Six easy tips for making your garden planters last all summer in Ireland

Irish Times

24-05-2025

Who doesn't, I ask you, love a properly sumptuous, decadently lush display of summer containers, with all its fleeting, peacock-ish beauty and promises of long, lazy, sunny days. Few things we do in the garden can so quickly pack a powerful visual punch, as well as an emotional one, reconnecting us with childhood memories of sun-kissed terracotta pots filled with scarlet geraniums, and trailing lipstick-pink petunias spilling out of hanging baskets.
Concocting and then caring for these limelight-hogging creations so that they stay the pace throughout the summer months is, however, an art akin to making the perfect baked Alaska. Get it wrong and you'll end up feeling downcast. But get it right and your summer pots will be the envy of all who see them.
1. Containers
Let's start with the containers themselves. The first rule here, for many good reasons, is the bigger, the better. Larger pots not only offer much more room for hungry, thirsty root systems (many summer bedding plants are notorious guzzlers in this regard), but they also provide much more of an opportunity to create a truly eye-catching display. Better again, they're also less likely to dry out or become waterlogged.
Zinc is non-porous as well as being versatile and beautiful. Photograph: iStock
Also choose carefully when it comes to the type of material. Both natural terracotta and wood, for example, have a timeless elegance but are porous, so be prepared to put in more hours of watering on warm, sunny days. That's not the case with zinc, which is non-porous as well as being both versatile and beautiful, especially if you can get your hands on some vintage planters (stockists include
deebrophy.com
).
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Plastic, on the other hand, runs the risk of looking cheap and cheerful. Yet it also has the great advantage of being both non-porous and lightweight (important if it's going to be on a balcony or roof garden, where every kilogramme counts), plus you can give containers a clever upgrade by painting them in the colour of your choice.
2. Shape
Shape is another consideration. Too shallow, for example, and containers are prone to drying out. Too tall, and they're vulnerable to blowing over. Too much of a mix and it looks restless.
3. Compost
Just like choosing good quality ingredients for a recipe, your growing medium of choice is also crucial. Don't, for example, be tempted to reuse old, spent compost from last year's containers, which won't be capable of sustaining strong healthy plant growth. Likewise, beware of cheap, coarse, poor-quality compost that offers little in the way of nutrients. Instead, try your best to source a good-quality multipurpose compost, ideally peat-free for environmental reasons (I like Klasmann's peat-free potting compost, which is available to order online from Cork-based
fruithillfarm.com
and Sligo-based
quickcrop.ie
). Then add a handful or two of a good quality, slow-release organic fertiliser into it before planting, making sure to incorporate this well to avoid scorching vulnerable root systems.
Peat-free compost. Photograph: Alamy/PA
4. Plants
As for your choice of plants – the most important ingredients of all – there are a couple of cardinal rules worth bearing in mind. Firstly, if going for a mixed display of different varieties, make sure they all enjoy similar growing conditions. There's not much point, for example, in planting dahlias (a hungry, thirsty, fast-growing, heat- and sun-loving genus of plants) alongside ferns, which typically prefer shade and cooler conditions. Likewise, don't try to kid yourself that a container filled with sun-loving, drought-tolerant bedding plants is going to thrive in a cool, shady corner. Far better to plant appropriately, choosing species that will naturally flourish in the conditions your garden or allotment can offer them.
'Less is more' is another good rule of thumb, especially when it comes to the number of different species or varieties of plant. Choose just one single variety of dahlia, nemesia, pelargonium, ornamental salvia or nicotiana, for example, and it's guaranteed to create a visually powerful, long-lasting display, as well as one whose simplicity makes it easier to tend.
5. Colours
The same goes for your chosen colour palette. Restrict it to three or two colours, or even just one, and you automatically up your chances of producing a memorably beautiful display. This could be a combination of scarlet dahlias and petunias, or a massed display of just one single variety of cosmos, calibrachoa, nemesia, diascia, begonia, bedding fuchsia, or pelargonium. What's key is to focus on long-flowering, floriferous, high-octane species like these that earn their keep by performing well over a long period of time.
A summer container filled with Nemesia 'Peach' beside containers filled with Coleus 'Campfire' and Aeonium 'Zwartkop'. Photograph: Richard Johnston
Don't overlook the all-important power of a few high-value foliage plants in knitting it all together. Coleus, for example, is available in a mouthwatering range of colours, as are varieties of heuchera and heucherella, while the castor oil plant, Ricinus communis, can be used to quickly make a tall, dramatic display of vividly colourful foliage. Other hardworking foliage plants for summer containers include the silver-leaved Helichrysum petiolare, and Plectranthus argentatus.
Bear in mind that contrasting forms and different growth habits also make for a more interesting display. Placing, for example, a trailing plant next to one with a strongly vertical habit is always going to be pleasing to the eye.
6. The essentials
Last but not least, don't forget the essentials, which are to keep your pots watered (but not sodden); to zealously protect them from slug damage; to faithfully deadhead; and to start liquid feeding them every fortnight from midsummer onwards, ideally using a good-quality liquid seaweed. The rest is in the lap of the gods.
This week in the garden
Grab the chance to hand-weed and hoe weeds away from paths and beds while they're still young and small and relatively easy to manage. Choose a dry, warm day to help ensure they'll quickly die off, rather than rerooting.
Sustained dry weather can cause plant stress due to lack of moisture in the soil, so protect newly planted trees and shrubs by watering generously and then spreading an organic mulch around the surface of the soil to lock in moisture and slow down evaporation. Grass clippings are ideal for this purpose.
Dates for your diary
May 29th-June 2nd:
Ireland's biggest and best-known gardening show, Bord Bia Bloom, returns to the Phoenix Park, Dublin, with 21 show gardens; 11 postcard gardens; a host of floristry and nursery displays, including one from Kells Bay Gardens, which recently exhibited at the RHS Chelsea Flower Show; a new Botanical Hub Demo area; an Ask the Expert Plant Clinic, presented by The Irish Garden magazine; an Ask the Expert Tree Clinic in association with Crann; a Garden Design Clinic in association with the GLDA; plus talks by well-known gardening experts including Adam Frost, Leonie Cornelius, Jimi Blake, Mary Keenan, Diarmuid Gavin, Fiann Ó Nualláin, and Bloom Judges Andrew Wilson, Mark Gregory, Karen Foley, Paul Maher and Feargus McGarvey.
bordbiabloom.com