About Plant Select

A little while back, I told you about the faboo new plant I have for my garden. Actually, I bought more than one: I bought a flat. That would be 18 Red Feathers, echium aoneum, from Plant Select.

It was brought to my attention some echiums are problematic, i.e, invasive in some parts of the country. To be certain I wasn’t crossing into dangerous territory, I checked in with Pat Hayward, Executive Director of the Plant Select program to see how they evaluate particular cultivars, etc, before putting them out there for the public to swoon over. Here’s her response:

There are several ways that plants come through the program:

1. The first group of plants are those that have been growing at Denver Botanic Gardens for years (sometimes up to 30 years) and have proven to be hardy and meet our protocols for selection. If DBG is the only place it’s been grown, we get the plants out to trials at 7 sites around the region for evaluation. Evaluation officially takes place for 1-3 years. If there has never been a “seeding-around” problem, plants at this level are being tested for performance only. If it has a “seeding around” problem at DBG, it shouldn’t come into the program, but sometimes they do. For example, we’re currently testing about 6 species of alliums from DBG, but so far it looks like at least 4 of them are “seeders” so will get kicked off the lists and torn out of the test areas.

2. If it’s brand new to the horticulture, the plants will be tested 2-5 years at these 7 sites as well as at propagators’ locations and private gardens.

3. If it’s something that’s been around for awhile but not readily available, it may not go into trialing at all, or may go to the regional sites for a year or two. These are plants that we call “recommendations.” These often don’t need testing because they’ve been around so long, just what we call “underutilized.”

Other notes

· We require annual evaluations from all testers.

· Out of the 9 species of echium listed on the USDA Plants Database, only two are listed as noxious or weedy. E. amoenum isn’t even on the list, but it has been grown by quite a few of our cooperators for quite a few years. And though it will occasionally seed in the garden, the seedlings are always found local to the parent plant because the seed are very heavy and not able to get airborne. They also don’t form the little burrs like E. vulgare does, so it’s not easily carried off by critters in their fur.

Here’s our list of protocols for selecting and evaluating plants:

New plants listed for consideration for future promotions must be evaluated on:

1. Performance in a broad range of garden situations in the Rocky Mountain region
2. Adaptation to the region’s challenging climate
3. Uniqueness
4. Disease and insect resistance
5. Exceptional performance under low water conditions
6. A long season of beauty in the garden
7. Noninvasiveness
8. Capability to be mass produced
9. Retail appeal and longevity in containers
10. Quantity currently available and number of current propagators
11. Knowledge of basic propagation protocols
12. Images available for publication

All that said, there have been plants in the past that have come through the program that shouldn’t have and those are quietly being left to wither as we no longer promote them or even mention them in our talks. The prime example was Spartina, and none of our growers are growing it anymore.

Thanks for asking – yes, it’s a big question, and we’re trying to be diligent before introducing unknowns to horticulture.

Plant Select® is a collaboration of Colorado State University, Denver Botanic Gardens and the green industry to seek out and distribute the best plants for landscapes from the High Plains to the Intermountain region and beyond. Plant Select® is also a 501c3 nonprofit organization.