Planting Tulips WITHOUT Digging? Cornell Study Surprises

By Linda Lee

We’ve uncovered a little-known tip for planting tulips this fall: don’t dig holes at all. This technique is called “Till and Fill.” Instead of following traditional guidelines to dig bulbs 6 or 7 inches deep, simply dig holes two inches deep.

You might be thinking, huh? But the Cornell Flower Bulb Research Program discovered this over ten years ago, and somehow the information never spread widely.

Method No. 1: The Annual Tulip Bed

Think about creating a tulip bed like the annual displays at Keukenhof in Holland or Park Avenue. Clear a bed in your yard, then rototill it or use a garden fork to loosen the soil to a depth of just a couple of inches.

Place the tulip bulbs right on top of the soil in a tight arrangement—like an egg crate—with about half an inch spacing between bulbs. This technique is called “top planting.” William B. Miller, a former horticulture professor and director of Cornell’s Flower Bulb Research Program, presented the findings in 2011, labeling it “a good way to go.” His lab tests confirmed its effectiveness.

With this method, 100 bulbs cover a modest area of about two-by-six feet. Since this is a one-year setup, fertilizing isn’t necessary.

Next, apply mulch. Your local municipality might provide free mulch made from shredded branches, twigs, and bark. Alternatively, use straw, chopped leaves, or a mixture. Ensure the mulch layer is four inches thick. Water if the soil is dry. That’s it.

This “Till and Fill” method works without any digging. After the tulips bloom, rake the bulbs and mulch out of the bed.

Just like at Keukenhof and Park Avenue, these bulbs last for one season only. (Keukenhof mulches them; Park Avenue distributes them.) Don’t wait until the leaves wither—you can plant tomatoes, dahlias, or mixed summer flowers in the bed afterward.

Method No. 2: The Perennial Tulip Bed

Bill Miller returned in 2019 through a Cornell Flower Bulb Research Program newsletter to recommend minimal digging to ensure perennial blooms. He advises against planting tulips 6 or 8 inches deep, advocating that “shallower planting should generally be advised.”

Cornell’s test beds demonstrate that planting tulips as shallow as two inches, then covering with soil and mulching—even within Cornell’s 5b climate—produces the most plentiful tulip returns after three years. Here’s how:

Dig about two inches deep. In the fall, use a rototiller or garden fork to loosen the soil. Lightly apply BulbTone fertilizer (3-5-3) over the surface. Place bulbs about four inches apart, then fill the soil back in with a shovel. Apply mulch, topping with shredded leaves or straw, creating a four-inch deep mulch layer.

Miller’s Cornell studies clearly show tulips planted in deep holes don’t return as well year after year compared to those planted shallowly, provided the gardener mulches deeply every winter—not just the first year.

Cost-wise, you can find bulk bags of 100 yellow Rotteveel Darwin tulips on Amazon for around $42.56. Darwins bloom mid-season and feature tall, strong stems. Buy a single variety so they bloom simultaneously.

Darwin tulips are also available at Tulip World priced between $7 and $10 for 25 bulbs.

Linda Lee is a former writer and editor at The New York Times.