Catalpa and Paulownia

Catalpa bignonioides. Le.Loup.Gris. Wikimedia Commons.

There are many copycats in the plant world, between plant families in particular, but also those outside. Both Paulownia and Catalpa share a similar look, growth habit, and flower shape- which is why I decided to lump the two together in one post. Oh and their fragrances are nearly identical as well. They are in different plant families and come from different areas, but with similar ecoregions.

Lets start with Catalpas. Catalpa is native to the Eastern U.S. and Caribbean, with a few species in Asia as well. The trees grow up to sixty feet and have large, heart-shaped leaves, and large, foxglove-like flowers. The flowers are followed by long, cigar-shaped bean pods. The wood of the tree is soft and branches rather brittle. The tree makes a wonderful specimen planting for its showy nature, but the seed pods are difficult to clean up after winter.

The two American species are the most popularly planted. C. bignonioides is the Southern Catalpa, native to central Alabama, but planted largely throughout the Eastern U.S. C. speciosa, the Northern Catalpa, is native to the Mississippi and Ohio river confluence region, but is also widely grown throughout the Eastern U.S. The trees are identical, save for the Northern Catalpa is less floriferous, but has larger, and more fragrant flowers. Northern Catalpa is also slightly more hardy, but both are hardy to zone 5. The fragrance is described as being sweet-pea like, but I tend to think it more on a jasmine side. In either case, it is sweet, but a fragrance that does not lend itself to spreading through air. The trees bloom from May to June, maybe as early as April in zones 8-9, and as late as July in zone 5.

Paulownia tomentosa. Famartin. Wikimedia Commons.

Paulownia, or Princess tree, is a stately tree in a landscape, but is unfortunately invasive in the Southeastern U.S. One drive down Interstate 75 from London, Kentucky to Knoxville, Tennessee is enough to verify this. It is another Asian native, with cultural significance in China and Japan, where the Genus originates. Paulownia is nearly identical to Catalpa, but grows larger, and flowers earlier in spring, with purple flowers that are larger than Catalpa blooms. The winged seeds come in egg-shaped capsules born after flower dessication. The trees have this distinction of producing extremely large leaves when in its early-growth stages, or after the tree is cut back. In these years, the tree does not flower.

The flowers are a light lavender color, blooming in mid-to-late April and early May for two weeks (Catalpa blooms later in the season for much longer). The fragrance takes a cue from Catalpa, but throws in a strong vanilla fragrance to boot, and unlike Catalpa, generously fills the garden with its scent. The wood from Paulownia has a strong significance in Japanese art as well, and is one of more the more utilized woods for crates and chests, as it is very light and workable, much like Catalpa. Lastly, it does have agroforestry uses, but is best in its home range in China and Japan.

If one were to compare the use of the trees side-by-side, its best to air with Catalpa in the states, as its native to the region, and has more colorful flowers.

Well May has come to and end, and I’m sad about how many plants I didn’t get to this month but there is always the future right? Tomorrow will be a post about the wonderful month of June and what plants to expect then!

 

Black Locust and Honey Locust

Robinia psuedoacacia. http://foragedfoodie.blogspot.com.

If I had been smart, I would have followed up my post about Wisteria with these next two blooming trees, as they are all in the same family, the Legumes. Black locust and honey locust, while very similar are also very different, even though they bloom at the same time, and for the same period of time, and have similar enough names. They are both also native to the Eastern United States, and are wild in my native Bluegrass Region of Kentucky. The trees make popular landscape trees, although black locust is favored for fence rows in the country and on farms, while honey locust is best known as an urban standard.

When you consider the difference between the trees, they are night and day. For instance, Black Locust is taller, has dark gray bark that is very furrowed with age, has larger pinnate leaves, and beautiful, hanging, white flower panicles. The flowers are almost like the white Wisteria flowers, although the racemes are much smaller, and the scent more similar to orange blossoms than grape. They also can be used for honey making, ironic considering the honey locust flowers cannot be. Honey locust grow faster and are shorter lived than black locust, have edible seeds, strongly thorny trunks and branches, (see below) yet otherwise smooth trunk and branches, and the flowers are rather inconspicuous. Honey locusts planted in urban settings are usually the thornless variety, for obvious reasons.

Gleditsia triacanthos. http://www.arborday.org.

Gleditsia triacanthos flowers up close. Andrew Butko. http://www.gardentaining.com.

If anything could make these plants any more different, it is certainly related to their scents. While both are very, very fragrant, they have an entirely different fragrance from each other. Black locust flowers are sweetly fragrant of orange blossom honey, and the scent carries best in warm humid weather on a south breeze. Honey locust flowers on the other hand, are ambrosia. If I had to describe the fragrance, its like tupelo honey sweetened with rose otto. Its strongly sweet and rosy, like a good rose incense, which is a strange scent to come by in any plant except rose. Its a fragrance one could spend a whole afternoon bathed in, as it permeates the garden and fills the countrysides and towns with a wonderful rosy sweetness.

To me, honey locust is the smell of May, along with peonies and Irises. Honey locusts tend to spill forth their perfume by the bright of day, with the honey releasing its sweetness by heat and sunshine, being strongest in the late afternoon and early evening. I’m not quite sure who the main pollinators are, or if its merely the wind. Speaking of wind, catching it on a warm breeze is a must for the nose, the scent of the flower on hand is completely different than on the breeze, and the atmosphere seems to bring the scent out much better.

The two plants together are the latest plants to leaf out each spring as far as I have observed. At least among wild plants and trees, they seem to get a late start in the foliage department, even if their flower displays are followed close behind leaf out and over with in a week or two. Although identifying the trees without foliage may be the funnest part given the uniqueness of the thorns on the honey locust. I don’t ever advise meeting one of these out in the few woods surrounding the bluegrass region, they are quite painful to run into, and the thorns can grow to be three to seven pronged and eight inches long! The pictures are no exaggeration, they belong to the cruelest of plants in the world along with their cousins the Acacias!

Gleditsia triacanthos. http://mosurvival.blogspot.com.

 Lastly, the wood of both varieties is excellent for woodworking and railroad posts. Black locust wood is used for everything from timber to flooring, and the thorns of honey locusts for nails. The wood takes more than one hundred years to break down and makes some of the best and hottest burning firewood there is. While black locust is native to the Eastern United States, it is grown over large parts of Europe and Asia for its ornamental value and usefulness of its wood, and is invasive in parts of both regions. Both have the capacity for nitrogen fixation and soil renewal regardless and are a valuable tree for permaculture purposes.