Garden centres, supermarkets and DIY stores are blooming with trays of annuals such as petunias, marigolds and pelargoniums. However, those old-fashioned words of advice about holding off planting out until the arrival of June shouldn’t be ignored. So despite warmer temperatures worldwide, does the risk of late frost and biting winds still mean it’s too early for annual flowers and other tender plants this month?
George Weigel, expert at the National Garden Bureau explained: “Just because garden centres are selling tender plants doesn’t mean they should go in the ground.”
Although the weather may seem warm at times, late frost is still an issue for gardens in May.
Gardening expert Chris Bonnett, from Gardening Express said: “Frost can spell disaster for many tender varieties of summertime favourites from tomatoes and peppers, to popular bedding plants like fuchsias and pelargoniums.
“Even large established shrubs can suddenly be knocked back and suffer if they’ve already come into leaf.
“At least wait until the all-time-late frost-free time is approaching and check the 10-day forecast to be sure nothing is even close to a freeze before planting.”
Chris recommends using “those ingenious horticultural fleece bags that you just slip around a larger shrub that may be bursting into bloom or leaf”.
He added: “Simply zip them up, keeping them that little bit cosier on the colder nights.
“If you’re watching the budget, an old bed sheet secured with string wrapped around can be as effective.”
The gardening guru also advised mulching around the roots and tender stems of early emerging perennials and herbaceous plants such as peonies and dicentra, which could easily be ruined by a sharp frost.
Gardeners could also try setting an evening alert or alarm on their mobile phone as a reminder to check if they need to protect plants from frost by covering them up.
Chris added: “Make sure you actually go and do it.
“It’s no good closing the greenhouse door after we’ve had a frost, but it’s amazing how many people simply forget.
“Frost alert and weather apps are also available to download and will let you know if chilly weather is forecast.”