Astilbes, those beautiful and reliable perennials, can greatly benefit from being divided every few years. This simple process not only helps to rejuvenate the plant but also allows you to increase your stock and create more astilbes to enjoy in your garden. So, let’s dive into the details of when and how to split astilbes.
The ideal time to divide astilbes is either in the autumn after they have finished flowering or in early spring before new growth emerges. Dividing them during these periods gives the plants ample time to establish their roots before facing the stress of extreme temperatures or harsh weather conditions.
Dividing astilbes in the autumn has its advantages. By this time, the blooms have faded, and the foliage begins to die back. This makes it easier to see where the clumps are and determine where to make your divisions. Additionally, the soil is still warm, which encourages root growth and allows the divisions to establish themselves before the arrival of winter.
On the other hand, dividing astilbes in early spring can also be successful. This is best done before the new growth starts to emerge, as it allows the divisions to establish their root systems before the energy is directed towards new foliage. Early spring divisions also have the advantage of being able to take advantage of the increased moisture levels in the soil as the weather transitions from winter to spring.
Now, let’s talk about the actual process of dividing astilbes. Start by carefully digging up the clump of astilbe you wish to divide. Gently lift the plant out of the ground, being mindful not to damage the roots or crown. Once you have the clump out of the ground, use a sharp, clean knife or garden spade to divide it into smaller sections.
Each division should have a healthy portion of the crown, which is the central part of the plant where the leaves emerge. Aim to have at least three to five shoots or buds in each division, as this ensures that each new plant will have enough growth potential to establish itself successfully.
After dividing the clump, it’s a good idea to pot up the divisions before planting them back into the ground. This allows you to provide them with optimal growing conditions and ensures that they have a chance to establish their roots and grow stronger before being exposed to the elements. Use a well-draining potting mix and water the divisions thoroughly after potting them up.
Once the divisions are potted up, you can either keep them in a sheltered location or in a greenhouse until they have developed a strong root system. This will typically take a few weeks to a couple of months, depending on the specific conditions and care provided. Once the divisions have established themselves and are showing signs of healthy growth, you can plant them back into the garden.
When planting the divisions in the ground, choose a location that receives partial shade to full shade, as astilbes prefer these conditions. Prepare the soil by adding organic matter, such as compost, to improve its fertility and drainage. Dig a hole slightly larger than the division’s root ball, place the division in the hole, and backfill with soil, gently firming it around the roots.
Water the newly planted divisions thoroughly and provide them with regular moisture during the establishment period. Mulching around the plants can help conserve moisture and suppress weed growth. As astilbes are relatively low-maintenance perennials, they will require minimal care once established, but regular watering during dry periods and occasional fertilization can enhance their growth and flowering.
Dividing astilbes can be done either in the autumn after flowering or in early spring before new growth emerges. Both times have their advantages, but it’s important to ensure that the divisions have enough time to establish their roots before facing extreme weather conditions. By following the steps outlined above, you can successfully divide astilbes and enjoy the benefits of increased stock and rejuvenated plants in your garden.
