Despite the curious weather that we have seen so far this year, by May we can assume that the risk of a hard frost has passed and with longer, warmer days everything should be growing.
Of course warmer weather means that the weeds will start growing quickly, so make sure that you keep on top of the weeding early in the season before annual and ephemeral weeds set seeds and perennial weeds get established. Warmer weather also brings out the pests and Lily beetles and aphids are both problems at this time of year. Watch plants carefully to make sure that if pests are starting to infest that you catch them early. Observation is at the heart of an integrated pest management system.
More positively, you can start thinking about extra summer colour now, as well as summer bedding in borders, summer containers around doors and sitting areas brighten up the garden at a very reasonable price. The colours of summer bedding are great, but as well as colour, don’t forget scent and even edible options. A hanging basket of tumbling tomatoes looks good, gives a hefty crop and is a conversation piece. Another eye-catching option, that will also give heady scent, is to create a wigwam of sweet peas in a large pot. If you cut the flowers regularly it will help prolong flowering giving you benefits both indoors and out.
May is the peak month for Rhododendron flowers, so dead-head them at the end of the month to create space for new shoots.
For high and late summer colour, dahlias and Cannas are popular and reliable performers. Neither of these plants are frost hardy, so make sure that you wait until all risk of frost has passed before putting them out. If you have facilities like a greenhouse, then bringing dahlias on in a greenhouse will mean that the plants are much bigger by the time you plant them out and flowering will start earlier.
In the vegetable garden you should be earthing up potatoes and planting out the tender summer fruiting crops such as courgettes, squashes and tomatoes. If you’re lucky enough to have an asparagus bed then you should be reaping the rewards of your foresight right now.
You’ll probably be into regular grass cutting by now and a high nitrogen feed will help the sward to thicken up. If you have problems with moss and want to reduce the weed population, then it is worth using a complete “weed and feed” mixture. Following a treatment with scarification will get rid of thatch and dead moss and get air to the grass roots to help the grass plants grow more strongly.