Grow Lisianthus from Seed

Latin:  Eustoma grandiflorum

Growing lisianthus from seed can be a very rewarding but challenging process due to the plant's specific germination and growing requirements. By following these detailed growing instructions and the fresh seeds that we sell, you will enjoy their beautiful flowers. Be patient as these plants are slow growing in the early stages and take about 6 months to mature.

Where to grow lisianthus

Lisianthus are a great cut flower and ideal for a herbaceous border. They are tender perennials usually grown outdoors as annuals in the UK. They like a bright, well drained spot, which has been enriched with well-rotted compost. Flowering is initiated by short nights which they only get with long bright days.

How to sow lisianthus seed

The seeds we sell are high quality pelleted seed. The optimum time to sow the seeds is from January to March. Sow the seeds indoors in quality seed compost. Space the seeds out on the surface of the compost and then gently press them in. Ideally cover them with a thin layer of vermiculite. Do not cover the seeds as they need light to germinate. If you are keen and have a propagator and grow lights then they can be sown as early as November.

What are the germination conditions for lisianthus seed?

Place the seeds in a heated propagator at 21–24oC or in a warm spot in the house. With pelleted seeds it is important they do not dry out, so it is best to cover the seeds with a mini greenhouse or clear plastic bag.  After planting, spray the compost to make sure it is wet but not waterlogged.

How long do lisianthus seeds take to germinate?

Germination is expected to take between 8 to 14 days depending on the temperature. When they have germinated remove the cover to allow the air to flow and avoid damping off. Reduce the temperature to about 18OC (64OF) and grow them on until large enough to be potted on.

When do I pot up the lisianthus seedlings?

Allow the seedlings to develop their 1-2 sets of true leaves and transplant them into individual pots. It is important to avoid overcrowding of the young plants which will  slow the growth down. Continue to provide good light and grow them on at about 18OC (64OF) until they are ready to plant out. If temperatures are too high at this stage they may not flower well.  They will benefit from a regular half strength, diluted liquid fertilizer to keep them growing steadily. At this stage they are quite slow growing.

Hardening off my lisianthus plants

Lisianthus are frost tender plants so it is important to harden off your plants before planting them out in their final position. Move the plants from the greenhouse or windowsill initially to a sheltered spot outside. Keep an eye on the weather and if it gets cold then make sure you protect them at night. Allow a couple of weeks to fully harden off your plants.  

When do I plant out my lisianthus plants

When all risk of frost has passed, plant out in a sunny well drained spot which has benefited from some extra compost or manure. Space the plants out 15–30 cm apart (check the requirements of individual varieties). They can also be grown in a polytunnel or greenhouse. This will help protect the blooms from water damage.

How do I care for my lisianthus plants?

Keep the area clear of weeds and water the plants well in the morning rather than the evening. Keep a check for slugs which will soon destroy all your hard work. The plants will reward you with beautiful flowers from late spring through the summer. Many of the varieties available make great cut flowers.  

Best Selling Variety

Lisianthus Sapphire mix is a delightful dwarf version that will make a great addition to your borders and pots.