Plant Defenses

When we look at a pretty flower sitting on top of a thin, green stem, we don’t usually think of them as being strong or tough, do we?

No, we think of them as fragile and pretty and we are careful not to tear its leaves or petals.

We should treat plants with care and respect.

But guess what?

Many plants are actually tougher than they look when it comes to protecting themselves against animals.

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Roses, blackberries, thistles, black locusts trees, and barberry shrubs are just a few of the many plants that have thorns to protect them from being eaten or damaged by animals.

We all know how pretty roses are and how good they smell, but roses are not very good at keeping themselves well if they get too wet, too cold or if animals try to rub on their branches or eat their flowers.

By using their horns to scare off animals from eating them, roses are able to grow bigger and prettier every year.


Have you ever been poked by a cactus? It’s not very fun, is it? Cactus plants are covered with spines that poke you when you come too close. Some are so tiny it is hard to see them when they get stuck in your skin. Others are big and sharp—almost like a needle. No matter what they look like, though, the ‘pokies’ on a cactus hurt. But they also keep it alive.

Cactus plants grow in the hot, dry desert. The animals living in the desert would like to drink the water and juices cactuses are filled with. But cactuses don’t want to be ripped apart by hot, thirsty animals, so they use their spines to scare them off.


Some plants have thick, hairy fibers covering their leaves. The hair is so thick that bugs cannot get through it to eat the plant’s leaves. The hairs also help the leaves of the plant hold and store water so they can survive in hot, dry places. The Panda Plant and Lamb’s Ear are two plants that protect themselves like this with their hairy leaves.

Juicy stuff

A large number of plants have a liquid (juicy stuff) in their leaves and stems that protect them from animals and insects. Some plants use their juicy stuff to poison animals and bugs that try to eat them. Other plants use it to cover themselves when ‘attacked’.

And still, other plants, like poison ivy, release oil when touched or harmed that make people and some animals break out in an itchy rash.

Poison ivy is only one kind of plant that uses liquid to protect itself. Some of the other plants that do this are:

  • Sugar beets
  • Molasses
  • Aloe
  • Willow trees


Who likes tomatoes? They taste pretty good, don’t they? But have you ever tasted a leaf from a tomato plant? YUK! Don’t do it.

Tomato plants are just one of the many plants that are safe from being eaten by animals because they taste so bad.

Bugs are tougher than plants

Bugs aren’t afraid of thorns and spines or yucky-tasting leaves and juicy stuff. In fact, they like it! Bugs can eat leaves off plants and trees quickly and can hurt or even kill them in a very short amount of time. That is why it is so important for people to do what they can to protect the plants and trees they grow and that are growing in their yards. That means you, too! Here’s how you can help:

  • Keep your plants healthy and well-fed. By keeping your plants watered, giving them the sunshine they need, and by keeping the soil fertilized you will give them a better chance to fight off bugs.
  • Watch your plants. Check your plants for bugs. If you find them, pick them off and kill them.
  • Keep your plants ‘clean’. Spraying plants with soapy water or other bug-killers will help keep bugs away.
  • Invite ‘good bugs’. Ladybugs are the most common ‘good bug’. Ladybugs don’t eat plants…they eat other bugs, so by releasing ladybugs into your garden, you will be feeding the ladybugs and saving your plants.

Check your plants

Check the plants and trees in your yard. Look for bugs, brown or yellow spots on the leaves, curled leaves and stems or bark that looks like it has been chewed.

Look for bugs hiding under leaves and in the bark of trees. Ask your parents to help you get rid of the bugs that are eating your plants.