Head Gardeners’ tips
September 2023

September is a wonderful time to reflect on the year so far in our gardens. In Horatio’s Garden South West, we are looking at our borders and considering the tweaks and changes to make. How have our garden plants performed this year? Which plants have become too bullish and dominating? Where can we add in more seasonal colour and interest?

Once we have reflected upon our gardens and considered changes to the planting within it, now is the ideal time to take action. September is also the perfect time to look at ways to bring new additions to the borders. We can consider adding these new plants in a number of ways;

• Lifting and dividing existing herbaceous perennials – As we go into autumn the soil has warmed up over the year which means that any new plants will more readily be able to establish and put on root growth before the cold of winter arrives. Over the last few years with the drier hot summers I would usually wait until October, however our wet unsettled summer this year means the conditions are ideal. When lifting and dividing plants it is advisable to remove some of the vegetative growth first. This will enable the disturbed roots to support a smaller area of vegetation whilst repairing and settling into the soil. Any plants that you decide not to replant can be potted up and shared with friends. Remember to keep the newly replanted specimens well-watered as they establish.

• Saving seeds from existing plants – Choose a dry day to collect seeds from plants; you will know when it is ripe as it will come away from the plant easily. The seed can be sown now or stored for the future but do ensure it’s fully dry before storing long term. Keep collected seed in a cool dry environment. Some seeds we are collecting now – Digitalis lutea and ferruginea.

• Taking cuttings – Now is the ideal time to be taking semi-ripe cuttings. This will give you an insurance policy in case some of your less hardy specimens don’t make it through the winter. Plants to consider taking cuttings from now include Salvias, Penstemon and Pelargoniums.

• Spring bulbs – These are now available to order and purchase. If you have particular varieties and favourites in mind, best to get in early to ensure you don’t miss out! We will be holding off from planting our bulbs until later in autumn, partly to allow for borders to die back and partly as we make some changes to the current planting schemes. Tulips can be planted as late as early December.

September is also a time for celebration. A time to share and enjoy our garden spaces and any produce we have grown. Tomatoes, cucumbers, courgettes, chillies and peppers are all still producing and should be picked when ripe to encourage other fruit to ripen. Remove the lower leaves from tomatoes plants to expose the tomatoes to sunlight and encourage ripening.

Keep cutting and deadheading your annual flowers. Dahlias, Cosmos, Tithonia and Zinnia will give you colour until the first frosts. Enjoy bouquets of your flowers around your home.

We can have some gloriously sunny weather still in September, so make sure you take the time to enjoy these moments and share all your hard work with others.