When to Plant Tulip and Daffodil Bulbs: The 60°F Soil Rule

If you want tulips and daffodils in April, you have to plant them in the fall, and most people either plant too early in a warm spell or forget until the ground is frozen. The good news is that the right moment is easy to spot once you know what to look for. Extension horticulturists use the same rule almost everywhere: plant when the soil has cooled and stays below about 60°F.

Why bulbs go in during fall

Tulips, daffodils, hyacinths, crocus and most other spring bulbs need a long cold spell before they'll flower. NC State Extension puts it at 12 to 16 weeks of chilling for most spring bulbs. Without enough cold, the flowers come up on short stems close to the ground, or don't bloom at all.

Planting in fall lets winter do the chilling for you. The bulbs also need a few weeks in cool soil to grow roots before the ground freezes, which is why "as late as possible" isn't the goal either.

The rule: soil below 60°F

The calendar is only a rough guide. The better signal is soil temperature that stays below about 60°F, measured near the depth the bulbs will sit, around six inches down. A cheap soil thermometer settles it in a few seconds.

Roughly, that works out to:

• Northern states and colder zones: late September to early October.
• Middle of the country (e.g. eastern Nebraska, the mid-Atlantic, the DC area): late September through October, often into early November.
• The Southeast (e.g. eastern North Carolina): November.
• The Deep South and other mild-winter areas: winters often aren't cold enough. Alabama Extension recommends buying pre-chilled tulip bulbs and planting them in mid to late December, and treating them as annuals.

If you don't have a thermometer, a run of cool nights is a reasonable stand-in. Some growers wait until nights stay in the 40s°F. Your state's Cooperative Extension office will know the usual window where you live.

How deep and how far apart

• Depth: plant about three to four times as deep as the bulb is wide, measured to the base of the bulb. For a standard tulip or daffodil that's usually 6 to 8 inches.
• Spacing: large bulbs 3 to 6 inches apart; small bulbs like crocus or grape hyacinth 1 to 2 inches apart. Groups of the same variety look fuller than single rows.
• Which way up: pointed tip up, flat root plate down. If you can't tell, plant it on its side; it will right itself.
• Water once after planting to settle the soil and get roots started.

Fertilizer won't change this spring's flowers, since the bulb already holds its food, but it helps them come back in later years. NC State suggests a slow-release fertilizer mixed in at planting, or a 10-10-10 at planting and again when the shoots appear. Get a soil test before adding bone meal or other phosphorus.

Storing bulbs until it's time

Bulbs often go on sale in September, before the soil is ready. Pick firm ones with no mold, soft spots or bruising, and keep them somewhere cool, dry and dark with air around them, such as a paper bag in the garage. Keep them away from ripening fruit, which gives off ethylene and can damage the flower inside.

This is where most bulbs go wrong: they get bought, put in the garage, and found again in February. If you're buying early, set the planting date at the same moment you buy them.

Common questions

Is it too late to plant bulbs in November or December? Often not. If you can still dig the ground, plant them. Late bulbs may bloom a little later or shorter, but bulbs planted late do better than bulbs left in a bag over winter.

Can I plant bulbs in October? In most of the US, yes. October is the main planting month for much of the country. Check that the soil has dropped below 60°F, especially after a warm spell.

Why do tulips only bloom once in the South? Mild winters don't give them enough cold to rebloom, so gardeners in warm areas treat them as annuals and replant pre-chilled bulbs each year. Daffodils usually come back more reliably.

Do squirrels eat bulbs? Squirrels and voles often dig up tulips and crocus but tend to leave daffodils alone. Covering a fresh planting with chicken wire until the ground freezes helps.

A simple timing plan

Bulb planting is a once-a-year job with a moving date, which is exactly the kind of thing that gets forgotten. Three reminders cover it:

1. Mid-September: order or buy bulbs while the choice is good.
2. Your local planting week: check the soil temperature, then plant. If it's still above 60°F, push the reminder back a week.
3. Early spring: when shoots appear, feed them and note which spots need more bulbs next fall.

With ReminderIt you set these up by chatting on WhatsApp: "Remind me on October 25 at 10am to check the soil and plant the tulip bulbs." At that time your phone rings and a voice reads the reminder, which is harder to swipe away than a notification, and a WhatsApp message arrives with Done and Snooze. If the soil is still too warm, just reply "move it to next Saturday". It works in most countries, there's no app to install, and there's a 7-day free trial with no card. After that it's $7 a month.

Message ReminderIt on WhatsApp at https://wa.me/14786061901 and set your bulb-planting reminder before the bag disappears into the garage.