Lilies won’t bloom if the bulbs are too small or immature, too close together, planted too shallowly, or too shaded. If winter temperatures are too mild, some lilies will not bloom because they need a cold season to bloom.
Lilies need full sun, good, even soil moisture, and not too much fertilizer to bloom properly.
Read on to find out why your lilies aren’t blooming and make sure your lilies bloom well next year
1. Size and Quality of Bulbs Can Affect Lily Flowering
If your lilies are not flowering a year or so after planting then this may be because of the size and maturity of the bulb.
It takes a lot of energy for a single bulb to bloom, and small bulbs often don’t have the energy and resources a lily needs to grow and bloom in its first year.
Instead, they divert their energy from flowering to growing and establishing themselves in new soil conditions. As the bulb grows and matures, it is more likely to bloom the following year.
Larger, more mature bulbs are more likely to produce lilies because they store more energy for the plant to bloom in the spring.
When choosing bulbs for lilies or other flowering plants in the garden center, it is important to be discerning about the selection of your bulbs ensuring that you buy the biggest healthiest looking bulbs possible to ensure healthy lilies and good display of flowers after planting.
2. Over Crowded Bulbs Causes Fewer Flowers
A common cause of lilies not blooming is when the bulbs are planted too close together.
When the bulbs are overcrowded, they compete with each other for space, nutrients, moisture, and sunlight when green leaves emerge in the spring.
The solution to this problem is to dig out the bulbs and plant them separately so that each lily gets all the resources it needs to bloom.
To ensure the best view of flowering lilies, keep each bulb at least 20 cm apart. This will ensure that the lilies are close enough to bloom well and have plenty of room to thrive.
If your lilies are not blooming and you know they are too close together, dig them out (ideally in fall) and place them properly so they have enough time to acclimate to their surroundings before they grow and bloom in the spring.
3. Shallow Planting of Lily Bulbs Reduces Flowering
The depth at which your lily bulbs are planted can affect flowering. Bulbs that are planted too shallow can suffer from frost damage (which prevent lilies from flowering) whereas bulbs planted too deep can either flower later or not flower at all.
The best way to plant lily bulbs is to plant the bulbs to a depth of 4 times the diameter of each bulb. This provides shelter in winter and keeps bulb growth strong and healthy in spring.
4. Lilies Prefer Full Sun for Blooms
For most lily varieties, about 6 hours or more of sunlight per day is the preferred method of blooming.
In 6 hours of sunlight, lilies have the energy they need to bloom, while lilies grown in partial or full shade will usually grow but not bloom.
If your lilies are in the shade of your garden, you should trim any overhanging branches or leaves around the lilies to add light.
If you can’t create more light by cutting down other plants and trees, it’s best to wait until the lily leaves die before digging up the bulbs in the fall, and then move them to a sunny spot in the garden.
Do not try to transplant lilies during spring or summer growing periods, as this can cause transplant shock.
A sunny spot will give your lilies more energy, which should result in a nice bloom.
Keep in mind that there is a greater risk of drought in full sun, so mulching the soil is a good idea
5. Lilies Require a Cold Winter to Display Flowers
One of the most common varieties of lily is the Asian lily, which actually needs a cold period of winter to bloom in the spring (a process called vernalization).
This is because the bulbs have adapted to the seasonal cycle of temperature changes, so the bulbs know when to start growing and need to flower at the right time in the spring.
Asian lilies adapt to the temperate climate temperature model. Therefore, if you are growing Asian lilies in a warmer rather than temperate climate, winters may not be cold enough for the vernalization process, and the plants may not grow well and not bloom.
6. Too Much Nitrogen Causes Foliage with Fewer Flowers
Lilies tend to grow best in rich, nutrient-rich soil and usually do not require any supplemental fertilizer to bloom.
Too much fertilizer, especially one high in nitrogen, often promotes lots of green leaves, but few blooms, especially when applied in early spring before blooming.
Once you have applied fertilizer to a developing lily there is not much you can do to promote flowering, apart from scale back the use of any fertilizer and wait for the following year.
For lilies that are in poor soil or perhaps in potting soil where they may have exhausted the nutrients a fertilizer applied after blooming can be useful.
7. Removing Leaves From Lilies Too Early Reduces Next Years Flowers
In neat formal gardens, some gardeners may prune the lilies after they bloom, rather than waiting for the leaves to turn yellow and brown in the fall.
However, if the leaves are clipped after the lilies have bloomed, they won’t be able to store energy in the bulbs for the following spring, so they may not bloom.
Lily leaves are alive after flowering and use the remainder of summer and fall to absorb nutrients and harvest energy from the sun for growth and flowering in future years.
It is best practice to wait until the leaves have turned yellow or brown at the end of Fall before cutting away the foliage to promote the lilies flowering.