I was very excited to plant some gooseneck loosestrife in my garden but it has proven to be a dismal failure. It’s been three years and the plant is refusing to “gooseneck”. Instead, it gives me very frail flowers, reaching straight up and lasting a very short time. I’m at the point of pulling it all out, but wanted to see if there was any way to encourage it to offer up some healthy, bobbing white flowers.
What are the conditions where the gooseneck loosestrife (Lysimachia clethroides) is planted? This plant tolerates
partial shade to full sun. The fact that yours is growing straight up makes me wonder if it is in too much shade and is striving for more light. Usually, this is a vigorous plant (sometimes exceedingly so–it can become invasive), so other things to consider are soil conditions (prefers well-drained soil with a lot of organic matter), and moisture. If planted in full sun, loosestrife will need sufficient water to thrive.
It is possible, too, that after 3 years, your plant needs to be dug up and divided. This might help give it renewed vigor. Propagation information from the Iowa State University Extension suggests that “Perennials such as gooseneck loosestrife (Lysimachia clethroides)… may be divided every 3-5 years to improve plant health.”
Other good sources of information about this plant are Cornell, and the Kemper Center for Home Gardening.