulbs, including Crocus, mini Daffodils, Grape Hyacinth (Muscari), and Mini Iris also pair well, as most are planted with 16 bulbs per square foot and 2-4” inches deep.

6. Include some perennial bulbs

If you choose spring-blooming bulbs that naturalize, it means they are perennial bulbs that will multiply and spread. You’ll plant these bulbs just once, and enjoy them more year after year. Good naturalizers include Glory of the Snow (Chionodoxa), Grape Hyacinth (Muscari), Daffodils, and Wildflower Tulips. To ensure reblooming, fertilize after blooming each year with a 3-5-3 fertilizer.

7. Choose pest-resistant bulbs

If you have deer or other pests such as squirrels and voles, choose critter-resistant bulb varieties such as Daffodils, Grape Hyacinth (Muscari), Fritillaria, and Hyacinth. Planting strong-smelling Fritillaria amongst Tulips will often deter pests from Tulip bulbs, which are not pest resistant. (Note: Wildflower Tulips are deer resistant!)

8. Make a statement with a monochromatic blooms

People will notice your bulb planting from hundreds of yards away if you stick to one color. You can accomplish this in several ways. Try planting all Daffodils, but choosing varieties that will bloom at different times. Or, create a pleasing purple palette by choosing purple Crocus and Mini Iris for early blooms, Tulips, Grape Hyacinth and Hyacinth for mid-season blooms, and Allium for late season flowers.

9. Plant bulbs in layers for a “bursting with blooms” look

You can mix bulbs that require different depths. Dig the depth of the trench to the needs of the deepest bulbs (12” for large Daffodils). Plant those that need the greatest depth first. Add a few inches of soil and add another layer of bulbs that have shallower planting depths.

10. Plant spring-blooming bulbs in your lawn

Remove the sod before trench planting, then lay it over the planted area again. Make sure to account for the depth of the sod when digging your trench. Bulbs will poke through the lawn and bloom in spring-time. After your bulbs have gone dormant (a few weeks after blooming), you can resume mowing the area again.

11. Mix bulbs with perennials

You can also plant perennials on top of the bulbs, to disguise the bulb foliage as it dies back. Spring-blooming groundcovers such as Phlox, Veronica and Thyme work particularly well, as they will bloom in tandem with the bulbs. We recommend Veronica with Daffodils, Tulips with Thyme, and Phlox with Hyacinth and Allium. Learn More: Colorful Combinations - Mixing Perennials and Spring Blooming Bulbs