How to Grow Lisianthus: 10 Tips for Growing Lisianthus

On a whim, I picked up a six-pack of lisianthus (Eustoma grandiflorum) at a local nursery several years ago. It was worth a try to see if they would survive the incredibly hot summers here in the low desert of Arizona. I wasn’t sure how to grow lisianthus, and I was shocked when they grew well all summer, and some returned the following spring! The beautiful rose-like blooms were a pleasant surprise.

Lisianthus is now a summer staple in my low desert Arizona garden. Learn how to grow lisianthus with these ten tips.

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10 Tips for How to Grow Lisianthus

1. Plant lisianthus from plugs or transplants

Lisianthus is tricky for seasoned nursery professionals to grow well from seed. Leave the sowing to the experts and purchase transplants or plugs. Local growers, nurseries, and online retailers may all sell lisianthus starts. Look for plugs or transplants with buds beginning to grow to ensure flowers are on their way.
Space lisianthus transplants about 4 inches apart. Most lisianthus plants grow tall, and spacing plants closely help them support one another as they grow. Transplant plugs and transplants a little higher than soil level to avoid stem rot.
Keep lisianthus transplants well-watered for at least two weeks. Do not allow it to dry out.
For square foot gardening, plant up to 8 lisianthus per square. Wider spacing yields larger plants.

2. Grow different varieties of lisianthus

Lisianthus varieties vary in height and color.
If you are growing lisianthus in containers, choose shorter varieties.
Longer-stemmed types of lisianthus will require staking or netting to stay upright.
Typical colors for lisianthus are cool tones of purple and pink.
Blooms are typically single or double types.
Choose a variety you enjoy and that suits your needs.

3. Plant lisianthus at the right time

Plant lisianthus transplants 2-4 weeks before your last spring frost. Transplants need 2-3 weeks of cool soil at the time of transplant to prevent “rosetting.”

January through March is the best time to plant lisianthus in Arizona’s low desert. Lisianthus can be planted through April or May, but results may vary.

Planting it early in the season gives lisianthus plenty of time to establish before summer heat in hot climate areas. If you plant later in the season, provide shade for new transplants until they are established.

Perpetual Flower Planting Calendar for Zone 9B

Flowers to Plant Outside & Seeds to Start Indoors Each Month in the Low Desert of Arizona.
• PLANTING GUIDE: Each month lists annual flowers and bulbs to plant outside & seeds to start indoors.
• BLOOMING GUIDE: Photos show what may be in bloom that month.

4. Give lisianthus the type of soil it needs to grow well

Lisianthus prefers neutral or even slightly acidic soil. Soil that is too alkaline will cause yellow leaves and overall poor health. Aim for a pH between 6.5 and 7.0.

Plant lisianthus in well-draining, rich soil with plenty of compost and organic matter. Raised beds are a good choice for growing lisianthus.

5. Choose a location with plenty of sunlight

Lisianthus is native to prairies and fields in the southern United States and Mexico and prefers warm, dry air. Cool humid locations may have difficulty growing lisianthus.

Choose an area in your garden to plant lisianthus that gets full sun. Lisianthus benefits from some afternoon shade if you live in a hot summer climate like the low desert of Arizona.

6. Water and feed lisianthus correctly

Lisianthus prefers moist but not soggy soil.
Avoid getting water on the leaves. Using a drip system is an effective way to water lisianthus.
If fungus gnats are an issue, let the top inch of soil dry out a bit between waterings.
Mulching soil will help retain moisture and keep weeds down.
Lisianthus benefits from rich soil and regular feeding from a flower fertilizer that is higher in phosphorus than nitrogen (the middle number in the N-P-K formula is higher than the first number).

7. Provide support for tall lisianthus stems

Lisianthus plants grow quite tall, and staking them individually can be tedious. Enter trellis netting – a flower farmer’s idea for vertical gardening you can add to your garden.

Use pole supports in each corner and stretch the net between the poles. I used this trellis netting from Amazon.
The netting is held taught between the four stakes.
Cut off the excess netting.
The flowers grow up and are supported by the netting.
For taller flowers, use two layers of netting several inches apart.

Lisianthus growing up through trellis netting

8. Encourage more blooms

Pinching back lisianthus transplants results in smaller stems but fewer blooms. Unpinched stems will be longer.

Remove the first bud/flower. This saves resources for the later flowers.

After the first flush of blooms, cut the stems back. Water and fertilize well to encourage an additional flush of blooms. This results in a more uniform set of second blooms.

For a less drastic approach and continual blooms, deadhead spent blooms by cutting each bloom back to where it emerges from two sets of leaves. Plants should continue to send up flower stalks while temperatures are warm.

9. Maximize vase life for lisianthus blooms

Harvest blooms in the morning when temperatures are coolest.
Remove the first flower and harvest the stem once the second set of flowers is open. The remaining blooms will open in the vase.
Use sharp scissors or pruners to cut the stem just above the base of the plant.
Strip all leaves below the water level in the vase.
Recut stems before adding them to the vase.
Replace water in the vase every few days as needed.

10. Grow lisianthus as a perennial if you live in a warm climate

This heat-loving flower grows well as an annual in most zones. However, lisianthus is a short-lived perennial and can be overwintered in warmer zones (zones 8-10).

To grow lisianthus as a perennial, cut back plants after the last blooms fade in the fall and mulch well with straw. Cooler zones may use row cover to prevent lisianthus from dying. New growth will emerge in the spring.