Tips and resources for farmers and gardeners
Dividing also can help prevent an existing bed from being taken over by one plant and it's fast, easy and inexpensive. If you have a new space that will require about 20 plants to fill in, for instance, you might consider buying only five perennials and filling the rest of it with annuals until the perennials get large enough to divide.
If you divide plants later in the season, cut back the foliage to reduce heat stress and encourage new growth. Warm, windy days will cause the foliage to wilt, no matter how moist the soil. Work in the cool hours of the day if possible and try to avoid windy days. It's best to divide a few days after rain or watering so the root system is moist and doesn't fall apart.
Some plants are fibrous or have a loose crown and root system, making it easy to pull them apart. A flat spade, pitchfork or knife can be used to break clumps into halves or quarters, while trying to leave the crown sections of the plants fairly intact. It may be easier to remove the entire plant before dividing. Keeping the clumps fairly large reduces stress and aids in establishment. If you'll be moving a lot of plants or sizable ones, consider using a wheelbarrow half filled with compost to fill any holes left behind; the compost will provide renewed, fertile soil for both the old and new plants.
Place plants at their original depth in a hole at least as wide and deep as the root spread so the roots aren't tipped up or curled back against each other. After planting, mulch with a 1-2 inch layer of grass clippings or straw and water them generously. When new growth appears, plants are on their way to establishment and can be watered less frequently to encourage roots to grow deep into the soil.
Karma Larsen, communications associate, Nebraska Statewide Arboretum, (402) 472-7923, firstname.lastname@example.org
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