How to deal with tubers and bulbs, most amateur gardeners already know. But when it comes to the so-called rhizomes, some do not quite dare to experiment with them and use them, for example, to propagate the plant. If this is also the case for you, we will come to your aid. In today’s article, we will focus on these interesting parts of the plant. We’ll explain what they actually are, what the difference is between tuber, bulb and rhizome, and especially go into how to divide rhizomes.
Table of Contents
What is a rhizome?
Many believe that rhizomes are another kind of roots, so to speak, but this is not true. Actually, the rhizome is a shoot axis. This has the characteristic in itself that it does not grow above ground, as in other plants, but is located underground. However, in some types of plants with rhizomes, it also partially peeks out of the ground. When you replant a plant, you should keep this fact in mind. This type of sprouts also do not grow vertically as usual, but mostly horizontally. The actual roots as well as the above ground parts of the plant originate from this rhizome.
Difference between rhizome, bulb and tuber
A bulb is considered an underground shoot capable of storing nutrients and water for dormancy in winter, whereas the rhizome is an underground stem, so to speak, but serves the same purpose of being a storehouse. In addition, by dividing it, you can get new plants. Tubers are divided into shoot tubers (e.g. potatoes) and root tubers (e.g. dahlias). They can grow above ground (then called stem tubers – e.g. kohlrabi), as well as underground.
All three are overwintering organs that serve as storage.
Dividing rhizomes to propagate plants – how to do it properly?
Dividing the rhizome is not only suitable for propagation, but also rejuvenates the plant at the same time. We explain each step so that everything goes smoothly and you continue to have healthy and even new plants from now on. Do not worry, it’s really not as difficult as you might think.
Summer is usually the best time for dividing rhizomes. Therefore, you may as well get started. In August and late summer and until autumn, some perennials are divided, some of which also have rhizomes. Here’s how you should divide rhizomes (we’ll show you using a bearded iris, but the steps are the same for all plant species with rhizomes):
Dig up the plant
First, take a good look at your plant and note how deep its rhizomes currently lie. As mentioned earlier, for some, these must be partially above ground. The way your plant has been standing is the way you will need to replant it when you are done.
Take a fork and with its help carefully lift out the plant. To do this, pierce the soil at the outermost edge of the root ball, stick the fork deep enough, and lift the plant up, along with its rhizomes and roots. In some cases, it may be helpful to cut back the above-ground parts of the plant so they do not interfere, but it is not mandatory. In any case, it will reduce evaporation later after you plant the plants and also reduce the weight so the plant will have an easier time growing.
Then take the plant in hand and shake off excess soil only at first. Then continue with the garden hose: gently rinse the soil from the roots and rhizomes, so that you can divide the rhizomes more conveniently afterwards. This is because you will get a better overview.
Now you can divide the rhizomes
Now you can cut off the outer parts. Make sure they also have some roots, as well as a head of leaves, and use a sharp knife/garden shears to get a smooth cut.
While you’re in the process of cutting off the new parts for propagation, you might as well do some maintenance to keep your plant young. Namely, you should remove rhizomes that are already old and no longer have foliage. This is because they will no longer produce flowers. You should also remove those that are rotten or dried out. Also shorten longer roots to about a third of their length.
After you divide rhizomes, they need to dry out for at least a few hours, or better yet, a day. This will protect the cuttings from rotting later.
Planting the rhizome
After the time for drying has passed, you can replant the new parts and, of course, the old plant. Be sure to plant them in the same way they were before, that is, at the same depth.