Plant Types

Let’s talk about the different types of plants that you could put out in your yard or in a container on your patio. There are several different types of plant materials available: perennials, annuals, biennial, rhizomes, bulbs, corms, and tubers. What is the difference and why do we care anything about them? It is important to know about these different types of plants so you will know how to plant them properly and how often you will need to replace them.  The type of plant you purchase will also influence how you care for your it.



A perennial is a plant that grows for several years at a time from the same roots. There are both large perennials and small ones. For example, a tree is a perennial.  It grows off the same roots every year and you do not need to replace it on an annual basis. An example of a smaller perennial is a columbine.  Your columbines will die back to the ground at the end of the growing season, but will come back up the next year and grow and bloom.




An annual is a plant one that will is only viable for one growing season. It will die and will need to be replaced. Annuals can also be large or small. A sunflower is an example of a large annual that is usually grown that can be grown from a seed but it will not live beyond one growing season so must be planted again the next year. An example of a smaller annual is a pansy which grows well for one season then dies and does not come back up the next year. Often though, it seems as if they do come back up because they self-seed. That simply means that the plant’s seeds will drop near the plant and germinate without any outside help so new plants will come up the next growing season.




A biennial is a plant that takes two growing seasons to complete its life cycle. Biennials usually produce vegetative or green growth the first year and then flower and reproduce the next year. They can be large or small in size. Fox glove (digitalis) is a large biennial from the figwort family. It produces foliage the first season then dies back only to come back up the next growing season and bloom. Another example is hesperis, also known as sweet rocket, dame’s rocket and mother of the evening.  It grows nice soft green foliage the first season then blooms the next season.

Fox glove (digitalis) 


A rhizome is a fleshy, horizontal growing stem that is found at or near the surface of the ground (1). Rhizomes can grow to be large or small. Most rhizomes should not be planted very deep or they will not grow. Instead, place the rhizome just below the soil surface. Bamboo typically develop from a rhizome and will come up year after year in the right environment.  They are generally considered a tropical plant but some species do well in colder regions. An iris is another example of rhizomous plant.  Iris will come up every growing season, die back to the ground, then come back the next year. You can divide rhizomes easily if they become too crowded by simply cutting the rhizomes apart.






A bulb is a specialized underground storage structure that contains all the plant parts within thickened, fleshy scales. There are two types of bulbs – tunicate and non-tunicate. A tunicate bulb is characterized by layers of fleshy tissues (like an onion). Non-tunicate bulbs have scales that are fleshy and separate easily. A tulip is a tunicate bulb It will come up year after year, but eventually it will deplete the reserve food supply in the bulb and it need to be replaced. A bigger non-tunicate bulb is an Asiatic lily that will return year after year with very little maintenance required.


Tulip Bulb




A corm is the base of the stem that is swollen and is enclosed in a dry covering (1). Gladiolus grows from a corm. These garden favorites will grow well for a season but in colder areas, you must dig them back up, store them inside, and replant them the next year. A crocus grows from a corm but does not need to be lifted each season.  They are often the first flower to bloom in the spring and lend themselves well to naturalizing.





A tuber is a special kind of swollen underground stem that stores food for the plant (1). Most of you have seen a potato which is one type of tuber. There are also flowers that are tubers for example a dahlia is a tuber that ranges in height from 12 inches to 6 to eight feet tall. In colder areas, dahlias need to be dug in the fall and stored as they don’t do well in colder temperatures.  Digging them up and storing them will provide the gardener with many seasons of beautiful blooms.  Another example of  tubers are certain species of begonia, called (interestingly enough) tuberous begonias.  These  grow 8 to 10 inches tall and are well-suited for hanging baskets.

Potato Plant and tuber


The examples given for each category are only a few of the amazing array of plant material available for your gardening pleasure.



(1) Plant Propagation:  Principles and Practices by H.T. Hartmann, D.E. Kester, F.T. Davies, and R.L. Geneve, 7th Ed.



  1. holly said,

    April 15, 2008 at 1:05 pm

    I really love reading your blog I am so excited for spring so that I can stretch out my green thumb. I only have five plants right now including three spider plants. I find your blog informative and instructive. Thanks

  2. Calla Schoenecke said,

    April 15, 2008 at 1:09 pm

    This was another interesting blog post. I really like how you include pictures of the different flowers you talk about.

  3. tmurray said,

    April 15, 2008 at 1:09 pm

    This is a very interesting post, you seem to be very knowledgeable about plants and their life cycles. Im taking a plant biology course so I have some bacround as far as plants go but the class mostly just teaches plant anatomy. If i had to pick one of these to plant I would probably choose perennials, however, I might be better off with a cactus because i would probably forget to water them.

  4. Marianna Brandt said,

    April 23, 2008 at 5:47 am

    This is great information. Thank you.

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