The wind is no problem for this evergreen bloomer. Middle-aged 'Purple Robe' Black Locust. Some confusion exists over the nomenclature of this plant. However, purple locusts will not tolerate "wet feet" and therefore require good drainage. Scientific names: Robinia pseudo-acacia. *If you have found your zone already, it will be highlighted in the table below. Purple Robe Locust trees develop incredible, long clusters of purple colored flowers in mid- to late spring that look very much like Wisteria flowers. Black locusts have invasive traits that enable them to spread aggressively. Seed pods, or legumes, mature in early fall. 2. These showy flowers grow on reddish-purple branches that have spikes at their base. We ALWAYS sell out of this incredible native tree and this year will be no exception. Purple Robe' locust: 35 x 25. Show Approximate Ship Dates & Restrictions, .18 to .21 dry quarts / .198 to .23 dry liters in volume, .31 to .87 / .35 to .96 dry liter in volume, 1.4 dry quarts / 1.59 dry liters in volume, 1.89 of a dry quart / 2.08 dry liters in volume, .8 to 1.1 dry quarts / .88 to 1.2 dry liters in volume, 1.0 to 1.3 dry quarts / 1.1 to 1.41 dry liters in volume, 1.1 to 2.1 dry quarts / 1.2 to 2.3 dry liters in volume, 1.7 to 2.3 dry quart / 1.87 to 2.53 dry liters in volume, 2.26 to 3.73 dry quarts / 2.49 to 4.11 dry liters in volume, 3.5 to 4.3 dry quarts / 3.85 to 4.74 dry liters in volume, 1.19 to 1.76 dry gallons / 5.24 to 7.75 dry liters in volume, 2.32 to 2.76 dry gallons / 10.22 to 12.16 dry liters in volume, 2.92 to 4.62 dry gallons / 12.86 to 20.35 dry liters in volume, 5.98 to 6.08 dry gallons / 26.34 to 26.78 dry liters in volume, Fragrant, Wisteria-like Purple Flower Clusters. Note, though, that you have to pick the honey locust tree for this as the pods of black locust are toxic. It thrives in many difficult growing conditions. The purple robe locust tree is a medium-sized tree, growing to heights between 30 and 50 feet and widths between 25 and 30 feet at maturity. Two of the most famous types are the honey locust trees (Gleditsia triacanthos) and the black locust trees (Robinia pseudoacacia). Common names: false acacia, robinia. The wood of black locusts is also very sturdy. The thorns grow on branches at the base of a cluster of leaves, so it would be easy for an animal to eat the thorns while also taking a bite of leaves. How to Use Purple Robe Locust in the Landscape. 'Purple Robe' Black Locust1 Edward F. Gilman and Dennis G. Watson2 INTRODUCTION This cultivar of Black Locust probably grows to about 40 feet tall with a spread of 20 to 35 feet (Fig. Black locust trees grow to between 40 and 100 ft. (12 30 m) with exceptional varieties reaching heights of 171 ft. (52 m). One more distinctive feature of the black locusts is their oblong crown, which you can see atop its straight trunk. It will die back to the ground when the weather turns cold, regrowing when the weather is more favorable. In fall, the fern-like foliage turns a beautiful yellow color, similar to all types of locust trees. Robinia is a genus of between maybe 6 to 30 species (many are unresolved) of trees and shrubs from North America. Fixes nitrogen. The leaves will show an impressively rich shade of bright yellow when the fall comes. Once your order is placed, you will also receive the specific shipment time-frame information as part of your order confirmation. Its leaves are typically bronze-green, turning bronze-red in the spring . Expect them to look green at first then become red and lastly, brown. It is an impressive display, and you will definitely want to cut a few and bring them indoors to enjoy in a cut flower arrangement. Once the flowers bloom, long pods will follow. It also has bright green and feather-like leaves. There are several cultivars of thornless honey locust trees, such as Imperial (Impcole), Skyline (Skycole), Sunburst (suncole), Moraine, Northern Acclaim (Harve), Perfection (Wandell) and Street Keeper (Draves). The highly distinctive ferny structure with up to 45-feet growth and 25-feet spread of the skyline honey locust tree is one of the things that makes it so appealing to many people. 5. Generally, you can find two major locust trees: the black locust tree with the scientific name Robinia pseudoacacia and the honey locust tree with the scientific name Gleditsia triacanthos. The flower color helps to tell black locusts apart from honey locust trees that have creamy-green colored flowers. Keep in mind, specific varieties and different growing conditions can affect the rate at which plants grow. It's also a hardy choice for tough environments, like urban areas. Start Growing Squash In Your Garden Planting and Caring Tips, Growing Swiss Chard Planting, Harvesting, Growing Guide, Growing Turnips Grow, Plant, and Harvest Guide, Growing and Planting Mustard Greens Guide, Growing Mushrooms at Home and Garden to Eat, Growing Broccoli What You Need to Successfully