There are few flowers as beloved as the lily. Star-shaped, bright, and colorful, lilies are sure to stun whether in the garden or in a vase. However, if you’ve grown lilies in your garden, you know that you’ll only have blooms during the summer.
If you’re looking to ‘force’ lilies to bloom earlier, you can try your hand at growing lilies in the greenhouse. Because you can control the conditions inside, you can speed up the flowering and have blooms much earlier than you would otherwise! You can then bring your flowers indoors to enjoy, or simply leave them in the greenhouse to brighten up the space.
There are so many benefits to growing lilies in a greenhouse. Not only can you enjoy blooms earlier, but growing lilies in a greenhouse can also promote better growth and a healthier bloom. Keep reading to learn everything you need to know about how to grow lilies in a greenhouse!
Benefits of growing lilies in a greenhouse
Typically, lily bulbs are planted outdoors in late autumn or early spring, but they’ll only start growing when the temperatures warm up. If you don’t want to wait for summer to enjoy their beautiful flowers, you can force lilies to sprout earlier in a greenhouse.
The biggest benefit of growing lilies in a greenhouse is that you can speed up the growing process and have blooms earlier than you would otherwise. When you plant lily bulbs in a warm greenhouse after a chilling period, you can expect them to flower within just 6 weeks of planting.
Meanwhile, growing lilies outdoors starts later and takes longer. Although you usually plant lily bulbs in late fall, they won’t start growing until early spring and won’t bloom until about 1-3 months after that.
If you’re thinking about growing lilies in a greenhouse, consider these benefits:
- Promotes faster growth rates
- Encourages early or ‘forced’ flowering
- Prevents waterlogging of the soil, or soil drying out
- Promotes strong, healthy stems
- Protects early shoots from wind, rain, and snow damage
- Protects bulbs from some garden pests and disease
How to plant lilies in a greenhouse
Outdoors, lilies won’t bloom until spring when the weather warms up. However, in a greenhouse, they can be forced to bloom much earlier if the right temperatures are maintained.
You can grow lilies in a greenhouse any time of year, but the best conditions will always be during autumn or spring. Lilies can be grown clustered together, but ideally, you should only plant one bulb per container. This gives the bulbs room to grow and spread.
Here’s a quick step-by-step guide on how to plant lilies in a greenhouse:
- Choose a container (with proper drainage) that’s around 4 times the depth of your bulb.
- Fill the base of the container with pebbles to improve drainage.
- Add your soil mix to the bottom third of the pot.
- Add your bulb to the pot at a depth of around 2-3 times the size of the bulb itself – planting them deep like this will protect the shoots from frost damage.
- Fill the remainder of the pot with soil, leaving the top 2 inches (5 cm) of the pot free.
- Water thoroughly to let the soil compact around the bulb.
- Place in a bright, sunny position in the greenhouse.
It can take anywhere from a few weeks to a few months for the bulbs to sprout and push up through the soil. The important thing is, keep the soil moist but not water-logged, and be patient.
How to care for lilies in a greenhouse
Once the shoots emerge, you can expect full blooms in 1-3 months, as long as the lilies receive all the necessary care. For the best blooms, it’s important that the conditions in your greenhouse are adequate. Even more so if you’re trying to force blooms out of season!
If you can maintain the following conditions, you should have beautiful lilies in no time.
Ideal soil conditions
Most lilies aren’t too fussy when it comes to soil. However, certain lily species have more particular requirements, so do some research when buying your bulbs. Generally, most garden soil with a pH of about 6-7 will do.
Most importantly, the soil should be well-draining to prevent rotting or disease. So when growing lilies in a greenhouse, it’s best to use loamy soil. If creating your own, mix compost with vermiculite or perlite.
To improve drainage and moisture retention of the soil in containers, you can mulch the top 1-2 inches with sawdust, wood chips, and/or compost.
Temperature and lighting
Lily bulbs only sprout when the soil is above 50°F, and do best when the temperature is increased slowly after planting. Remember, lilies need to undergo a cooling period (winter) which can be done artificially to force early blooming.
Once growing, lilies need a lot of sunlight to thrive. Make sure you place them in a sunny position in your greenhouse that gets at least 6 hours of full sunlight every day. If the stems start leaning to one side as they grow, they aren’t getting enough sunlight. Move them to a sunnier position in the greenhouse or supplement with grow lights.
The optimal greenhouse growing temperature for lilies is between 65-75°F. If you plan on transferring your lilies outdoors, you’ll need to wean them off the controlled environment gradually, just as you’d harden off young sprouts before planting them outdoors. You should only do this when the temperatures are above 65°F and no rain is forecasted.
If you’re keeping your lilies in the greenhouse throughout the summer, the other challenge becomes ensuring temperatures don’t get too hot. Lilies won’t survive extreme heat, so keep your greenhouse well ventilated and no hotter than 75°F. You can mulch the soil around your lilies to keep the soil temperature cooler.
Watering
Lilies are thirsty plants! They like their soil moist, but not wet. You should water your greenhouse lilies regularly, but just how much depends on how quickly your soil dries out.
Never let their soil dry out entirely, as this can impact the bloom in later months. Likewise, making sure the soil isn’t water-logged will prevent root rot.
The bottom line? Consistency. By maintaining a regular watering schedule from early on, you can ensure large, exquisite blooms.
Fertilization
For the best growth and most beautiful blooms, you’ll need to make sure that your lilies have adequate nutrients. Fertilization is especially important when forcing early blooms.
You can use a nitrate or ammonium sulphate mixed with water, or feed with a high potassium liquid fertilizer (like a tomato feed), approximately every 2 weeks during the growing season. This will encourage strong growth and ensure the soil in your containers isn’t devoid of nutrients.
Pests and disease
Growing lilies in a greenhouse protects them from many of the pests and diseases that are in the garden. However, pests and diseases that do make it inside can actually cause more damage to your lilies which have thus far led fairly easy lives.
The red lily beetle is one of the main pests that lilies are subject to. These small beetles feast on the leaves and can be detrimental to the growth of the plant.
The damage is often unnoticeable at first, but when a plant becomes infested you will start to see wilting foliage and even undersized buds. To prevent this damage, make sure to inspect your plants for red beetles and pick them off by hand before they can do more damage.
Like many other plants grown in greenhouses, lilies are also susceptible to slugs, snails, and fungal gnats. Maintaining clean greenhouse conditions can prevent most pests and diseases, so make sure to routinely clean water puddles, wipe down surfaces to prevent algae buildup, and don’t overwater your plants.
What lily species do well in containers?
It’s no secret that some plants don’t appreciate being planted in containers. Luckily, lilies aren’t one of them! In fact, all varieties of lilies are known to perform well in containers and can be grown in a greenhouse environment.
To grow lilies year after year, however, you do have to dig up the bulbs and either plant them in the garden during the winter or recreate a chilling period by freezing them for at least two months.
Some species of lily take longer to bloom, so you can grow a combination of different ones to have blooms throughout your growing period!
In a greenhouse, you can grow:
- Asiatic lilies: these are the first to bloom, typically just 30-45 days after planting
- Easter lilies: typically grown and forced to bloom around Easter
- Oriental lilies: fragrant and slower-growing, blooming between 40-90 days after planting
- Trumpet lilies: known for their trumpet-shaped flowers, similar growing period as Oriental lilies
- Tiger lilies: take the longest to bloom, around 100-120 days after planting
Planting different varieties in the greenhouse will mean you can have lily flowers throughout the spring, summer, and even early autumn! Browse your favorite online bulb supply company for the most diverse selection of bulbs.
