Eustoma from seed: winter sowing, rosetting and cutting for a vase

In short: Eustoma (Eustoma grandiflorum, also lisianthus) is a cut-flower annual here that must be sown as early as December to February. The tiny seeds germinate in light at 20–22 °C in 10–15 days, and about 5 months pass from sowing to flower. It is planted out after the frosts and flowers from July to September.

Eustoma looks like a cross between a rose and a tulip: silky flowers in white, cream, pink, purple or two-tone, single or double, on firm stems. It is popular in arrangements because it lasts a long time in a vase and the buds open one after another.

It does deserve its reputation as a difficult plant, though. The seeds are as small as dust, for the first two months the seedlings hardly grow, and a single temperature mistake is enough for only a ground-level rosette to form instead of a stem. Below is a method that works on a windowsill and in a small greenhouse.

What eustoma is and why start so early

Eustoma belongs to the gentian family and comes from the prairies of the southern USA and Mexico. At home it is a short-lived perennial; in our climate it is grown as an annual because it does not overwinter outdoors. The older name Lisianthus is still used by florists today.

Timing is the key. Roughly 5 months pass from sowing to the first flower, and you can plant it out only after the frosts. Anyone who sows in April will see the first flowers only in September, just before the cold nights. That is why eustoma is sown among the first plants of the year, together with pelargoniums and begonias.

Sowing step by step

The seeds are often coated (pelleted) so that they can be handled. The coating has to soften, so keep the compost constantly moist after sowing.

1. Timing: December to February. Allow 12–14 weeks from sowing to planting out. For a late sowing in March choose low, early varieties.
2. Compost: fine seed compost without coarse parts, moistened beforehand. Use a tray or a cell tray, with 1–2 seeds in each cell.
3. Do not cover: the seeds need light to germinate. Just press them lightly onto the surface. If you want to limit algae, you can dust them with a thin layer of vermiculite, but not with soil.
4. Temperature and moisture: 20–22 °C, cover the tray with a lid or film. Water only with a sprayer or from below; a stream of water would wash the seeds away.
5. Light: after emergence in 10–15 days give the seedlings as much light as possible, ideally 12–14 hours a day. On a winter windowsill that means supplementary lighting, otherwise the seedlings stretch.
6. Ventilation: uncover the lid gradually; in an overwatered and unventilated environment the seedlings damp off.

For general advice on germinating tiny seeds, see the article seed germination – techniques for every type of plant, and for an overview of other winter sowings the article what to sow in January.

Why eustoma does not form a stem: rosetting

The most common disappointment for growers is that the plant stays a low rosette of leaves and does not send up a stem, or does so only very late. This is called rosetting and is triggered mainly by high temperature in the first weeks after emergence, typically on a windowsill above a radiator or in an overheated greenhouse.

• Grow seedlings after emergence at 15–20 °C, cooler at night if anything.
• Do not leave them for long in heat above 25 °C in the first weeks.
• Give them enough light so they grow evenly and do not stretch.

Pricking out and hardening off

When the seedlings have 2–4 true leaves (usually after 6–8 weeks), transplant them individually into cells or pots 5–9 cm in diameter. Be careful, as the roots are delicate and tear easily. Continue growing at 15–18 °C in light.

From the beginning of May harden them off: outside in partial shade during the day, indoors at night. Plant out after mid-May, once night temperatures no longer fall below 10 °C.

Growing in a bed and in a container

Eustoma wants well-drained soil with plenty of humus and a neutral reaction; in heavy wet soil the crown rots. Pinching out the tip of a young plant promotes branching and more stems, but it delays flowering by a few weeks. For cutting a denser spacing and one strong stem per plant is better.

What to watch out for

• Damping off of seedlings (fungal rot at the base): the cause is overwatering and too little air. Clean seed compost, watering from below and ventilation help.
• Grey mould (Botrytis cinerea) on flowers and leaves in damp weather. Do not water on the leaves and remove faded flowers.
• Crown rot on heavy, waterlogged soil. Plant in well-drained soil, or in a raised bed.
• Thrips and aphids on the buds; damaged flowers are spotted.
• Late sowing: there is no point sowing in April, as the plants will not have time to flower.

Cutting and arranging

Cut the stems in the morning or evening, when at least one flower is open on the stem and the other buds are showing colour. Unopened green buds will not open in a vase. Remove leaves that would be under water and cut the stem at an angle.

Eustoma is one of the longest-lasting cut flowers, often lasting around two weeks in a vase. A clean vase and changing the water every two days help; more tricks are summarised in the article how to keep plants beautiful in a vase for a long time.

Frequently asked questions

When should I sow eustoma?

From December to February, at the latest at the beginning of March. About 5 months pass from sowing to flower; a later sowing will flower only at the end of summer or not at all.

Do you cover eustoma seeds?

No. The seeds need light to germinate, so just press them onto the surface of moist compost. At 20–22 °C they emerge in 10–15 days.

Is eustoma an annual or a perennial?

In the wild it is a short-lived perennial, but here it does not overwinter outdoors and is therefore grown as an annual. Overwintering in a cold greenhouse is possible, but plants in the second year are usually weaker.

Why is my eustoma not growing?

For the first two months it grows very slowly; that is normal. If it stays a low rosette without a stem, the cause is usually heat in the first weeks after emergence. Slow growth is also caused by lack of light and cold below 15 °C.

How long does eustoma last in a vase?

Usually around two weeks, if you cut it with at least one open flower and change the water regularly. Buds that are already showing colour gradually open in the vase.

Can eustoma grow in a pot?

Yes, choose low varieties up to 25 cm. They need a sunny spot sheltered from wind and a well-drained compost that neither dries out nor stands in water.

Recommended products

• Seed compost 5 l (suppressive) – a fine seed compost that limits fungal diseases of seedlings.
• Seed tray 19 × 14 cm – for sowing dust-fine seeds over the whole surface.
• MULTI cell tray 4 × 4 cm (48 pcs) – cells for sowing 1–2 seeds each and for pricking out without tearing the roots.
• Garland heated propagator OneTop L – keeps the 20–22 °C needed for germination even on a winter windowsill.
• Bamboo cane 90 cm, 25 pcs – a support for tall cutting varieties.

Sources

• NC State Extension: Eustoma grandiflorum
• Johnny’s Selected Seeds: Lisianthus key growing information
• BBC Gardeners’ World: Eustoma grandiflorum

Updated: 27 September 2026