Grow Broccoli, Okra Companion Plants What Plants Goes Well with Okra, Arugula Companion Plants Guide to Growing Friends, Guide Planting, Harvesting, and Growing Scallions, The Spring's Trumpet: The Magic of Daffodil -- Magical Herbs, Plants Ideas That Thrive in Closed and Open Terrarium, Asparagus Companion Plants What You Can Grow and Can Not. The Garden wouldn't be the Garden without our Members, Donors and Volunteers. You can count on this bloomer to show off all summer long in raised beds, containers, or directly in the ground. Do you know that black locust trees are also effective in producing honey? Our horticultural team has put together recommendations on how to best use this tree in your landscape: 1. Purple Robe Locust trees are very hard wooded and will tolerate storms well. Javelina and rabbit proof, this bloomer is a must-have. Arizona plant. This cultivar has yellow foliage and grows 40 feet high by 25 feet wide. It forms an oval-upright canopy. Black locust is resistant to black walnut toxicity. To grow this locust tree variety, ensure to provide it with full sunlight and moist but well-drained soil. 1. I have two purple robe and one golden locust that we planted when we moved in ten years ago. Sunshine Geraniums make gardening brighter! At 20 feet high by 20 feet wide, this tree is smaller in size and has contorted limbs. with rather open and sparse-branching habit. The honey locust has clusters of small, creamy-green flowers that bloom in late spring and early summer. The honey locust tree has a wide canopy and this helps grass to grow in its shade. For the best experience on our site, be sure to turn on Javascript in your browser. Previous Post: Farewell to Roses. Purple-robe locust trees need full sun, although they will tolerate light shade. The purple robe locust tree is also very thorny and has relatively weaker wood than the others. When planning to grow the sunburst honey locust tree, remember that it requires deep watering and pruning during the winter. Popular sizes of select trees are 1 foot, 2 feet, 3 feet, etc. Violet purple spring flowers make this an interesting tree for the landscape. Order today! These showy flowers have an intense fragrance meaning the bristly locust tree attracts honey bees and other pollinators. The dark gray bark is deeply ridged and furrowed with a rough, scaly, or ropy texture. Pictures, descriptions, and their scientific names will help identify each species of these deciduous trees. Bright green foliage turns a beautiful yellow color in the fall. The purple robe locust is hardy in U.S. Department of Agriculture zones 4 to 8. It derived its name from the fact that it indeed has no thorns at the twigs and barks, making it distinguishable from other honey locust trees. Help trees thrive in the Chicago region and around the world. The new foliage emerges tinged with purple and matures to a bronze-green color. Purple Robe Black Locusts make great street trees, too, handling the tough conditions by your road with ease. They eventually mature to a dark green and turn yellow in the fall. There are many reasons why the Suncole cultivar is popular in landscape gardens. They are growing beautifully without any care in poor soils, with open exposure, and where little additional water would ever get to them? Fragrant wisteria-like violet purple flowers in pendant racemes (to 8 long) bloom in mid to late spring. Trees send out underground root suckers that not only become a maintenance problem but also can disrupt nearby gardening areas. The pulp on the pods is the one edible and can be consumed by livestock and wildlife. The perfect cottage garden flower ideally grown in containers, hanging baskets, or raised beds. Walk around each locust tree in your landscape to look for shoots coming up at the base of the trees. Beanlike, 4 inches (10.2cm) pods turn brown and . The New Mexico locust tree also boasts an average growth of 10 feet. It is short-lived and prone to borer injury. Black locust thorns are not bad, 1/2" at most, and they are really only on the new growth, as the branch gets bigger they loose the thorns. Locust trees are fast-growing flowering trees that belong to a family of flowering plants called Fabaceae. RMG334R5 - Robinia pseudoacadia 'Purple Robe' Purple Robe Locust RM FGARG8 - nierembergia hippomanica purple robe Cupflower flower flowers flowering Caerulea var violacea groundcover RM Floral RF 2J07AG9 - Passion And Crucifixion Of Jesus - Crown Of Thorns And Bloody Nails And Purple Robe On Ground With Sunlight And Selective Focus Just like the black locust, the species of honey locust grows in many different environments and thrives in full sun. The honey locust tree is a hardy, fast-growing tree, similar to the black locust tree. Clusters of heavily scented pink-purple flowers dangle from the locust tree, filling your garden with spring colors. Anyone interested in growing trees can make it part of