This Month in Your Garden - May

"I love spring anywhere, but if I could choose I would always greet it in a garden."

Ruth Stout, Author, Gardener

Many of us have been out there at the end of April tending to the tender plants as the frost bites with the cold weather front. Dahlias are tender and growing plants are best kept in the warm until the frosts pass before planting out in early June to create their dazzling displays.

If you haven’t the room or the time to grow your own bedding plants you’ll probably be eager to pop into the garden centre to pick up your half-hardy border plants. But the summer bedding, in most areas, will be best planted out at the end of the month, with the exception of areas that are still cold enough to cause damage to the plants.

Conversely, a lot of areas have had a dry April and some watering may be necessary. It’s best to water early and late in the day and ideally you’ll have a water butt collecting the water from a downpipe, or off the roof of a shed or greenhouse.  Biennial flowers such as pansies, Bellis and wallflowers can be sown now and up to July, to produce spring bedding for next year; and the same applies to winter bedding plants.

Faded flowers and early spring bedding can be removed to make space for your summer bedding and now is the time to divide herbaceous perennials and overcrowded bulbs such as daffodils after the foliage had died back. If you want to clear them before then you can make a temporary trench, lift the bulbs and ‘heel’ them in, covering with soil and leaving them until they are ready to lift and store. Alternatively, deadhead them (do the same for tulips) and let the leaves turn brown before lifting.  

• Give daffodils and other bulbs a feed if you’re leaving them to die back
• Divide Primula and primroses after flowering and divide hostas, to gain more plants 
• Cut back spring flowering perennials such as Aubretia and Alyssum to encourage more flowering 
• Lift forget-me-nots before they start seeding
• Take softwood cuttings of shrubs and herbs to propagate
• Plant out hardy annuals raised under glass
• Check supports for climbers and tall plants
• Treat roses for greenfly and apply organic slug pellets to protect plants and vegetables
• Tie in sweet peas and use plant rings as they grow
• Clean the greenhouse thoroughly if not already done and maintain a good airflow