Which species are best to divide in the fall?
In autumn, we reproduce perennials that bloom in spring by dividing them. These are, among others: periwinkle, phlox, brunner, crested bug, goose, hearts, saxifrage, cocklebur, lily of the valley, cranberry and geranium. We start digging up the plants when they have already bloomed. At the same time, it is early enough for them to take root well before winter and produce buds, from which they will sprout new shoots in the spring. Spring-flowering perennials are frost-resistant, so they usually do not cause much trouble, even if planted a bit too late.
The autumn division is aimed not only at acquiring new plants, but also at rejuvenating the old ones - too little or too dense. Too high a density can lead to lower flowering and exposes plants to fungal diseases. If the plants are not blooming as profusely as they used to be, or are simply too large for the space they occupy, dig them up and divide them.
How do we divide perennials?
This operation is best performed on a cloudy day. The day before splitting, the plants should be well watered. Using a fork or a spade, we lift the clump, lifting the entire root ball up and pulling it out of the soil. Then shake off the clump well, remove any dead or rotten roots and divide the lump into several parts. It is best to do it by hand, then the roots will be broken in places where they offer the least resistance and we will get the highest number of new cuttings.
Small plants with fibrous roots, such as phloxes, geese or lily of the valley, can be gently torn apart after digging up. If the clumps are relatively small, you can often do this with your hands.
It is even easier to divide the species that make up the stolons, such as the saxifrage, the common oakwort or the common periwinkle. Plants root at the nodes, so it is enough to use a spatula to pry the rooted plant and cut it off from the mother plant.
Species that form a strong, more woody root system such as daylilies and bush peonies may require more work. After digging up, the root ball often requires the woody roots to be cut into smaller ones. Using sharp tools, cut the woody roots vertically to obtain cuttings. Each of them must have several roots and at least one bud.
Advantages of autumn dividing and planting perennials
Autumn is the best time to reproduce and rejuvenate perennials. The soil, warmed up in summer, has a temperature that is favorable for plants to take up in a new place for a long time. Heavy rainfall and high air temperatures allow for strong rooting of cuttings.
Favorable weather conditions favoring the rooting of plants are not the only advantage of autumn planting. Perennials planted in September or October significantly increase their resistance to disease and pest attacks. With the onset of spring, they will absorb moisture from the soil as much as possible, which will allow them to develop better, bloom and be stronger.
In September or October, we can plant popular autumn perennials, e.g. asters, heathers, Japanese marshmallow, chrysanthemums, tawułki or cranberries.
