In the Collins Nursery of the Ambler Arboretum, not every plant is grown solely to find its place in a home garden. 

According to Collins Nursery Manager Sam Makler, the nursery is also involved in several efforts to support plant conservation, most recently with the Scarlet Paintbrush (Castelleja coccinea), the populations of which have grown extremely small in the wild in Pennsylvania. 

“Scarlet Paintbrush is a plant that has diminished so greatly that we’re left with only two populations in Pennsylvania. Historically this was far more expansive throughout the state, and there were many populations,” Makler said. “This has been impacted due to habitat loss. The environment that it grows in is so specialized and we’ve lost that over many decades.”

At the nursery, Makler said, “folks are familiar with the retail side of things — we do grow our plants primarily for folks to come and shop — but alongside that effort, and something that is near and dear to my heart, is the rare plant propagation and conservation that we’re able to do.”

“What we’ve been really excited to work on is this sort of seed bulking effort. We received plants from Penn State — they have been working on germinating plants for our local populations,” he said. “We received a large collection of those plants early on in the spring. Through this season, we’ve been able to pair them with a viable host plant.”

According to Makler, the nursery uses Packera paupercula as the host plant, “which is a species of Packera that grows right alongside (Scarlet Paintbrush) and its population.”

“Once we’ve paired them, they grow out and we’re able to allow them to flower. They’re successfully pollinated here at the nursery and then we are able to collect the seed,” he said. “So, the seed bulking effort is in turn going to allow us to grow out exponentially. If we started with 100 plants, we’re getting thousands and thousands of seeds, which in turn can in future seasons become thousands and thousands of plants.”

Fringed Gentian (Gentianopsis crinita), according to Makler, is also grown in the nursery for seed collection “so we can do reintroduction projects out in nature.”

“We work with private and public landowners to collect seed from where there are populations of the plant and then we will grow it out from limited seed quantity and then be able to reintroduce and reestablish populations,” he said. “As we move forward in the nursery here when we do these projects, we’re hoping that each time we have these kinds of rare plant conservation projects we can take a subset and offer those up to folks at home.”

A portion of the Scarlet Paintbrush plants that have been grown in the nursery this season, Makler said, are being planted out in the wild in the state during the fall months. 

“The Scarlet Paintbrush really embodies this idea of the kind of impact the nursery can have in something like rare plant restoration and conservation, the whole gambit of working with rare plants specifically — what is our impact in such a short amount of time,” he said. “We’ve only grown this since the early spring of 2026 — we’ve been working with it for a full growing season. In that time, we’ve been able to grow out and get flowering material on the many small plants that we started with; they’re growing out and putting off 5, 10 flowers in the best cases.”

In terms of the actual restoration efforts and the work “specific to the plant and the field conditions, in that short amount of time, we’re able to undo decades and decades of decline,” Makler said.

“Its natural conditions and its field populations have declined so tremendously. But in just one growing season we’ve been able to do many out plantings,” he said. “We’ve taken those two existing populations and have potentially brought it up to seven, eight new populations where this is growing now.”

According to Makler, support for the nursery through its Open Days and other efforts help fuel its conservation initiatives. 

“It’s an unbelievable impact that we can have through these propagation efforts. Folks coming here and supporting the nursery is the sole reason we’re able to do this work,” he said. “The field conditions, the natural populations and the status of them is directly tied to the folks that are able to support us right at the nursery and we can’t thank them enough.”