Why Do Roses Have Thorns? A Fascinating Look into Nature
Roses are beautiful shrubs and climbing vines known for their exquisite, fragrant flowers. However, roses are just as well-known for their sharp, prickly thorns. While these thorns can be a nuisance for gardeners, they actually have several functions. In this article, I’ll run through everything you need to know about why roses have thorns.
What Are Rose Thorns?
Technically called prickles, rose thorns are sharp barbs that cover the plant’s woody stems. Prickles are slightly different from true thorns or spines, which are similar structures employed by other plants.
Prickles are downward-curving barbs formed from the same epidermal cells as the stem. This downward curve means that grazing animals can’t pull the prickles off the stems, exposing the plant.
Thorns are sharp, straight barbs that are actually specialized branches that can be single or branched. Spines are backward-pointing barbs that usually grow on cacti. Spines are designed to get caught on intruding animals and are difficult and painful to remove.
Why Do Roses Have Thorns?
Rose thorns are a defense mechanism, first and foremost. These sharp barbs line the woody stems, protecting them from grazing animals or insects. Rose thorns are hooked, so they can’t be pulled off. After a few exploratory bites, most animals learn to avoid trying to eat roses.
Rose thorns are also used as a climbing aid for some types of roses. Climbing and rambling roses are woody climbing vines that need growing support. Wild roses use other plants and trees as supports, which is where the thorns come in.
Climbing and rambling roses use their thorns to anchor themselves to other plants or trees (there are some types of thornless climbing roses if preferred). This allows the rose to climb higher and get more sunlight, helping it grow. This doesn’t usually damage the other plant as the thorns are strong enough to pierce bark.
How to Protect Yourself from Rose Thorns
Rose thorns help protect your roses from grazing animals, but they can be a nuisance for gardeners. If you try and work on your rose without protection, you’ll end up getting pricked by the thorns. This is especially true during seasonal pruning or when you’re harvesting cut flowers.
I like to use thick, good-quality gardening gloves to protect myself from rose thorns. This allows me to hold the stems without fear of getting pricked. I also like to wear a long-sleeved top made from a relatively thick material to protect my arms.
Removing thorns from roses is reasonably easy if you use a sharp knife and run it gently along each stem. This can be a good option if you have to work around your roses a lot on other plants. Some rose cultivars have also been bred not to grow thorns, so it’s worth bearing these in mind.
Although you can remove rose thorns, I prefer not to. Once you’ve removed the thorns, they won’t grow back. This can leave your rose vulnerable to insects and grazing animals.
10 Fun Facts About Rose Thorns:
- The primary function of rose thorns is to protect the plant from predators. They discourage animals and humans from touching or eating the plant.
- Technically speaking, rose thorns are called “prickles.” Prickles are sharp outgrowths from the plant’s epidermis, or outer layer of cells, whereas thorns are modified stems.
- Some climbing roses use their prickles to assist in anchoring themselves to other plants or structures as they grow upwards. This allows them to get more sunlight and spread their blooms in summer.
- The size and shape of rose prickles can vary widely. Some have fine, hair-like prickles, while others have large, hook-shaped prickles. The variety often depends on the species of the rose.
- Scientists have found that specific genes in roses control the formation of prickles. This genetic factor contributes to the different prickle characteristics seen in various rose species.
- Rose prickles can sometimes cause infections if they break the skin. This is because the prickles can carry bacteria or fungi that harm humans.
- The presence of prickles can help identify fossilized roses. Fossil records show that roses have had prickles for at least 35 million years!
- Some cultivated roses have been bred to have few or no prickles. These are often more popular in domestic gardens, where people are more likely to come into contact with the plants.
- The prickles on a rose stem can help channel water downwards towards the roots when it rains. This is especially beneficial in drier climates, assisting roses to survive.
- In literature and symbolic traditions, rose thorns (or prickles) often represent the pain and challenges that come with beauty or love. This can be seen in many stories, poems, and artworks.
Why Roses Have Thorns FAQs:
What Purpose Do Rose Thorns Serve?
Rose thorns are mainly used for defensive purposes to protect roses from grazing animals. However, rose thorns also act as a climbing aid for climbing or rambling roses.
Do Roses Have to Have Thorns?
While most roses have thorns, some cultivars have been bred not to grow these barbed prickles. These cultivars are known as thornless roses.
What Happens if You Cut Thorns Off Roses?
Cutting thorns off your roses shouldn’t cause permanent damage. However, the thorns won’t grow back. This can leave your rose vulnerable to grazing animals.
Wrapping Up
Roses use the thorns on their woody stems to protect themselves from insects and grazing animals. Although known as thorns, these spiny protrusions are actually prickles. Climbing and rambling roses also use their thorns as a climbing aid. Using their thorns, these roses climb higher to get more sunlight.
For more, see our in-depth guide on where to plant roses in your garden, and whether roses will bloom indoors.