their plant or tree collection, allowing them to witness a spreading canopy capable of providing a nice spot with shade. Rose, Pink to white flowers cover this spring bloomer that often repeat blooms in fall. Known for being an easy tree to care for, the Purple Robe Locust is a hardwood variety that makes a great street tree. Leaves emerge an interesting bronze-red in spring, but eventually turn an uneventful yellow in fall. Different to honey locust trees, the sharp spikes are short and dont grow in long branches around the tree. Don't plant it too deep, as is key for any new tree. Its the perfect summer shade tree. The black locust is kind of invasive and features twenty-one leaflets less than two inches long. Note that various locust tree species also grow healthily in the wild, especially in North America. Other names for the New Mexico Locust tree include Desert Locust, Pink Locust, or Rose Locust tree. It can also spread to around 20 to 35 feet. While many say that locust trees are poisonous, you should still remember that not all of them are toxic and poisonous. Purple-pink pendulous flowers provide plenty of color to a garden in late spring and early summer. Sharp spines may be present, especially on sucker growth. Chokecherry Tree: Leaves, Chokecherries, Flowers (With Pictures) Identification, Weeping Cherry Trees: Types and Care (Including Dwarf Weeping Cherry Trees), Flowering Dogwood Trees and Shrubs: Types, Leaves, Bark - Identification (With Pictures), The Best Desert Trees with Pictures and Names, Types of Locust Trees with Identification Guide and Pictures, Small or Dwarf Weeping Trees for Landscaping, Dwarf Fruit Trees to Grow Indoors or Outdoors. Combine that with the decorative shape of its branches, trunk, and foliage, and this tree will surely add a more aesthetic appeal to your garden. It looks elegant as it features arching leaves that radiate in clumps starting from a central point. Purple Robe is considered to be a very easy-to-grow tree. The spiky trunk is one reason why the tree is also called the thorny locust. Plant Sentry is designed to protect both consumers and the nursery trade from invasive plant pests and diseases. Other insect problems include caterpillars, weevils, scale and whiteflies. We literally can't keep this tree in stock! In general, honey locust trees are non-messy. Robinia pseudoacacia'Purple Robe' Figure 1. She proliferates up arbors, pergolas, fences, and stunning as a ground cover to retain hills. Purple robe black locust (Robinia pseudoacacia 'Purple Robe') It is considered as one of the most beautiful locust trees because its leaves change in every growth stage. The leaves on locust trees are feather-like and pinnately shaped and measure 6 to 14 (15 36 cm). Fragrant, Wisteria-like Purple Flower Clusters. An easy-care, fast-growing specimen in lawns. The purple locust tree is a member of the legume family, which means that it can fix soil nitrogen, which allows it to survive in sandy soils. She loves the heat and super drought hardy. To obtain a more accurate shipment time-frame, simply enter your zip code in the Find Your Growing Zone box to the right. It's become incredibly popular because of the great purple flower color and excellent fragrance. The fern-like leaves and widely spaced branches give enough shade without completely blocking out sunlight. Incredible, long clusters of purple flowers in May that look just like Wisteria flowers hanging from this local bloomer. Entire leaf is 6 to 14 inches long. The feather-like leaves are pinnately compound that are bright green throughout spring and summer before turning to golden yellow in the fall. This variety has the term inermis which means that the Sunburst honey locust is a thornless tree. Common names: Like many types of honey locust trees, the bark is gray-brown. Michael Dirr (p. 1014, 2009) calls it an "alley cat" type tree which can survive under the toughest conditions. These beautifully fragrant clusters cover the tree profusely that grows up to eight inches long each! Purple-robe locust trees grow at a fast rate of 2 to 3 feet per year, reaching a mature height of 40 to 50 feet, with a spread of up to 30 feet. Because of its thick and large branches, you can also easily distinguish the New Mexico locust tree. Purple Robe Locust Mirazroa/Shutterstock This purple flowering tree is mainly found in North America, but don't let the pretty flowers fool you. Leaves on the skyline honey locust tree are pinnate or bipinnate containing pairs of small, ovate leaflets. The most common types of locust trees are the black locust and honey locust tree. Cut a few of these flowers and enjoy them in an indoor vase, as it is an impressive display. The roots and seeds of the purple robe tree spread so aggressively that it is considered invasive. Expect it to grow straight then branch off eventually with elegance and balance to form big fronds of foliage capable of arching and drooping once the generous and rich flowers with nice scents start enveloping them with the shade of white. As a guide in growing this famous locust tree, take note of the following: As for its size, expect this tree to grow around 30 to 50 feet high. Good drought tolerance. Flowering Shrubs. Compared to the black locust, the honey locust trees flowers arent as showy and stunning. 