May is probably the busiest month in the garden. Plants (and weeds) are growing quickly so we need to keep on top of weeding, tying in new growth, staking…as well as sowing and planting new things.
Every year, though, I warn that frosts, and very cold nights, are still likely until towards the end of this month. Most summer bedding plants, marigolds, lobelia, begonias, Dahlias, etc are quite unhappy if the temperature drops below around 7C, which it often does.
The same applies to many vegetable plants, including runner and French beans, courgettes, sweetcorn and outdoor tomatoes. These can all be ‘hardened off’ now, but be prepared to either move them back inside or cover with a frost protection fleece if a cold night is forecast.
Hanging baskets and patio containers can be planted up now for a wonderful summer display. As above, though, make sure these can be moved inside or covered with fleece should a cold night threaten.
There are so many plants to choose from now, but the first rule is to start off with a good compost. I like to use a decent multi-purpose and add some loam-based (John Innes) which helps with moisture and nutrient retention. Water retaining crystals are a modern day wonder for keeping hanging baskets and containers looking good, as is a slow release fertiliser.
The most effective containers are often the simplest. A single variety, or two or three complementary species in a larger containers, tends to look far more effective than a mix of types and colours.
We all have our favourites; I like Pelargoniums (Geraniums) – particularly the scented forms – as they need very little in the way of water. This makes up for my other passion of Dahlias which do!
The Dahlias are shooting rapidly now from both overwintered tubers and new ones potted earlier this year.These new shoots can be taken as softwood cuttings around 10cm long, which will root very readily and give you extra plants in only a few weeks.
There are so many forms of Dahlia, from neat pom-poms to huge cactus or water-lily types. They always remind me of the Horticultural Shows where, traditionally, the Dahlia men were arranging their blooms at one side of the hall, whilst the Chrysanthemum brigade were busy on the other side. Dare I say, similar at first glance – both offering a range of shapes, sizes, forms and colours. I never met anyone who would be showing both….
But I like to break with tradition so intend to build up my collection of Chrysanthemums this year. There are many that are garden hardy, but it is the ‘fancy’ ones that I am tempted with – the spiders, spoons and quills.Grown in large pots, these will come into their own as the days are pulling in, with the blooms lasting for weeks in a cool greenhouse or the conservatory.
• Manea School of Gardening (RHS Approved Centre) teaches RHS Courses at all levels. Applications now being taken for September 2015. Now open for plant sales on Saturdays.