How to keep your garden blooming all summer long

Irish Times

11 hours ago

Glittering with beauty and laden with promise, the garden in early June is like a table sumptuously set for a glamorous dinner party, repaying all the hours of hard work behind the scenes. If you, for example, pruned and fed your roses to textbook perfection at the beginning of the year, the reward right now is their bounteous, beautiful, scented blooms.
Likewise, if you forced yourself reluctantly outdoors to plant seed potatoes back in the damp, icy months of spring, then these plants should already be forming tasty tubers deep beneath the soil. Similarly, if you got young sweet pea plants into the ground back in late March to early April, then they'll be readying themselves to throw out their first delicate, perfumed blooms.
It's a similar story for all those tender plants and baby seedlings that we gardeners have coddled through frosty nights and studiously protected from slug damage. Ditto for the summer-flowering bulbs and hardy biennials planted in the muck and mist of last autumn, including alliums, Dutch irises, sweet William, and Canterbury bells now coming into bloom. And ditto for all those summer-flowering herbaceous perennials laboriously lifted and divided what feels like so many moons ago, now starting to lustily flower their hearts out.
Summer-flowering bulbs and hardy biennials planted last autumn are readying themselves to throw out their first delicate, perfumed blooms, including alliums (pictured), Dutch irises and sweet William. Photograph: Mint Images/Getty
What comes next, however, is the challenge of keeping this very beautiful show on the road. Try to make it a routine, for example, to deadhead faded flowers daily, a simple task that prevents flowering plants from switching their energies to seed production rather than blooming. Likewise, don't presume that rainy weather will be enough to keep summer pots and container-grown plants sufficiently irrigated, especially as their leafy canopy increases over the coming weeks, preventing enough water from reaching their thirsty root systems. Instead, check them every day, sticking your index finger at least 5cm into the compost to accurately gauge if it's sufficiently damp.
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Check the compost's weight too. If it feels light, then there's a risk that the compost is only surface-damp – bad news for plants' probing root systems. If in doubt, fill a wheelbarrow with water, plunge the pot up to its waist, and leave to soak for several hours. This same technique is also a great way to deep-feed plants with a liquid solution of seaweed, a brilliant natural health tonic that helps to boost plant vigour, floriferousness and productivity. The latter is also very effective applied as a foliar feed every 10-14 days throughout the summer, using a watering can or spray.
Ireland's variable summer weather poses challenges. It's at this time of year, for example, that many fast-growing herbaceous plants become vulnerable to wind damage
The same goes for homemade 'nettle tea' and 'comfrey tea', both of which are rich in beneficial plant nutrients. Just bung plenty of their soft, young leaves into a lidded container, cover with water and leave to stew for several weeks. The resulting foul-smelling liquid will need to be strained and diluted to the colour of weak tea before being applied as a foliar feed, making sure to wear protective clothing to prevent yourself from smelling like a medieval cesspit if you accidentally get it on your skin. All these liquid feeds can also be used to encourage hungry, early-summer flower perennials such as oriental poppy, lupin, geranium, geum, delphinium and astrantia to produce a second flush of flowers. Just cut the plants back hard once they go over, before generously watering and then liquid feeding them.
Ireland's variable summer weather also poses challenges. It's at this time of year, for example, that many fast-growing herbaceous plants become vulnerable to wind damage. Likely victims include the tall, brittle flowers of delphiniums and lupins, which can snap in a summer gale if not given sufficient support in the shape of cunningly concealed stakes or purpose-made plant hoops.
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Fast-growing climbers such as clematis, honeysuckle, morning glory and sweet pea can also quickly collapse under their own weight, unless carefully trained up sturdy vertical supports. The same goes for climbing French beans, sugar snap and mangetout peas. Similarly, young courgette plants, not yet fully used to the rigours of an Irish summer, can get tattered and torn unless given a temporary blanket of fleece and some twiggy pea sticks to steady their fleshy, hollow stems and provide a gentle scaffold for their foliage.
With plants growing in glasshouses and polytunnels, it's a different story. Here, the greatest risk of harm comes from extremes of temperature and irregular watering. Resist, for example, the urge to keep all doors and vents firmly closed on cooler days. This will only result in overly hot growing conditions and poor ventilation, causing plant stress and even death. When you water, do it generously and thoroughly, the aim being to properly soak the roots, but not so regularly and copiously that you constantly create the kind of very humid, muggy conditions that greatly increase the chances of certain pests and diseases. For the same reason, aim to water only the soil rather than the plants themselves.
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Both outdoors and under cover, keep a beady eye out for any early signs of slug or snail damage and take suitable precautions to prevent it from recurring. Hand-collecting slugs and snails from around vulnerable plants at night by torchlight is a useful way to minimise the damage. Also bear in mind that rank, weedy growth and garden 'dumps' of discarded pots and half-used bags of compost are among their favourite hiding places.
Think ahead to the dog days of summer. Consider making some late sowings of fast-growing vegetables such as lettuce, annual spinach and oriental salad leaves to fill the growing space left behind by an early crop of potatoes
Speaking of which, early June is an excellent time to hoe and hand-weed beds, borders and paths before weeds get badly out of control and start to self-seed, creating further problems. But try to do so cautiously to avoid accidentally uprooting any emerging, desirable, self-seeded seedlings that you might wish to keep.
It's a good time at the moment to sow sweet William, pictured above with daisies below them. Photograph: Getty
Finally, think ahead to the dog days of summer. Consider making some late sowings of fast-growing vegetables such as lettuce, annual spinach and oriental salad leaves to fill the growing space left behind by an early crop of potatoes, for example, or sow purple sprouting broccoli for a delicious spring crop. Weigh up, too, any potential weak spots in container displays or flower borders and think of ways that these might be easily and effectively filled later in the season with a few judiciously placed pots of late-flowering varieties such as dahlia, nicotiana, salvia, rudbeckia, sedum and helenium. In this way, your summer garden is guaranteed to go out with a bang, rather than a whimper.
This week in the garden
Tender, heat-loving vegetables such as courgettes, French beans, sweetcorn, pumpkins, and squash can now be safely planted outdoors. Choose a warm, still day, making sure that plants are properly hardened off in advance. It's also a good idea to initially protect young plants with garden fleece.
Now's a good time to sow seed of hardy biennials such as wallflowers, Canterbury bells, sweet William and honesty. Recommended specialist suppliers include
seedaholic.com
and
mrmiddleton.com
Dates for your diary…
RHSI Bellefield Open Weekend
Bellefield House, Shinrone, Co Offaly. Today and tomorrow. With guided tours by head gardener Paul Smyth at 12pm and 2pm each day, plus plant sales.
rhsi.ie
Buds & Blossom Garden Show
Spink, Community Grounds, Abbeyleix, Co Laois. Tomorrow, Sunday, June 8th (12pm-6pm). Guest speakers John Jones, Colin Jones and Tom Coward, plus specialist plant sales by many of Ireland best small independent nurseries.
laoisgardenfestival.com
Rathmines Open Gardens 2025
Tomorrow, June 8th (2pm-6pm). In association with The Rathmines Initiative, with several private gardens opening their doors to the public in aid of charity, along with Trinity Botanic Garden. See
therathminesinitiative.com
or contact Michael Kelly on 087 669 7722 for details.