5. The tree can grow up to 75 ft. (22 m) tall and provide shade up to 40 ft. (12 m) wide. You will also notice the black locust blooming prolifically even if some of its varieties dont bloom annually. As the tears of sorrow fell upon his face. Grow in average, dry to medium, well-drained soils in full sun. Aside from the possibility of the thorns poisoning those who come in contact with them (though, this is just rare), the tree is also kind of invasive, so learning how to control its spread and rapid growth is also sometimes necessary. Additionally, 'Purple Robe' is incredibly tough, super hardy, and drought tolerant. Leaves and stem. Bees produce a delicious honey from the flowers. Extremely fragrant and only found locally at Watters. Middle-aged 'Purple Robe' Black Locust. Note, though, that controlling various locust species is a bit difficult. 5. We are a team of writers that love all things plants. Purple Robe Locust Tree (Robinia pseudoacacia 'Purple Robe') is an improvement of the native Black Locust tree. However, the dappled sunlight means that plants that need partial shade grow well in its shadow. Make a great street tree, handling the tough conditions with ease. Note, though, that it also depends on how you define messy. Each leaf is divided into anywhere from nine to 17 leaflets that are 1 or 2 inches long and arranged in pairs. They clothe him with purple ( ).So also says St. John (John 21:2, ).St. Popular sizes of select bare root plants is 1 foot, 18 inches, etc. M. Compound leaves emerge with purple tint. Purple robe black locust (Robinia pseudoacacia 'Purple Robe'): The flowers on this tree are deep rosy-purple. They are also susceptible to locust borers. The Purple Robe has beautiful aesthetics because of its purple flowers. The fruits are flat brown legumes (pods) and are 4 inches long. The black locust tree bark is not sharp and thorny like the honey locust tree. Danielle November 13, 2007, 9:35 am. Other names for the bristly locust tree include rose-acacia and moss locust. Honey locust can also produce the heaviest and largest pods around ten to eighteen inches long and one inch wide. Promptly remove suckers as they appear unless naturalization is desired. This cultivar of black locust probably grows to about 40 feet tall with a spread of 20 to 35 feet. Due to winter weather we have put a hold on shipping to the areas shown below in grey. It thrives at a neutral level, too. Similar to the black honey locust tree, the bark on the New Mexico cultivar is light gray-brown with shallow furrows. It is commonly called the Sweet Bean, Sweet Locust and Honeyshuck. You can use the seed pods of locust trees as fodder for your livestock. This is a thornless and pod-less variety of locust tree with small leaflets meaning that it is easy to maintain. Hardy to zone 3, this locust prefers full sun, is tolerant of most soils and fixes nitrogen. This thorny tree also works well to control erosion. The trunk is long and straight with an interesting branching pattern. If you have the seedless and thornless variety of honey locusts, it is not that messy as the debris it drops over a short period every year is easy to clean. It is crucial to prune this tree during the summer and fall to ensure that it retains its pyramid-like shape. It grows fast as a shade tree and follows an arching habit, allowing it to showcase a shade of around 30 to 35 feet and a height of around 30 to 50 feet. Wait until late spring, when the flowers are done blooming, before making any cuts. Soil: Most soil types, including alkaline, acidic, and neutral It can thrive in salty soil, too, and can tolerate light drought and a bit of flooding. The bristly locust tree is a large flowering shrub with compound leaves, pink pea-like scented flowers, and reddish-brown seed pods. Lets look at various kinds of locust trees, starting with the two most popular speciesthe black locust tree and the honey locust tree. Black locust flowers picked from our favorite spot. For this reason, New Mexico honey locust trees are popular for garden landscapes in hot climates. Once established, this tree is super hardy and drought tolerant with a brisk growth rate of 2 or 3 feet of growth each year. His raiment was a scarlet purple robe. Presently, you can see these pulps being used in producing herbal tea. 3. Research has shown increases in nitrogen in barley grain crops interplanted with locust, and black walnuts interplanted with locust as "nurse" trees were shown to rapidly increase their growth. When you sign up for our FREE newsletter! Flowers