Bright and colorful blooms are one of the first signs that spring has finally arrived. Spring flowers, like tulips and daffodils, remind us that winter is over (for now!) and that life can still be beautiful even after months of harsh weather and piles of snow.
We can dream about spring flowers, but first we have to plant the bulbs that those flowers come from! As fall leaves fall and other signs of nature take over, the soil has started to cool down, which means you should start planting your spring bulbs.
Here are some tips and tricks that will help your spring garden be full of bright flowers in late April and early May:
Daffodils, tulips, hyacinths, snowdrops, crocus and alliums are just a few of the bulbs you can plant. Do not buy bulbs that are soft and mushy. Instead, pick ones that are full and firm. Bigger bulbs are also better because that typically means they will bloom even more!.
You should plant your bulbs after the first frost, but also before the ground freezes. At the Garden, we typically start planting bulbs within the first few weeks of October. As a general rule, bulbs of tulips and daffodils should be planted in September or October.
Most greenhouses, nurseries and big box stores sell spring-blooming bulbs in the fall. You can also order from your favorite mail-order catalog. Our preferred places to order bulbs from include Brent & Becky’s Bulbs and Colorblends®. If you purchase through Brent & Becky’s Bulbs, a port of every dollar you spend supports the Garden!.
Before you plant your spring bulbs, you should get rid of any annual plants and cut back any perennials that are there. These steps will not only make planting easier, but they will also keep debris from getting in the way of bulb foliage growth and taking away from your beautiful spring display. Also, make sure the bulbs can grow in well-drained soil that gets at least six hours of direct sunlight every day when they start to grow in the spring.
You should plant bulbs 2-3 times deep as they are wide. For example, a 2-inch bulb should be planted 6 inches deep. Plant your bulbs root side down, which means the pointy side should be on top. This way, all of them will come up from the ground and bloom at the same time. If you plant bulbs backwards or sideways, they will still get to the top of the soil, it might just take a little longer.
Similar to most other plants, bulbs need well-drained soil that is rich in organic matter. Therefore, mix compost into your bulbs’ planting holes to ensure the bulbs have the best conditions for blooming.
After you put your bulbs in the ground, make sure to water them once to get rid of any air pockets and help the soil stick to the bulbs. Although you won’t see any foliage or flowers until springtime, bulbs establish their roots in the fall.
To keep weeds from growing, you might also want to cover the soil where your bulbs are planted with two to three inches of mulch. This way, your bulbs will easily be able to grow through the mulch, but most weeds won’t.
We sprinkle Milorganite® on bulb display beds to help deter critters. For critter-attracting bulbs (mostly tulips) we also spray Liquid Fence® on a weekly basis, until the ground freezes. Once bulb foliage emerges in the spring, we continue our spraying regime until the bulbs are finished blooming.
Don’t like the idea of using Liquid Fence®? Opt for critter resistant bulbs like daffodils and alliums. Or better yet, come to the Garden and enjoy all of our tulips next spring!.
Wisconsin’s cold winters and fickle spring weather can make it tricky to determine the best time to plant spring-blooming bulbs like tulips, daffodils and hyacinths. Plant too early when soil temperatures are still warm and bulbs may start sprouting before winter. Plant too late and the ground may freeze before roots can properly establish. Follow this guide to identify that sweet spot in fall when bulbs have the best shot at thriving through winter and bursting into bloom next spring.
How Cold is Cold Enough?
Spring bulbs need to be planted in autumn once temperatures have cooled but before the ground freezes. Cool soil temperatures signal to bulbs that winter is coming and prevent premature growth. Experts recommend planting bulbs when soil temps reach an average of 55°F or below.
In southeastern Wisconsin this ideal planting window typically occurs in October following the warm spell known as “Indian Summer” when daytime highs are around 60-70°F. Nighttime temperatures in the 40s-50s°F during October are cold enough to keep bulbs dormant after planting.
Don’t Rely on the Calendar Alone
While October is a good ballpark target, basing planting time on calendar dates alone can be risky in Wisconsin. An early cold snap in September or a warm fall extending into November can shift the optimal planting window.
The most reliable gauge is to track local soil temperatures at bulb planting depth. Place a thermometer about 6 inches deep in the garden and monitor temperatures over late summer and fall. Plant bulbs once that soil thermometer consistently registers 55°F or below.
Allow Enough Time Before the Ground Freezes
Ideally, bulbs need 6-8 weeks after planting to establish roots before the ground freezes solid. This ensures the bulbs have the necessary energy stores to survive winter and bloom vigorously in spring.
If bulbs haven’t rooted before the ground freezes, they may heave up from the soil over winter. Wait too long and the bulbs won’t have enough time to root properly. In southern Wisconsin, soil usually freezes solid by early to mid-December. So for most of the state, bulb planting needs to happen by late October or very early November at the latest.
Tips for an Ideal Fall Planting Time
Follow these tips to determine the perfect fall planting time for your bulbs:
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Track your area’s average first freeze date and count backwards 6-8 weeks. This is the drop-dead deadline for bulb planting.
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Monitor soil temperatures at bulb depth starting in September, watching for sustained temps around 55°F.
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Allow about 4-6 weeks between planting and ground freeze for roots to establish.
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Plan bulb shipments and garden prep to be ready once the soil hits optimal temperature.
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If an early freeze threatens, temporarily protect planted bulbs with mulch.
Be Patient – the Payoff is Worth it!
It takes some patience and tracking to determine the ideal planting moment for bulbs, but the reward of seeing those vibrant flowers burst forth in spring makes the effort worthwhile. Just be vigilant about soil temperatures, allow adequate rooting time before a freeze, and your bulbs will thrive in Wisconsin’s challenging climate.
Planting Hardy Fall Bulbs – Wisconsin Garden Video Blog 735
FAQ
What month should you plant flower bulbs?
Do bulbs need soaking before planting?
Is it better to plant bulbs in fall or spring?
What is the general rule for planting bulbs?
Is gardening easy in Wisconsin?
Gardening in Wisconsin is easy so long as you have the right plan for spring and fall. In this guide, we’ll walk you through which plants thrive in Wisconsin, when to plant in Wisconsin, and how to adapt your garden as the seasons change.
How can I extend the life of my Fall Garden in Wisconsin?
You can also extend the life of your fall garden in Wisconsin zones 3, 4 and 5 by using methods such as hotbeds, covering plants with a plastic sheet at night, or “overwintering” perennials such as tomatoes and peppers. Still not sure what to plant in Wisconsin?
When to plant Iris?
Plant iris from early spring through midsummer. The later you plant, the less likely they will bloom in the current year. Plant tender, summer-flowering bulbs such as gladiolus, canna, dahlia and tuberous begonia in mid- to late spring, after all danger of frost has past.
How do I get the most out of my Garden in Wisconsin?
To get the most out of your garden in Wisconsin zones 3, 4 and 5, seedlings should to be started indoors. We also recommend using a blanket of straw to help protect transplants from a surprise frost. With so much of the growing season experiencing cooler temperatures, focusing on frost tolerant crops is a great strategy for success.