What to do in the garden in June
June is the month to enjoy the garden at its freshest and keep it growing strongly. The key jobs are watering wisely, deadheading to keep flowers coming, tying in climbers and tall perennials, pruning shrubs that have just finished flowering, and sowing biennials for next spring. A little time each evening now pays back all summer long.
Water deeply, not daily
June can bring long dry spells, especially in the south and east. The most effective way to water is a thorough soak once or twice a week, aimed at the base of the plant, rather than a light sprinkle every evening. Deep watering encourages roots to follow the moisture down, which makes plants far more resilient when it gets hot. Focus on what really needs it: anything planted this year, containers, and vegetables that are flowering or fruiting. Established shrubs and perennials usually look after themselves.
Water first thing in the morning or in the evening, when less is lost to evaporation, and use water from a butt wherever you can. A mulch of garden compost or well-rotted organic matter over damp soil will help it stay moist for longer.
Deadhead for more flowers
Regular deadheading is one of the most satisfying jobs of the month. Snipping off faded flowers on roses, sweet peas, cosmos, osteospermums and bedding stops the plant putting its energy into seed and encourages it to keep flowering. Sweet peas in particular need picking every few days, and the more you cut, the more you get. Leave the flowers on anything you are growing for seedheads or hips later in the year.
Cut back early perennials for a second flush
Some early summer perennials respond brilliantly to a haircut once their first flush fades. Hardy geraniums, oriental poppies, lupins and catmint (Nepeta) can be cut back hard, almost to the ground in the case of geraniums and poppies. Give them a good watering and within a few weeks you will have fresh, tidy foliage, and with many geraniums and catmint a second round of flowers too. If you love catmint, my post on planting geum, salvia and nepeta together has more on making the most of it.
Prune early summer shrubs
Shrubs that flower on growth made the previous year, such as mock orange (Philadelphus), Weigela, Deutzia and Kolkwitzia, should be pruned straight after flowering. Cut out around a third of the oldest, thickest stems at or near the base. This encourages new shoots that will carry next year's flowers and keeps the shrub open and healthy rather than tall and woody. If Clematis montana needs tidying and you did not get round to it in May, do it now as soon as it has finished flowering.
Tie in and support
Everything is growing fast, so go round with soft twine every week or so. Tie in new shoots of climbing roses as close to horizontal as you can, which encourages flowering shoots all along the stem. Guide clematis and sweet peas up their supports, and check that tall perennials are held securely before summer storms arrive.
Sow biennials and take cuttings
June is a perfect time to sow foxgloves, honesty, sweet williams and wallflowers, either in modules or in a spare patch of soil. They will grow on through summer and can be planted where you want them to flower in early autumn. It is also a good month to take softwood cuttings from plants such as penstemons, salvias, fuchsias and lavender. Choose a non-flowering shoot, cut just below a leaf joint, remove the lower leaves and push it into a pot of gritty, peat-free compost. Cover with a clear bag and keep it somewhere bright but out of direct sun.
June checklist
Water new plants, containers and crops deeply, once or twice a week.
Deadhead roses, sweet peas and bedding to keep them flowering.
Cut back hardy geraniums, poppies and catmint after their first flush.
Prune philadelphus, weigela and deutzia once they finish flowering.
Tie in climbers and check supports on tall perennials.
Sow foxgloves, wallflowers and other biennials.
Take softwood cuttings of salvias, penstemons and lavender.
Pinch out side shoots on cordon tomatoes and feed weekly once flowers appear.
In the vegetable and fruit garden
Pinch out the side shoots that grow between the main stem and the leaves on cordon tomatoes, and start a weekly high-potash feed once the first truss of flowers has set. Keep sowing salads, beetroot and carrots in short rows for a steady harvest. Fruit trees often shed some of their young fruit naturally in what is known as the June drop. Once this has happened, thin apples and pears further if clusters are heavy, leaving one or two fruits per cluster for better-sized fruit.
Lawns and wildlife
In dry weather, raise the height of the mower blades and cut less often. A slightly longer lawn stays greener and copes with drought far better, and if it does turn brown it will recover quickly once rain returns. Leaving a patch or two to grow longer gives you flowers for pollinators and cover for insects. Top up ponds and bird baths with rainwater where you can.
If you missed anything last month, the May jobs are still worth a look, and the July jobs carry on from here.
Quick answers
When should I prune philadelphus and weigela?
Straight after they finish flowering, usually in June or early July. Remove about a third of the oldest stems at the base so new growth can carry next year's flowers.
How often should I water my garden in June?
Established plants rarely need watering. New plants, pots and vegetables benefit from a deep soak once or twice a week in dry weather, with containers checked daily in hot spells.
Can I still sow foxgloves in June?
Yes, June is an ideal time. Sow them thinly on the surface of the compost as they need light to germinate, and plant the young plants out in early autumn to flower next year.
