What Are Rare Plants and How Do You Start Collecting Them?

Rare plants are plants that are scarce in cultivation, hard to source, or limited to specialized collections—not simply plants with unusual looks. You can start collecting by choosing a plant group that matches your garden conditions, buying from specialist nurseries or collection gardens, and beginning with easier woodland or shade plants before moving to demanding species. A collection garden such as Mill Fleurs in Bucks County, Pennsylvania, shows how this works in practice: it is a private garden and nursery built around shade plants, and it offers guided tours, lectures, and tours by appointment.

What "Rare" Actually Means

A plant can be rare for different reasons, and the reason affects how you grow it:

• Scarce in the trade: Few nurseries propagate it, so it is hard to buy.
• Slow or difficult to propagate: It may be common in the wild but rarely offered for sale.
• Restricted to collectors: It circulates mainly through plant societies and private exchanges.
• Narrow habitat: It comes from a specific woodland, alpine, or wetland environment and needs similar conditions at home.

"Rare" does not automatically mean "delicate." Many collector plants are tough once their basic requirements are met. The real challenge is usually finding them and matching their conditions.

The Main Categories Collectors Chase

Mill Fleurs describes itself as a collection of plant collectors "heavy on shade plants," and its plant list is a useful map of what rare-plant collecting often looks like:

The garden also notes that its site was once densely shaded before trees were lost to hurricanes, tornadoes, and deliberate thinning of ash forest to limit emerald ash borer damage. That detail matters for collectors: shade-garden collections depend on a tree canopy, and canopy loss changes what will grow.

How to Start Collecting

1. Match plants to your site first

Before chasing a specific plant, assess your light, soil, and moisture. A shade-plant collection needs reliable shade and woodland-style soil. If your garden is sunny and dry, start with collectors' plants suited to those conditions instead.

2. Pick one plant family

Collectors often focus on a single genus—hosta, epimedium, or galanthus—because it makes sourcing, comparing, and learning easier. Mill Fleurs' repeated emphasis on hosta shows how deep a single genus can go.

3. Source plants deliberately

• Specialist nurseries that propagate collector plants.
• Plant societies and collector exchanges, where rare material circulates.
• Collection gardens that sell or share plants; Mill Fleurs operates as a garden and nursery.
• Lectures and guided tours, which are often where sourcing leads and cultivation advice come up.

4. Start with forgiving species

Begin with woodland plants that tolerate average garden soil and some drought, then add the fussier species once you understand your site.

5. Verify hardiness and provenance

Ask about cold hardiness, soil pH, and whether a plant is nursery-propagated rather than wild-collected. Nursery propagation keeps rare plants available without pressure on wild populations.

What to Look For on a Collection Garden Visit

Mill Fleurs' own site states that the gardens are closed for the season, with the spring opening announced on its Events page—so check timing before planning a visit. When you do go, use the visit as research:

• Ask what grows well on the site and what fails. The garden's history of canopy loss is exactly the kind of local knowledge a tour can explain.
• Look at plant combinations, not just individual plants. How shade plants are grouped tells you about soil and moisture management.
• Ask where the plants came from. A collector's sourcing network is often more valuable than any single plant.
• Note what is in bloom and when. The site's "What's in Bloom" section signals that seasonal timing shapes what you will see.

For Bucks County garden tours specifically, confirm dates, whether tours are guided or by appointment, and whether the nursery is open when the garden is not.

Common Pitfalls

• Buying by rarity alone. A rare plant that does not fit your site is an expensive loss.
• Ignoring canopy and shade changes. Shade collections are only as stable as the trees above them.
• Skipping quarantine and hygiene. New plants can carry pests; isolate and inspect them before planting among a collection.
• Assuming a garden is open. Collection gardens often run limited seasons or appointment-only visits, as Mill Fleurs does.

Bottom Line

Start with your site, choose one plant family, and source from specialist nurseries and collection gardens rather than general retailers. Treat a visit to a collector's garden—like Mill Fleurs in Bucks County—as both inspiration and practical research, and confirm opening dates and tour arrangements before you go.