Even in the smallest garden, April is the month when the growing season really begins to gather pace. Flower beds start to fill out with the bushy new shoots of herbaceous plants and leaves once again begin cover the branches of trees. With such fecundity its easy to let things slip out of control in the garden and before you know it you will realize there are a number of jobs you should have done and now it’s too late. So before you venture outside take a quick reminder from this list of vital jobs to be done in the flower garden during April.
April is the time to plant herbaceous borders. Infill any gaps in the flower border with perennials. Plant in groups of three or five for maximum effect. The emerging shoots of some perennials such as lupins and delphiniums are particularly at risk from slugs and snails so protect them with an organic barrier such as garlic or coffee granules. Tie the emerging shoots to plant supports. April is the time to plant out the sweet pea seedlings you sowed back in February. Also, it’s the time to sow hardy annual flowers such as sunflowers directly into beds where you want them. Fork a good helping of compost into the soil to help it cater for the new growth and annual flowers you have added to the border. April is also a good month to plant a lavender hedge. Choose a suitable variety such as the hardy Munstead dwarf.
If you grow oriental poppies in your flower garden now is the time to support them with canes to prevent them from flopping over. Also, secure the new shoots of clematis to supports, taking care not to snap the delicate stems. Start to spray roses that are vulnerable to diseases such as blackspot, mildew or rust. Plant out groups of gladioli bulbs to a depth of around 10cm, making sure the place you situate them is not too wet.
Towards the end of the month prune back the stems of early flowering clematis such as Montana to ensure it doesn’t put on too much vigorous growth. Any box topiary you have will have started to put on new growth at this time, so give it a trim to keep it in shape. Any container grown shrubs and roses you have bought can also be planted out towards the end of the month. Finally, at the end of the month, fill garden planters with summer bedding displays but keep in the shelter of the greenhouse until a risk of frost is well past.
Jo Poultney is a RHS qualified gardener who has recently set up a business selling garden planters and garden related gifts via a website.