Our complete guide to planting flower bulbs

It's full autumn, the annuals are nearing their end, and the leaves are falling from the trees. Autumn is the perfect time to plant flower bulbs in the garden. Flower bulbs are a delightful and rewarding addition to any garden: they bloom spectacularly in early spring, quickly making the cold and harsh winter months a distant memory. The first bloomers also provide much-needed food for the insects that awaken first.

When can flower bulbs be planted?

Bulbs should always be planted in the autumn, from the end of September to the end of December. They need a cold period to awaken. Always pay attention to the quality of the bulb when planting:

Are the bulbs firm? Bulbs should not be soft or moldy.
Is the bulb intact?
Are there no spots on the skin?

When in doubt, discard the bulb to avoid further contamination. Most bulbs can be planted with confidence during these months, except for tulips. Tulip bulbs are very sensitive to tulip fire or Botrytis Tulipae. Tulip fire is a fungus that affects the bulbs, causing spots on the leaves and tulip flowers, which may result in poor or no blooming. So, wait a bit before planting tulips in the ground or pot, preferably until the end of October - ideally early November. The bulbs can be planted any day, as long as the soil is workable.

Spring bulbs and their bloom times

Not every bulb blooms at the same time. So, be sure to add a variety of bloom times to the garden for as many flowers as possible.

Early bloomers, such as crocuses and snowdrops.

Afterwards, the mid-season bloomers appear. These include daffodils and hyacinths.

Finally, the late bloomers flourish: these are the tulips and the Alliums.

Learn more through our videos

Did you know we also have a well-stocked YouTube channel? With more than 450 videos, we have a large database of information. Be sure to check out YouTube and subscribe to stay updated with the latest videos.

In this video, Angelo teaches you how to create a bulb lasagna. On small surfaces, you can have an explosion of bulbs in the spring.

Making a bulb lasagna

Do you have limited space in the garden or want to brighten up some pots with bulbs? Then a bulb lasagna is the perfect addition. By planting the bulbs in layers, you can enjoy various types of flowers in a very small area. It's important to maintain the correct order so that all the bulbs have the chance to grow sufficiently.

Choose a beautiful pot with a hole at the bottom and cover the hole with a shard of pottery or hydro granules. This allows excess water to drain from the pot, preventing the bulbs from rotting. Always plant the bulbs with the tip facing up and place about five centimeters of peat-free potting soil between each layer of bulbs.

Start at the bottom of the pot with the latest blooming bulbs, such as tulips and Alliums.

Daffodils form the middle layer of the pot.

Finally, finish with the earliest blooming bulbs, like crocuses.

Finish the bulb lasagna with a layer of mulch, such as wood chips. However, if you want a colorful display to enjoy all winter, plant violas on top of the bulb lasagna. Don't worry, the bulbs will grow effortlessly through them.

What about the soil?

Bulbs don't like wet feet. It's best to plant them in well-draining soil, so water doesn't linger around the bulbs. If you have heavy soil, like clay, improve it with compost or add a handful of sand or small stones to the planting hole when planting the bulbs. This allows excess water to drain away during rainfall.

Always plant bulbs completely underground. A handy rule of thumb is to plant the bulb at a depth of about 2 to 3 times the size of the bulb. This ensures the bulb is stable and won't topple over during blooming. Use a bulb planter or a hori hori knife to make a planting hole. Even in open ground, plant the bulbs with the pointed end up to ensure smooth growth. Once all the bulbs are planted, it's best not to give them extra water. In autumn, there's usually enough rain, so additional watering isn't necessary.

What about planting distance?

One or two bulbs in an entire border won't have much effect. If you're planting bulbs in the border, aim for the wow effect. Group the bulbs so they have more visual impact. Place them in clusters of 7 to 9 bulbs per type and scatter them randomly in the border.

For large bulbs, keep about 10 to 15 centimeters of distance between them. This gives them enough space to naturalize and grow robustly. For smaller bulbs, like crocuses, the distance doesn't need to be as large. In this case, about 4 to 6 centimeters is sufficient.

Flower bulbs can also naturalize over time. Certain bulbs, known as stinzen bulbs, return year after year in the border and multiply. Not every bulb will naturalize or reappear the following year in the garden. Regular tulips give their best show the first year, but bloom less exuberantly or not at all the next year. So, choose wisely where you plant each type, and you can enjoy a floral spectacle every early spring. Here's a brief overview of some types that naturalize: