Planting Tulips WITHOUT Digging? Cornell Study Surprises

By Linda Lee

Here’s an unusual tip for planting tulips this fall: don’t dig bulbs at all. This method, known as “Till and Fill,” challenges the usual advice to dig bulbs 6 or 7 inches deep. Instead, just plant them two inches deep.

You might be skeptical, but the Cornell Flower Bulb Research Program identified this approach over a decade ago, although it hasn’t widely circulated.

Method No. 1: The Annual Tulip Bed

Try creating your tulip bed like the annual displays at Keukenhof in Holland or on Park Avenue. Prepare a bed in your yard by loosening the soil with a rototiller or garden fork to just a couple of inches deep.

Place the tulip bulbs on the soil surface in close rows, similar to an egg crate, leaving about half an inch between each bulb. This technique is called “top planting.” William B. Miller, a horticulture professor and director of Cornell’s Flower Bulb Research Program, announced the discovery in 2011 as a “toil-free” way to plant tulips and endorsed it as “a good way to go.” His research confirmed its effectiveness.

In this method, 100 bulbs fit in a small area roughly two by six feet. Since it’s an annual planting, fertilizing is unnecessary.

Next, cover with mulch. Your local municipality may offer free mulch made from shredded trees, twigs, and bark, or you can use straw or chopped leaves. Apply a mulch layer about four inches thick. Water if the soil is dry. That’s all there is to it.

This “Till and Fill” approach requires no digging at all. After blooming, simply rake up the tulips and mulch to clear the bed.

Similar to Keukenhof and Park Avenue, these bulbs last one season only. (Keukenhof mulches them; Park Avenue donates them afterward.) Don’t wait for the leaves to die back before removing the bulbs. Once the tulips are cleared, the bed is perfect for planting tomatoes, dahlias, or mixed summer flowers.

Method No. 2: The Perennial Tulip Bed

Bill Miller returned in 2019 via a Cornell Flower Bulb Research Program newsletter advising minimal digging to encourage tulips to come back year after year. He recommends against planting tulips 6 to 8 inches deep, saying, “Shallower planting should generally be advised.”

Cornell’s test beds demonstrated that planting tulips as shallow as two inches, covering them with soil, then mulching—even in Cornell’s zone 5b climate—produces the best perennial blooms over three years. Here’s how:

Dig a bed just two inches deep. In the fall, use a rototiller or garden fork to loosen the soil. Lightly apply BulbTone 3-5-3 fertilizer over the soil. Space the bulbs about four inches apart, then use a shovel to cover them with soil. Apply a mulch layer about four inches deep, possibly topping with shredded leaves or straw.

Miller’s research conclusively showed tulips planted deeply do not return as robustly each year compared to shallow planting—provided gardeners mulch deeply over the winter each year, not only the first year.

Regarding cost, bulk bags of 100 yellow Rotteveel Darwin tulips are available for about $42.56 on Amazon. Darwin tulips bloom mid-season and produce long, sturdy stems. Purchase the same variety to ensure synchronized blooming.

Darwins can also be found at Tulip World selling 25 bulbs for $7 to $10.

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