If you plant bulbs or grow clumping perennials, you must divide the plants so they can remain healthy. It is in this manner that bulbs and some types of perennials reproduce, so if they are ignored for years the overall health of the plant can suffer. If you plan on dividing your plants as needed every year, you can keep the normal growth rate of your plants. Save some excess bulbs to give as gifts and you will be one of the most popular gardeners in the neighborhood.
Plants such as clumping perennials or bulbs multiply by growing away from their circumference and adding new stems and roots. After a few years of steady growth, the plant can become too large for its purpose. Oftentimes they grow so large that they overstep their proper place in the garden, pushing out other plants. Sometimes the plants crowd each other tightly for valuable nutrients for survival.
Since these conditions do not promote a healthy garden, at the first sign of these problems you should divide these plants. Every segment within clumping perennials is capable of creating an new plant, and every small bulb can be detached and planted far away from the adult plant.
Division is best done in early spring or late autumn, where there is no growth of the plant. Always wait until the plant is in a stage of hibernation before dividing. You should always wait for flowering plants to drop their blooms before dividing. If your bulbs are gladiolus, dahlias, or similar, it is a common gardening practice to dig up and divide the plant. Then you can store the bulbs in a cool, dry location until planting in the spring. This method of protecting your plants not only protects them from weather elements, but from hungry animals that could conceivably obliterate your entire stock of bulbs in a year.
For plants that bloom early, be sure to care for them in late autumn as well. No matter what time you divide these plants, the technique is the same. Cut the foliage down to only a few inches before dividing, unless the foliage is evergreen. If it is an evergreen, leave all healthy foliage but remove any dead leaves or stalks. If your plants root system is a bulb, carefully divide the bulbs. Plant some of the bulbs in areas with less successful plants, and store the extra bulbs to replace any that might be eaten or succumb to the cold winter weather.
For clumping perennials, carefully trim the foliage to only a few inches. Then dig up the plant and cut it into several pieces with gardening shears. Each piece should have a good set of roots and some stalks as well. Do not make the mistake of cutting each plant into too many pieces. If you are unsure of the plant, or do not already practice regular division, plan on cutting each plant into only one or two pieces. As you get more practiced with this skill, you will begin to know which plants can be divided further.
Plant these divisions of the original plant as desired. For plants that no longer fit into your garden, bring the divisions inside and plant them in pots for the winter. Later you will be able to replace any dying plants with these indoor plants.
Devote one weekend a year to carefully dividing and caring for your bulbs and clumping perennials. A regularly scheduled maintenance will help your plants and allow you to avoid any extensive crowding problems. Keep in mind that not every plant must be divided every year. Take the time to store excess bulbs and plants. You never know when you might need them, and giving away excess bulbs in the spring is an easy way to promote your hobby to others.