When you’re planting bulbs this fall for spring color, consider the trees. Certain bulbs make better companions for trees than others, according to Doris Taylor, Plant Clinic manager at The Morton Arboretum.
Keep the big, brassy tulips and hyacinths out in full sun, away from the shade of a tree’s branches. What you need beneath a tree is a perennial plant that is relatively shade-tolerant and blooms early, before the tree unfolds all its leaves. That gives each bulb plant time to get enough sunlight to recharge for next year before the deep shade comes.
Perennial bulbs don’t need to be replanted each year, and some will spread or even reseed if the conditions are right. That means that the tree’s roots will be disturbed only once, when you first plant.
It’s best if the bulbs themselves are small, so you can make a small hole to minimize the damage.
“The smaller the holes the better,” Taylor says.
Try a dibble–a pointed tool that makes a just-wide-enough hole.
Most of these bulbs have small flowers, so they need to be planted in groups of at least 30 to 50 to have much of a visual impact.
It’s easy to plant bulbs. The soil must be cool, so wait until after the first frost. Place the pointy end up (that’s the stem end). Dig a hole just three times as deep as the bulb is wide—so a one-inch-wide bulb needs a hole 3 inches deep. There’s no need to add fertilizer. Refill the hole, water the planted bulbs well, and spread mulch over the soil surface to insulate the soil and keep the bulbs from sprouting too early in a winter warm spell.
Shop dozens of bulbs for planting this season at The Arboretum's Annual Bulb Sale, going on now.
Here are four bulbs that are good companions for trees.