How and When to Plant Bulbs for Beautiful Blooms

Planting bulbs, no matter the season, is a wonderful garden project, as you know your plants will return and grow back year after year, making them a desirable addition to any yard or flower bed.

Knowing when each type of bulb is in bloom can also ensure your flower bed is flourishing each and every season.

This guide walks you through the different types of bulbs and when, where, and how to plant them. We also provide useful tips for spring bulb planting and for overwintering bulbs in climates with cold winters. 

Key Tips for Planting Bulbs

• Choose a location that gets at least six hours of full sun.
• The soil should be sandy, loamy, free of large rocks, and well-draining, with a pH in the neutral range.
• If you want to add organic matter to the soil, which is always beneficial, amend the entire planting area, not just the soil in individual planting holes.
• Avoid locations with poor drainage. Flower bulbs do not like getting their feet wet, as they will rot.
• Also avoid planting in locations along a road, walkway, or driveway where plowed snow with road salt or de-icing agents accumulates in the winter.
• Do not plant in locations with soil disease issues; flower bulbs are highly susceptible to soil-borne diseases.
  

How to Plant Bulbs

Although the underground parts of the plants don’t all look exactly like bulbs, the term "bulb" includes plants with true bulbs, corms, tuberous roots, and rhizomes.

After you have prepared the planting site, follow these steps:

1. For each bulb, dig a hole deep enough so that the bulb is planted at a depth of two to three times its height. Ideally, dig another 2 to 3 inches below the planting depth to loosen the soil, which promotes root growth.
2. Place the bulb in the hole with the pointed side up and the root side down.
3. Fill the planting hole with original soil and gently tamp it down.
4. Mark the planting spot or area with a sign that is not going to be dislodged by wind and weather, such as a decorative stone, plant tag, or other identifying system. Alternatively, draw a garden map to scale.
5. Spring-flowering plants often fall victim to hungry squirrels, chipmunks, and other rodents. To protect the bulbs, place a mat of chicken wire with 1-inch openings over the bulbs and cover it with soil. This will deter the critters from digging in the soil while bulb stems and foliage are allowed to grow through the openings.
6. Water the bulbs immediately after planting. This settles the soil, removes any air pockets, and gets the root growth started. Unless there is a drought, it is not necessary to water the bulbs after this initial watering.
   

All About "Lasagna Planting" Bulbs

Lasagna planting is an innovative way to plant different bulbs together in the same area in different layers. It maximizes garden space and provides a continuous array of flowers all spring. Here is how it works:

• The largest, latest flowering bulbs are planted as the bottom layer.
• After adding a layer of soil, mid-season flowering bulbs are planted in a middle layer.
• The early spring flowering bulbs are planted in the top layer closest to the surface. 

To learn more about lasagna planting, including which spring bulbs are suitable and when to start, follow these detailed instructions. 

Types of Bulbs

Many people associate flower bulbs mostly with spring-bloomers, such as tulips and daffodils, but in fact, there are many gorgeous summer-blooming and fall-blooming bulbs worth planting.

Knowing the differences between the bulb types is key not only for planting the bulbs at the right time but also for all other aspects of bulb care. 

Flowering bulbs fall into three main groups: 

Spring-Blooming Bulbs

Also called hardy bulbs, spring-blooming bulbs are very cold-tolerant, in fact, not only do they survive snowy, subzero winters in the ground, they need cold weather, referred to as the chilling period, to develop roots and form flowers in the spring.

The ideal chilling period for most spring-blooming bulbs ranges between 10 to 16 weeks at 35 to 45 degrees F.

In warm climates, winter temperatures do not meet the chilling requirements. But that does not mean you won’t be able to enjoy spring flowers, you just need to grow them as annuals and buy pre-chilled bulbs. 

