How Many Tulip Bulbs Per Square Foot? Spacing, Depth and When to Plant

A mesh bag of 50 tulip bulbs is sitting on the porch, and the bed along the front walk is 3 by 10 feet. Iowa State University Extension says to space large tulips 4 to 6 inches apart and plant them 6 to 8 inches deep. Bulbs per square foot = 144 ÷ (spacing in inches)², so that is 4 bulbs at 6 inches and 9 at 4 inches. Your 50 bulbs fill about 12.5 sq ft at 6 inches, and the whole 30 sq ft bed takes 120.

Quick pick: a long-handle bulb planter, so you can cut 6-inch-deep holes standing up.

Free calculator: for staggered rows and other plants, try the plant spacing tool in our free calculator.

Tulip bulbs per square foot by spacing

Bed counts use a square grid: (width in inches ÷ spacing) × (length in inches ÷ spacing), each rounded down.

6 in apart: 4 per sq ft. 3 × 10 ft bed: 120. 4 × 8 ft bed: 128.

5 in apart: about 5.8 per sq ft. 3 × 10 bed: 168. 4 × 8 bed: 171.

4 in apart: 9 per sq ft. 3 × 10 bed: 270. 4 × 8 bed: 288.

3 in apart (small species tulips): 16 per sq ft. 3 × 10 bed: 480. 4 × 8 bed: 512.

Iowa State gives 3 to 4 inches for small types like Kaufmanniana and Greigii. Clemson Extension gives 4 to 6 inches for standard tulips.

How many to plant together

Iowa State says to plant at least 5 of the same large variety in one spot, and groups of 10 or more look best. Small types look best in drifts of 50 or more.

A group of 10 at 5 in: about 1.7 sq ft

A drift of 50 small tulips at 3 in: about 3.1 sq ft

Buying for a bed: sq ft × bulbs per sq ft. A 3 × 6 ft strip at 6 in: 72 bulbs.

How deep to plant tulip bulbs

Large tulips: 6 to 8 inches deep (Iowa State, Clemson). Clemson measures depth from the base of the bulb.

Small species tulips: 3 to 5 inches deep (Iowa State).

Soil: Iowa State says tulips need well-drained soil, wet soil often causes rot, and poor soil should be amended with compost first. See how much compost you need.

Garlic in the same bed? It goes in much shallower. See how many garlic cloves per square foot.

When to plant tulip bulbs

Upper Midwest: Iowa State says October is ideal and planting is fine into late November or early December if the ground isn't frozen. September can be too early; leaves may come up in fall.

Warmer South: Clemson says to wait until the soil at planting depth stays below 60°F. In central and coastal South Carolina, it says to refrigerate bulbs from purchase until planting in November to late December.

Until then: store bulbs cool and dry, like a garage or basement (Iowa State).

After planting

☐ Cover the bed with 2 to 3 inches of mulch (Clemson). See winter mulch for perennials.

☐ In spring, leave the leaves until they turn brown. Iowa State says removing them early often reduces next spring's flowers.

☐ Plan to replant. Iowa State says most modern tulips bloom well for only 3 or 4 years, and Clemson says in South Carolina they are usually grown for one season.

Bulb planting tools (#ad)

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Haliaeetus Long Handle Bulb Planter, 37 in Stainless Steel: step and twist while standing. The maker says the cutting cylinder is 6 inches from the bottom edge to the top, with a 1 to 4 inch scale; check 8-inch holes with a ruler. See it on Amazon

K-Brands Auger Drill Bit for Planting, 2 Pack: 1.6 × 16 in and 3.5 × 16 in bits that fit a 3/8 in hex drill, per the maker. Iowa State says a drill and bulb auger make planting easier. See it on Amazon

Tulip bulb FAQ

How many tulip bulbs per square foot?

4 at 6 inches apart, about 6 at 5 inches, 9 at 4 inches.

How deep do you plant tulip bulbs?

6 to 8 inches for large tulips, 3 to 5 for small species types (Iowa State).

How many tulip bulbs should I plant together?

At least 5 of one variety; 10 or more looks best, Iowa State says.

When is it too late to plant tulips?

Once the ground freezes. Iowa State says late November or early December can still work.

Watch Curb Calc on YouTube: youtube.com/@curbcalc

Sources: Iowa State University Extension and Outreach, Richard Jauron, Paula Flynn and Aaron Steil, All About Tulips; Iowa State University Extension and Outreach, When is the best time to plant tulips?; Clemson Cooperative Extension Home & Garden Information Center, Spring-Flowering Bulbs, updated November 14, 2023.