Size of a lily bulb
The optimal size of a lily bulb is different for each species, variety and hybrid.
For example, with Asiatic lilies, which have tall flower stalks with many flowers, it is generally the small lily bulbs that produce the most flowers. Large Asiatic lily bulbs also tend to develop into plants that are harder to transplant and adapt to (in some gardens).
With daffodils it's the other way around; the larger the bulb, the more flowers it produces.
Planting lily bulbs
Time of planting
When you buy your lily bulbs, they are already ready to be planted – in fact, you should plant them as soon as possible if you have bought them at the right time.
Most lily bulbs should be planted in:
- Spring – immediately after the frost has disappeared from the ground; this way you can have flowering lilies in summer/late summer. However, flowering may be slightly shorter compared to planting in the fall
- Autumn – before the ground freezes; this way you get the most reliable flowering in spring/summer
However, daffodil bulbs are an exception, as they should only be planted in the fall.
If you plant lilies in the spring, keep in mind that the following winter will “reset” the lily's flowering cycle – meaning they will start flowering in their normal rhythm again after winter.
Location
- All lilies can grow in partial shade and most can also grow in full sun
- However, some lilies thrive best in partial shade and others in full sun
- Choose a spot in the garden where the soil dries quickly (where the soil is well-drained)
You can plant your lily bulbs in a raised bed or similar, where the bulbs are on the surface of the soil and 15-20 cm of soil is placed on top of them. This makes the soil well-drained, which is important for all types of lily bulbs. If you plant them in a raised bed, remember to loosen the soil under the bulbs slightly before planting.
Depth
Lily bulbs should generally be planted 10-20 cm underground, depending on the species of lily and the type of soil it is planted in. However, there are some species (such as Madonna lilies) that only need to be covered by a few centimeters of soil.
Even though most lilies naturally grow in clusters, there should be about 20 cm between the bulbs when they are planted. In pots, however, the bulbs can be closer together (but not touching).
Fill the bottom of the planting hole with a small amount of gravel or pebbles to ensure drainage in the soil around the lily bulb.
Cold
Lily bulbs are relatively hardy, but when they start to sprout, they become slightly less resilient as their sprouts make them more susceptible to frost, insects etc. Placing the bulbs deep enough in the soil will protect them from the cold (in winter and spring).
To further protect the lily bulbs from the cold of winter, a winter cover can be used; spruce twigs are especially recommended. As a rule, lilies do not need to be dug up before winter. Trumpet lily bulbs and their sprouts are more vulnerable to cold than other lilies.
If spring is cold – which is often the case in Denmark – you can place the bulbs in pots in a cool but frost-free place.
Warmth
In summer, lily bulbs thrive best if they are not too hot; and if they are deep enough in the ground, it almost never gets too hot.
Soil conditions
All lilies thrive best in well-drained soil. Whether the soil should be acidic or alkaline (calcareous or calcareous) depends on the type of lily.
Also note that some lily bulbs (such as daffodil bulbs) should be planted deeper in sandy soil than in clay soil.
Fertilizer
It generally applies to all lilies that their fertilizer should not contain excessive levels of nitrogen (nitrogen). Using nitrogen-rich fertilizers will result in weak flower stalks.
Watering
The vast majority of lilies only need plenty of water during the watering period – after flowering and especially after deflowering, they usually need no more water.
You can use a summer cover to prevent the moisture in the soil from evaporating and to keep the lily bulbs cool. Of course, a summer cover also reduces the need for watering.
Dividing
Lily bulbs divide relatively quickly and after a few years you should usually dig them up. You should then divide the bulbs and replant them immediately.
If the flower stalks start to become too thick, you can also divide the bulbs. This should be done in late summer or early fall.
In general, most lilies should be divided every 5-10 years.
Storage of lily bulbs
Lily bulbs should be stored in a cool, dry place without light. Heat, moisture and light can cause the bulbs to sprout prematurely – and moisture can even cause them to wilt. The optimal solution is to store them suspended in a net or large mesh bag in a dry loft, garage or similar.
If you have bought lily bulbs before they are ready to be planted, you should ensure that they are stored with the aforementioned precautions in mind as soon as possible.