Fall is an ideal time to divide hardy geraniums – discover how easy it is to reinvigorate plants and get new ones for free in 3 easy steps

If you are disappointed by how your hardy geraniums are flowering, or the clumps are going bare in the middle, then it is time to divide and rejuvenate them. This easy task can solve problems with poor flowering, and you get new plants for free.

You can divide hardy geraniums in the fall or spring, and it is a maintenance job best done every few years. When working at the world-famous Hidcote Manor Garden in the Cotswolds, I was involved in dividing many clumps of hardy geraniums as part of a redevelopment of the planting beds in the Pillars garden room.

If you are growing hardy geraniums and don’t regularly divide your plants, you are missing out on the benefits on offer. Here is what I learned about dividing hardy geraniums over my years as a professional gardener, plus some extra tips from a botany expert to help you successfully divide your plants.

When to divide hardy geraniums

Dividing hardy geraniums can be done during two specific windows of the growing season. Whether you choose to do it in the fall or spring is up to you, but it is an important part of caring for the perennials and a recommended way to keep geraniums blooming at their best for longer.

Hardy geraniums spread over the years, developing into larger clumps. However, their rapid growth can cause clumps to become overcrowded, often resulting in the centre of the clumps appearing bare compared to the edges. This is unappealing to the eye and will likely attract unwanted attention in any flower beds.

This common issue can be countered by remembering to divide hardy geraniums every 3-5 years. It can revitalize hardy geraniums, control the size of clumps, and encourage the strongest blooms. Plus, it gives you new flowering perennials to add to your backyard ideas for free.

'The best time to divide hardy geraniums is in late fall, after they finish flowering but before severe frosts harden the soil,' claims Nastya Vasylchyshyna, resident botany expert at Plantum. Dividing hardy geraniums in fall – they do make ideal perennials to divide in September – gives the plants time to bed down roots in their new home before winter.

If you miss the window to divide hardy geraniums post-flowering, or prefer to add the job to your spring gardening checklist, then you can divide clumps before they start actively growing in early spring.

The truth is that you can divide hardy geraniums anytime from early spring to early summer, but the earlier you do the task, the better. Dividing in spring means less watering is required to get the new clumps established, plus you will definitely get blooms in their first year.

Nastya Vasylchyshyna

Nastya is a professional botany expert for the Plantum app that helps identify plants and plant diseases and provides care recommendations. Her specialization is plant morphology, phytopathology, and plant physiology.

How to divide hardy geraniums

Dividing hardy geraniums can be quickly and easily done with some common garden tools, including a sharp shovel, garden knife, or hori hori knife. Ensure any tools are clean and sharp before undertaking the task, which guarantees they make clean cuts through the rootball.

Dividing plants can be done both in the fall and the spring by following these simple steps:

1. Carefully dig the soil around the clump and gently pull the geranium out of the soil
2. Use your sharp tool to divide the clump into pieces, ensuring that each section has both roots and shoots
3. Replant the sections as soon as possible, with the crown at soil level, and thoroughly water to settle them into the soil

It is always best practice to plant the sections immediately after dividing hardy geraniums, but if it is not possible, you can store them for a short time, provided the roots don’t dry out.

'If you can't plant them right after dividing, put all the parts together and water the soil ball or wrap the roots in a wet towel to prevent them from drying out. If you need to keep them like this for 2–3 days or longer, regularly check to ensure the roots stay moist,' recommends Nastya.

'However, it's better to avoid such a delay, so I recommend dividing geranium clumps only when you can plant them immediately.'

Newly-divided hardy geraniums will benefit from a handful of bone meal added to the soil before replanting the divisions. You can get organic bone meal at Burpee; it is slow-release and rich in phosphorus to promote the development of strong roots.

You can divide many perennials and shrubs to revitalize older plants and get new ones for free to add to your garden. However, some plants don’t respond well to being divided. Before you head out to split anything in your yard, check that they don’t feature in this guide to plants you should never divide, or you could risk losing them forever.

The best tools for dividing hardy geraniums