white, fragrant, .5-.8 inches (1.3-2cm) long, in dense, hanging clusters 4-8 inches (10.2-20.3cm) long. This variety is relatively thornless, although the occasional thorn may be found. If you want a thornless variety of skyline locust tree, look for the Gleditsia triacanthos f. inermis Skycole cultivar. As with most types of honey locust trees, the skyline has a spiky trunk with thorned branches. Another distinguishing feature of the black locust is a pair of sharp and short spines where you can see its leaf being connected to the stem. Some also use the pulps of the seed pod to ferment beer. Identifying species of locust trees can be done by features such as their flowers, color of bark, height of the tree, and the thorns. Fall color is yellow-green. Overall, the black locust is also a fantastic hardwood tree capable of growing thick and tall. Dec 8, 2015. I fell in love last Thursday. Super hardy and drought tough with a brisk growth rate of 2 feet in one year. Black locust leaves are made up to 7-21 paired leaflets on both sides of a common stalk (pinnately compound). The upright, rounded growth and short, irregular In commerce, it is synonymous with and frequently sold as R. pseudoacacia Purple Robe. The attractive features of the Purple Robe locust tree are its young red leaves that turn to blue-green and then turn yellow in fall. In Illinois, it is native only to the far southern edge of the state. In any case free trees free trees, want more of the purple robe locusts! This tree is capable of blooming dense groups or clusters of flowers capable of attracting bees. It is advertised as thornless, but plants with thorns are found in commerce. This can give the tree an oriental or Japanese appeal despite being a native plant in the US. As he stood alone forsaken on that day. It has grown in to the neighbors yard, and he's allowed one to grow to a height of about 10 feet. It is famous for its ability to grow large clusters or groups of pea-like flowers that tend to bloom during the spring. Ecological threat: Invades forests, upland prairies and savannas, pastures, old fields and roadsides. Every backyard should have at least one. The trees bark is furrowed and so dark a gray that it looks almost black. Review of the risks should be undertaken before selecting these trees. As with any plant, proper site selection is key to success and to YOUR happiness. If you are planning to grow honey locust trees, take note of the following: You also have to consider its size upon reaching maturity before growing it, so you can provide it with the right amount of space for growth. Trees of the Purple Robe Locust develop long clusters of violet flowers similar to those of Wisteria in the spring. Robinia pseudoacacia, commonly known in its native territory as black locust, is a medium-sized hardwood deciduous tree, belonging to the tribe Robinieae of the legume family Fabaceae. The tree also features dark red to black and leathery seed pods that are around two to four inches in length. The pinnately compound leaves are also usually around seven to eight inches long. This is also a drought-tolerant tree capable of blooming fragrant white flowers. It is a common street tree and provides great shade. Growth Requirements. Almost any soil condition will do, including clay, sand or loam that is acidic to alkaline, with a preference for a pH ranging from about 6.8 to 7.7 and an organically rich loam. Overall, you will notice the Imperial honey locust showing off its ferny structure that has a tinge of yellow green. The wood is weak and brittle making it subject to storm damage. You can use this timber to manufacture fences and perform other services when it comes to carpentry. Its wide spread, lack of thorns, and pod-less characteristics mean it is not a messy tree. If you encounter issues loading this site, please refresh the page by using Ctrl + F5 if on Windows or Cmd + Shift + R if on Mac. This type of black locust tree thrives in states such as Colorado, Utah, Arizona, and New Mexico. Depending on the species, the locust leaf could be light green. The black locust tree is also very appealing that everyone will notice its presence in a park or garden. This fast-growing native tree can form colonies and has brittle wood. Similar to other cultivated honey locust trees, the 'Purple Robe' grows to between 30 and 40 ft. (9 - 12 m) tall and has a spread of up to 30 ft. (9 m) wide. This beautiful black locust tree is also incredibly attractive, with eye-catching aesthetics. Plant your small bristly locust tree in full sun and well-draining soil. This tree is distinguishable because it does not have thorns plus it grows really fast. Despite being an independent tree, growing this variety with other trees is also fine provided they are in big compositions. Black locust trees have thorns while honey locust trees are mostly thornless. The most widely used landscaping variety is the thornless