When to plant bulbs
Spring-flowering bulbs: tulips, daffodils, crocus, hyacinth and more
The short answer
Plant spring-flowering bulbs in the fall, once the soil has cooled (state extension services give about 50-55°F up to below 60°F), early enough for roots to grow before the ground freezes. Minnesota, Colorado and Iowa give mid-September to October; South Carolina gives October to November, and later on the coast. Spring-planted spring bulbs usually do not grow well.
Fall planting rules by region
These are published by the extension service of each state. They differ because autumn arrives at different times; look up your own first fall frost and use the nearest region as a guide.
| Minnesota | Usually mid-September to mid-October, so roots grow before the ground freezes. Tulips can go in as late as you can get them into the soil. (University of Minnesota Extension) |
| Colorado | Late September is preferred and September and October are the best months. Bulbs planted after October may not root well enough to flower evenly in spring. (Colorado State University Extension) |
| Iowa | October is ideal. September can make tulips send up leaves in fall. Procrastinators can plant as late as December if the ground is not frozen. (Iowa State University Extension) |
| Wisconsin | Plant when the ground cools to about 50-55°F or lower (but is not frozen), and keep planting until a couple of weeks before the ground freezes. (University of Wisconsin Extension) |
| South Carolina | Daffodils in October or November. Other spring bulbs only once the soil at planting depth stays below 60°F. On the coast, most bulbs go in late December or early January. (Clemson Home & Garden Information Center) |
| North Carolina | Plant in fall to build roots and meet the cold requirement, which ranges from six to 20 weeks depending on species or cultivar. Wait until the soil at planting depth is below 60°F. (NC State Extension) |
| Missouri | Spring-blooming bulbs should be planted in October so they go through a cooling process over the winter. Daffodils are the best choice for Missouri because they handle the warmer temperatures and keep blooming year after year. Tulips will likely need to be replanted every couple of years. Hyacinths adapt worst: temperatures rise too quickly in spring for the bulbs to store food, so they tend to decline after the first year. (University of Missouri Extension) |
| Georgia | Spring-flowering bulbs can be planted from October through late December in most areas. (University of Georgia Extension) |
| Michigan | Many Michigan nurseries recommend a cutoff of late October for getting bulbs into the ground, because planting recommendations depend mainly on soil temperature. For bulbs that miss it, MSU Extension suggests a sheltered spot, a thicker mulch, or refrigerator chilling (for most bulbs, 14-16 weeks below 45°F). (Michigan State University Extension) |
In South Carolina, Clemson adds that most bulbs need a 12- to 16-week chilling period, and that bulbs which get too little chilling bloom close to the ground on very short stems. Coastal gardeners there can refrigerate bulbs in ventilated packages until planting.
Planting depth and spacing chart
| Bulb | Depth (inches) | Spacing (inches) |
|---|---|---|
| Tulip (Darwin hybrid, triumph) | 6-8 | 4-6 |
| Tulip (species or botanical) | 3-5 | 3-4 |
| Daffodil (trumpet, large-cupped) | 6-8 | 6-8 |
| Daffodil (miniature) | 3-5 | 4-6 |
| Hyacinth | 6 | 6-8 |
| Crocus | 3-4 | 3 |
| Allium (large, e.g. giganteum) | 6 | 12-18 |
| Allium (small, e.g. moly) | 3-5 | 6-8 |
| Grape hyacinth (Muscari) | 3-4 | 3-4 |
| Snowdrop | 3-4 | 3 |
| Siberian squill (Scilla) | 3-4 | 3 |
| Striped squill | 3-4 | 3 |
| Glory-of-the-snow | 3-4 | 3 |
| Spring snowflake | 3-4 | 3-4 |
| Spanish bluebell | 4 | 4-6 |
| Camassia | 4 | 4 |
| Fritillaria (crown imperial) | 6-8 | 12-18 |
| Fritillaria (checkered lily) | 3-4 | 4 |
From Iowa State Extension; depth is measured from the base of the bulb to the soil surface, pointed end up. Minnesota adds: 1-2 inches deeper in light sandy soil, 1-2 inches shallower in heavy clay. NC State uses a slightly deeper rule, 2½ to 3 times the bulb's diameter (most small bulbs 5 inches, large bulbs 8 inches), counting the 2-3 inch layer of mulch it recommends as part of that depth.
Guides for each bulb
Questions gardeners ask
When is the best time to plant spring bulbs?
In the fall, once the soil has cooled and at least a couple of weeks before it freezes. Wisconsin Extension gives soil around 50-55°F or lower; Clemson says below 60°F at planting depth. In cold states that is mid-September to October.
Is it too late to plant bulbs?
Not while the ground can still be dug. Iowa State says bulbs can go in as late as December if the ground is unfrozen, and Minnesota says tulips can be planted as late as you can get them into the soil. Colorado warns that bulbs planted after October may not root well enough to flower evenly.
Can you plant spring bulbs in spring?
Iowa State says no: spring-planted spring bulbs usually do not grow well because they lack a developed root system, and they need a cold period to bloom.
How deep do you plant bulbs?
Two to three times the bulb’s diameter, which Iowa State turns into about 6-8 inches for tulips, daffodils and hyacinths and 3-4 inches for small bulbs such as crocus. Add an inch or two in light sandy soil and use an inch or two less in heavy clay (Minnesota).
Page 5 is this bulb guide with the regional rules and depth chart on one printable page, plus zone dates and logs for the rest of the garden.
Free to print for personal use.
Sources
- University of Minnesota Extension: Planting bulbs, tubers and rhizomes
- Colorado State University Extension: Fall-Planted Bulbs and Corms
- Iowa State University Extension: Selecting and Planting Spring-Blooming Bulbs
- University of Wisconsin Extension: Plant Bulbs Now for Spring Color
- Clemson Home & Garden Information Center: Spring-Flowering Bulbs (HGIC 1155)
- NC State Extension: Extension Gardener Handbook: Herbaceous Ornamentals
- University of Missouri Extension: Countdown to beautiful spring flowers begins now
- University of Georgia Extension: Flowering Bulbs for Georgia Gardens
- Michigan State University Extension: Is it too late to plant bulbs?