Mystery tree is likely a black locust tree

Q: A couple of doors down from our home there is a large, round-headed shaped tree in the yard that has fairly large clusters of white blooms. Sort of shaped like a cluster of grapes. When we asked what type of tree it is, we were told it’s a locust. It’s just that we think locust trees have purple blooms. Could this tree be a locust, even though it’s blooming white flowers? — M.C., Albuquerque

A: It sounds to me like you’ve stumbled upon a black locust tree (Robinia pseudoacacia). This tree is a relative of the tree that you are most familiar with — a purple robe locust — which is in a hybrid locust category. Nonetheless, I think this one, from your description, sounds like a black locust.

“Western Garden Book” says that emigrants brought the seeds with them from the eastern U.S. and now it is common everywhere. Most locusts can and are thought of as drought tolerant, and in some areas they’ve gone native. That term drought tolerant does make me crazy, though. Any tree, shrub, bush, rose, perennial or annual plant will require maintenance watering, period. Forgive me, I just had to get that said.

When I first read your question, I wondered if you were looking at a catalpa tree, but I haven’t seen any catalpas fully leafed out yet, much less in bloom. I believe that yes, you are seeing a locust, just the variety black locust wearing the white bloom clusters. Enjoy!

Q: Planted in one of the medians on a larger road near my home here on the West Side, there are two different plants in bloom right now. The first one is a smallish bright green mounding plant that is showing spikes of really pretty bright red smallish flowers. The other plant is more creeping, has white pinkish flowers and wears sort of pale green leaves. Any ideas as to what either of these two lovely plants are? — N.M., Albuquerque

A: I think I know which plants you are describing that are showing off now.

The first one, the green mounding plant, I believe is Texas red salvia (Salvia greggii). This salvia is considered a semi-evergreen, meaning it’ll keep some of its green color of the mound all winter long and then reawaken in the spring with a fresh coat of greenery and then flush the bloom spikes. The spikes, upwards to 8-inches tall, wear smallish near sweet pea shaped blooms that last for a couple of weeks. The ones I think you’re noticing are a nifty dark red color. This salvia variety is fairly easy to grow and it is well-mannered, meaning it doesn’t spread and isn’t considered invasive in the least. You should be able to find Salvia greggii available in any well stocked nursery here in the Metro area.

The other plant you’re seeing, I believe, is Mexican evening primrose (Oenothera). You’re correct in defining the foliage as a sort of pale green, with the flowers being a four-petaled white pale pink color. I’ve seen some that wear blooms of only pink, but nonetheless, I am confident that this creeping plant you’re noticing is Mexican evening primrose.

Now, I do have a couple of cautions about this one. Know that it can be considered invasive. Meaning, once it gets a foot hold, you could have it around for years. It tends to spread by underground rhizomes and can act a lot like the dread bindweed. If you break it off at ground level, it’ll more than likely come back stronger than ever. I know some people that keep their patches of Mexican evening primrose mowed, and it is a bit more mannerly by doing that. I wouldn’t recommend planting this one in a perennial flower bed and plan on it behaving. It usually won’t.

Think of this plant as more of a ground cover that doesn’t want or need a lot of tending. Just remember it will spread and sometimes show up in places you don’t want it to. I’m pleased that you keep your eyes open and notice the plant life that surrounds us, and are curious enough to ask when you see something that strikes your fancy.

Keep on Diggin’ In and remember, it’s time to ramp up your maintenance watering for all your landscaping!

Tracey Fitzgibbon is a certified nurseryman. Send garden-related questions to Digging In, Albuquerque Journal, 7777 Jefferson St. NE, Albuquerque, N.M. 87109, or to features@abqjournal.com.