Thursday, March 10, 2011

Chitalpa vs. Desert Willow vs. Catalpa

Desert Willow or Desert Catalpa
While writing on the Desert Willow, I thought I'd share something that confuses a lot of Tucson gardeners.....the differences between the Chitalpa and the Desert Willow.  What do they both mean?  And how do you tell them apart?  Both trees grow here and both have similiar growing habits.  Generally, they are similiar plants with the exception that the Desert Willow is a native for Southern Arizona as it grows along canyon beds and rivers here.  The Chitalpa is a bit more tropical in appearance with thicker leaves. Catalpa is yet another tree that I occassionally see around Tucson, but I wouldn't recommend growing this one as it can receive severe damage from our cold nights. People have reported, through my various questions, that their trees suffered cracking in their trunks during extreme frosty nights. This is definitely a more tropical type tree.  I think I'd put this one in a pot if you want to try it out. So what are the differences? And why are they important?

If you look at the pic of the chitalpa, you'll notice thicker leaves and a slight color varietation. The chitalpa also has different colored flowers when compared with the traditional bright pink of the Desert Willow.  Why are these two trees similiar?
The Chitalpa, X Chitalpa tashkentensis, is a hybrid between the Desert Willow and Catalpa tree.  This combination is a hit for many people and were designed for our desert community.  Here is some info from Dr. David L. Morgan on the Chitalpa tree....

"The chitalpa is as unlikely a tree as one might imagine. After all, who would’ve thought the cross between the catalpa (not the most desirable shade tree) and the desert willow (one could hardly describe it as a stately specimen) would turn out so well? But it certainly did.

Perhaps A. Russanov of the Botanic Garden of the Uzbek Academy of Sciences in Uzbekistan didn’t feel the same way about the parent trees when he created the hybrid between Chilopsis linearis (desert willow) and Catalpa bignonioides (Southern catalpa) – both members of the Bignoniaceae, or trumpet vine family. That was back in 1964, when relations were icy between the US and the Soviet Union. The cross finally made its way to the US in 1997, when Robert Hebb of the New York Botanic Garden introduced it. The hybrid remained unnamed until the Rancho Santa Ana Botanical Gardens in Claremont, CA, gave it the common name “chitalpa.” The gardens also named two chitalpa cultivars: ‘Morning Cloud’ (with white flowers) and ‘Pink Dawn’ (with pale purplish-pink flowers and pale yellow throats).

Chitalpa carries some of the best traits of both parents, yet it’s sterile, so it doesn’t produce the abundant, messy seedpods of either. What’s more, its mature flowers don’t drop on sidewalks, causing a slippery goo, as does the desert willow on occasion.
Though not as widely grown as desert willow, chitalpa (scientifically known as X Chitalpa tashkentensis) has a lot going for it. For one thing, it appears to be more tolerant of poorly drained soils than desert willow, and it produces larger, orchid-like flowers. Its floral display begins in May or June and extends until frost, unlike the once-in-the-spring-flowering catalpa. Chitalpa flowers are borne in large clusters, each containing 15- to 40-inch-long florets that attract butterflies, bees and hummingbirds.

Chitalpa is a fast-growing, multi-trunked deciduous tree that branches near the base and creates an oval canopy. It has an open limb structure, allowing filtered sun to pass through and grass to grow beneath. Its desert willow-like, glossy green leaves are about 1 inch wide and can grow up to 6 inches long."



  1. We have a few desert willows here in Houston, but many more in El Paso!
    My plants are starting to wake up and things seem hopeful even after the severe freeze.
    Thanks for stopping by!
    These are some fantastic blooms. I had no idea Chitalpa was so beautiful up close.
    David/ Tropical Texana/ Houston

  2. I'd like to add a note here for people asking about why their chitalpa trunk splits or cracks. I asked the same question when it happened to me and the answer I got was that this was typical with this tree as it was a hybrid. So while some think it's perfection, others may disagree after their trunk splits. My tree seems to be fine now, but that was an issue with this tree for several gardeners. If it isn't severe, don't worry and just let it be for now.

  3. I was able to find chitalpas here in Tucson at Arizona Growers Nursery. They had a fantastic price. Only $45 for a 15 gallon! Everyone else was at $90. I planted 3 to replace my Acacia salignas that were severely damaged by the winter. Thanks for turning me on to these trees. I think they'll work out great.

  4. Always interesting to place unfamiliar plants in families. No wonder yours look sort of familiar - Podranea (Zimbabwe creeper) has similar flowers. Tecomaria with smaller flowers. And exotic jacaranda planted as street trees especially in Pretoria.

  5. We have a chitalpa in our back yard in Las Cruces, New Mexico. We moved here about 1-1/2 years ago, and the tree doesn't appear to be doing very well. As mentioned above, the bark is splitting and peeling, and many of the leaves are looking somewhat curled and burned. I was told by a landscaper here that deep watering, and feeding, would help. I did deep watering by using a 5 gallon bucket with holes in the bottom so that it leached slowly into the soil, about half way out from the trunk to the drip line. The spacing of the bucket for watering was about 2-3 feet. Does this sound about right, or do you recommend something different. And, how often should I do the deep watering? Any recommendations for feeding? Thanks!

    1. This is a hard one. Las Cruces is at a higher elevation and it gets a little cooler. It does well in full sun. A regular drip would be good for the first two years. Make a dirt well around the tree and fill it up every couple of day in full sun. The leaves will drop in winter. Still water that first year in winter. The bark does split and that is the problem with this tree. Deep watering and some tree fertilizer will help. With my trees, I have found shade to be the ultimate enemy as the tree needs that direct sun with water to support.

    2. And good luck! Let me know how it goes.


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