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Plants from the Ground Up

Robinia – A Tough Beauty

Robinias are some of the most beautiful trees, but like many beautiful things they may prove hard to tame.  With so many cultivars available, these trees have become a much loved garden plant all over the US and Europe. Robinia pseudoacacia was introduced into Europe in the early 17th century. One of the most amazing examples of this pretty flowering tree is the old gnarled Black Locust planted at Kew Royal Botanic Gardens in 1762! Click here to see Kew‘s ‘Old Lions’.

Robinia Casque Rouge - Pink Cascade Black Locust

Robinia Casque Rouge – Pink Cascade Black Locust

Robinia pseudoacacia has long hanging clusters of deliciously scented pea-like blossoms. The small highway I drive every day heading to the farm has a section that is lined with Black Locust trees. One of my favorite parts of spring is driving through that tunnel of perfume. I anticipate it long before I get there and I truly savor that bit of spring every time I drive through. These flowers are white on the native tree, but can be glorious shades of pink on some select cultivars. Other cultivars have interesting foliage such as ‘Uniflora’ which has a single leaf rather than the usual compound leaves, or ‘Frisia’ a glowing gold-leaved form. In autumn these trees are showy, becoming a lovely butter-yellow.

Robinia pseudoacacia Semperflorens - Black Locust

Robinia pseudoacacia Semperflorens – Black Locust

Commonly known as Black Locust, these fast-growing deciduous trees are native to North America. They are incredibly adaptable to tough sites and can grow in dry sandy soils. This toughness can also lead to them being invasive. Black Locust trees send up many suckers (even grafted varieties) that must be removed if spreading is not desired. They can also spread by seed and care must be taken to remove any unwanted seedlings. Despite their potential invasiveness, they are an incredibly useful tree. They are much loved by pollinators and honeybees (Robinia makes a delicious honey). Black Locust is a wonderful timber tree that can be coppiced for both firewood and cord wood building and is also good for erosion control. Robinia tolerate dry, difficult sites and can thrive in conditions that will not support other trees. Being a leguminous tree (of the pea and bean family) they fix their own nitrogen, a very neat trick! Another of my personal favorite things about this tree is that the flowers are edible. To make delicious Robinia flower fritters see the recipe below:

Robinia Flower Fritters

Any of your favorite batters will do, even beer batter!

You will need:

4 cups of Robinia flowers on the stem


2 cups flour

1 tsp salt

4 Tbl sugar

4 tsp baking powder

2 eggs

2 cups milk

Heat a neutral flavored oil in a skillet, dip the blossoms in batter and fry until browned on both sides. Sprinkle with fresh orange juice or powdered sugar.


Robinia pseudoacacia Semperflorens - Flower

Robinia pseudoacacia Semperflorens – Flower

Depending on the cultivar locust trees can range between 15-40′. They can be kept smaller with pruning, but as these grow very quickly that can be hard to keep up with. Pruning is spring is not recommended since the trees tend to bleed.

Robinia pseudoacacia has been bred with R. hispida and R. ambigua to create lovely cultivars like ‘Casque Rouge’. These cultivars may not be as cold hardy as the straight species. Black Locust can easily grown from seed, cultivars must be grafted. 

Robinia pseudoacacia is exceptionally cold hardy and can be grown to USDA hardiness zone 3.

For more photos and information, see Robinia at the Forestfarm Store.

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