honey locust with is beautiful white pendulum of blooms in early Summer and its graceful form as an attractive street tree in urban areas. The beauty of this mid-sized ornamental tree is that they can grow in just about any condition as long as the soil drains quickly after a rain. The earliest reports of possible poisoning associated with the black locust involved horses, which either became severely ill or died from swallowing parts of the tree. Once the flowers bloom, long pods will follow. The leaves on honey locust trees appear slightly earlier than on black locust trees. And the fact that it has thorns on its branches, makes it even worse! However, both the Robinia and Gleditsia species of locust trees have strongly scented blossoms. Black locust timber (left) and bark (right). In the common judgement hall, He was mocked and scorn by all. Blooms are often followed by showy, 4 purple edible fruit . Purple robe locust tree. You can also differentiate the two based on their benefits and uses and their identifying features and characteristics that you will learn in the next parts of this article. You wont want to miss any of the show. It can withstand high heat, full sun, acidic or alkaline soil, and urban pollution. Suggested Use: Street Tree, Flowering Tree, Naturalize. Due to orangey-red colors in the deep grooves, the bark may have an overall reddish appearance. Upright, spreading shrub with slender thorns, narrow silvery leaves, orange fruit on females persists into winter: Holodiscus dumosus Rock spirea: 4 x 4. You can often find the Gleditsia triacanthos form inermis or this thornless locust tree in suburban landscapes and cities. options as you create a beautiful landscape with help from Nature Hills. It is a good choice if you are in search of a thornless honey locust tree variety. Tolerates some light shade, but avoid shady locations. You can cultivate it to craft furniture in carpentry, which makes it different from the black locust. The native species blooms in mid-late spring and the flowers are white and fragrant. You will also notice their twisted pods in dark brown. It is susceptible to locust borer (often fatal) and locust leaf miner (browns foliage). There are no sharp spine or pods to clear up in the fall. I've grown 'Purple Robe' both on the Valley floor and in the mountains near Yosemite. The tree's flowers often stay blooming for longer than other varieties of black locust. The large compound leaves have smaller blue-green leaflets, and you'll love the fine-textured look of the tree in summer. These beautifully fragrant clusters cover the tree profusely and may be up to eight inches long each! But once established, tough Purple Robe Locust trees are also super hardy and drought tolerant with a brisk growth rate of 2 or 3 feet of growth each year. 1815 W. Iron Springs Road The bark, seed pods, branches, and leaves are considered to be toxic. The upright, rounded growth and short, irregular branches form a tighter canopy than the species and cast medium shade below the tree, allowing a lawn to grow. It is a strong tree that is adaptable and easy to grow while having the ability to resist various pests, insects, and diseases. Black Locust (Robinia pseudoacacia) Flowers. This small, tough native tree is prized for its fragrant purple panicles of flowers that appear from mid to late spring. The flowers on this tree are deep rosy-purple. It has a rapid growth rate and lives up to an average age of 100 years. Yes, the wood is brittle but as long as the tree gets some cold and They are usually about 2-4 inches long, flat, straight or slightly curved, and typically contain 3-10 seeds per pod. Your Cart. The flowers are important sources of food for honeybees. Purple Robe. The small flower clusters are a greenish-yellow color that provide color to your garden in late spring and early summer. You can pick them but be extra careful if the tree has thorns. Purple Robe Locust (Robinia pseudoacacia 'Purple Robe') is a medium-sized upright tree, growing 40 feet in height with a compact, rounded form. Note, though, that the purple robe locust tree has this invasive nature, which is why it is not ideal for household lawns. The leaves on black locust trees are pinnately compound and grow to about 10 (25 cm) long. Loam, wet . In the fall, the green leaves turn to a stunning bright yellow color. It's a medium-sized tree, reaching about 40 feet in height at maturity. The purple robe was to symbolize royalty, and they mocked him as King of the Jews. The purple locust tree can become infected with locust borers, which are black beetles with yellow markings that create tunnels inside the trunks and branches of the tree, weakening it. An impressive show and worthy of cutting a few flowers and bringing them indoors for enjoyment. Purple Robe Locust is a tremendous shade tree that develops long clusters of purple-colored flowers in May that resemble Wisteria flowers.