Popular spring-blooming bulbs include:

• Allium
• Camassia
• Crown imperial (Fritillaria)
• Crocus
• Daffodil (Narcissus)
• Glory of the snow (Chionodoxa)
• Grape hyacinth (Muscari)
• Grecian windflower (Anemone blanda)
• Iris (bearded iris, Dutch iris, Siberian iris)
• Hyacinth
• Siberian squill (Scilla)
• Snowdrops (Galanthus nivalis)
• Tulip
• Winter aconite (Eranthis hyemalis) 

Summer-Blooming Bulbs

Bulbs that bloom in the summer are usually more tender. They are often native to warm climates and thus don’t survive cold, snowy winters like spring-blooming bulbs. In cooler climates, they are either grown as annuals or dug up, stored, and replanted every year (more about that below). 

Popular summer-blooming bulbs include:

• Asiatic lily
• Calla lily
• Canna
• Crocosmia
• Dahlia
• Gladiolus
• Elephant ears
• Pineapple lily
• Tuberose 

Fall-Blooming Bulbs

While some of the summer bulbs bloom into the fall, some bulbs bloom only in the fall. This group might be smaller, but it is mighty.

Unlike spring-flowering and summer-flowering bulbs, you’ll have more instant gratification—many of them flower the same fall when they are planted. Other types grow foliage in the spring, then go dormant over the summer, and emerge with flowers in the fall. 

Popular fall-blooming bulbs include:

• Autumn crocus
• Colchicum
• Gloriosa lily
• Rain lily 

When to Plant Bulbs

The timing for planting bulbs depends on the type of bulbs and your growing zone. To plant your bulbs at the right time, follow these guidelines. 

Spring-Blooming Bulbs

Spring-blooming bulbs are planted in the fall or early winter before the ground is frozen. Correct timing of planting is essential for success—if you plant them too early in the fall, you risk that the bulbs grow foliage too early, which depletes the energy they need to make it through the winter and bloom in spring.

• USDA Zones 2 to 4: Plant bulbs in late August or early September. This gives the bulbs enough time to establish some roots before the ground freezes.
• USDA Zones 5 to 7: Wait until the ground has cooled to at least 55 degrees F which typically happens after the first light fall frost, between the end of September and early November.
• USDA Zones 8 and higher: You will need to use pre-chilled bulbs because the winters are not cold enough for the bulbs to receive the chilling period they require. Check if the nursery of your choice sells pre-chilled bulbs. The bulbs are typically shipped for planting between mid-December and mid-January.
  

Summer-Blooming Bulbs

The tender summer-blooming bulbs are planted in the spring when there is no further danger of frost, the weather is consistently warm, and the soil temperature has reached at least 60 degrees F.

The following is only an approximate planting schedule, planting might be possible earlier or will have to be delayed depending on the weather.

• USDA Zones 8 and higher: Mid-March or sooner
• USDA Zone 7: April or early May
• USDA Zone 6: Mid- to late May
• USDA Zone 5: Around Memorial Day, depending on the weather.
• USDA Zones 3 and 4: June or earlier

Unless you live in a climate where the ground doesn’t freeze, you will have to replant tender perennial summer bulbs every spring.

Fall-Blooming Bulbs

The planting time of fall-blooming bulbs depends on the species. Follow the specific instructions for the type of flower you are planting. 

Fall-flowering crocus and colchicum are planted in the late summer or early fall when the heat of the summer has subsided. Depending on your climate, you can expect a bloom in 4 to 6 weeks. 

Gloriosa lily and rain lily, on the other hand, are planted in the spring. 

How to Dig Up Bulbs

Hardy bulbs such as tulips, daffodils, and lilies do not have to be dug up; they are cold-hardy and will die back in the fall but come back the next spring.

If your climate is too cold for tender summer-flowering bulbs such as cannas or dahlias, you can either grow them as annuals or dig them out every fall, store them indoors, and replant them the next spring.

The method of digging up the bulbs and overwintering them varies slightly depending on the type of plant. Check out the specific instructions for two of the most popular tender bulbs grown in cool climates, dahlias and cannas.