Growing Lisianthus in the Pacific Northwest: From Plug to Summer Bloom
Growing lisianthus in the Pacific Northwest can feel a bit mysterious, especially for local gardeners and newer flower farmers in the Seattle–Tacoma area. These ruffly, long-lasting summer flowers aren’t commonly found in local nurseries, and much of the growing advice available isn’t written with Western Washington’s cool springs and mild summers in mind.
This post focuses specifically on growing lisianthus from plugs to flowers in the Pacific Northwest. Whether you’re planting lisianthus in a backyard cutting garden or adding them to a small flower farm, these tips are based on what has worked for me growing lisianthus in Edgewood, Washington.
I started growing lisianthus more than 25 years ago on the patio of my first apartment. Today, I grow lisianthus plugs for local gardeners and flower farmers at my small nursery and flower farm in Edgewood, Washington, plants that have proven to be worth the patience when grown with our local climate in mind.
Plant Lisianthus Plugs Soon After Arrival
In the Pacific Northwest, lisianthus plugs are best planted in early spring. Lisianthus benefit from a long, cool establishment period, allowing roots to develop before warmer temperatures and longer days arrive.
Plant lisianthus soon after you receive them. If watering is needed prior to planting, set the plugs in a tray or cookie sheet, pour water into the tray, and allow them to soak it up from the bottom.
Cold tolerance note: Don’t worry too much about cool temperatures after planting. In my experience, lisianthus can withstand hours in the upper twenties with no issues. If plugs are newly planted, I may mulch lightly or use frost cloth, though I don’t really find it necessary. One spring, a greenhouse circuit breaker tripped during 20-degree weather and my lisianthus plugs froze solid, yet they recovered just fine.
Prepare a Well-Amended, Well-Draining Bed
Lisianthus grow best in rich, well-draining soil. Amend your bed with quality compost and fertilizer before planting.
If you follow no-till growing practices, apply a 1–2 inch top dressing of compost with organic fertilizer mixed in.
Handle Roots Gently
Do not tease out the roots when planting. Lisianthus are tough little plants, but they prefer minimal root disturbance.
Plant Slightly Above Soil Level
To reduce the risk of crown rot, especially during our wet Pacific Northwest springs, plant lisianthus slightly above ground level in well-draining soil.
Space Plants for Airflow
Space plants approximately 4 inches apart to allow for good air circulation and healthy growth.
Optional Root Protection
Some growers dip lisianthus plugs in Rootshield at planting to help reduce fusarium root rot. While this practice is suggested by some plug suppliers and farmers, many growers who start lisianthus from seed report seeing no significant difference in field success rates.
Fertilize Regularly
Lisianthus require regular feedings. I apply a quality organic fertilizer high in nitrogen early on, switching to one higher in phosphorus as stems begin to elongate.
I also fertilize weekly with a calcium nitrate fertilizer. Here is a homemade option I use:
Korean Natural Farming Water Soluble Calcium Fertilizer:
Finely crush 12 or more eggshells and cook them in a pan until browned. (Use ventilation—it will smell.)
Place the cooked shells in a quart jar and fill with apple cider vinegar, leaving a little headspace.
Cover with cheesecloth. The mixture will bubble vigorously.
Let sit for 1–2 weeks, then strain out the shells and seal with a lid.
This mixture is shelf stable for months. I use 1.5 teaspoons per gallon of water.
Be Patient
Lisianthus are very slow growing. It may look like little is happening above ground, but the plants are quietly building a strong root system. Patience is an important part of growing these flowers.
Harvesting Lisianthus
The first bloom typically opens one to two weeks before the rest. Many growers harvest this initial flower for short-stem bouquets before cutting the full stem.
For longer stems, harvest when two to three additional blooms have opened. Condition lisianthus as you would other cut flowers.
Lisianthus reward patience with long-lasting blooms and soft, elegant beauty in the summer garden. For local gardeners and flower farmers in the Seattle–Tacoma area, growing lisianthus from plugs makes it possible to enjoy these blooms without starting from seed. Growing them locally means learning their rhythm, and enjoying flowers that last beautifully in the vase.
