It’s Time For Summer Containers!
When I was asked by a local nursery to do a series of container planting demonstrations, I leapt at the chance. Planting in containers is one of the most enjoyable and rewarding activities one can do in the garden: in many cases, the impact is instant (not so much if you’re working with bulbs in autumn) and the results only get better with time.
Because container plantings are generally regarded as temporary, it’s possible to mix and match plants that would be impossible to combine permanently in garden beds, affording an infinite number of exciting possibilities. Annuals, biennials, perennials, shrubs and even trees can be grouped together in containers to create anything from subtle, tonal stories to showstopping, eye-popping statements. Think of container gardening as an art somewhere between flower arranging and full-on garden design: less transient than the former and not as fixed or considered as the latter. Containers are not just suitable for hot, sunny patios, but for shady spots and wild gardens too. And if you don’t like them where they are, they can always be moved elsewhere or changed for something different.
Now, in late spring, gardeners across the country are preparing to plant pots, tubs, troughs and hanging baskets for the summer season. Here are the ‘recipes’ for four containers I put together in collaboration with Young’s Nurseries for our local spring fayre. There’s no need to adhere religiously to any of them – you can change the container and plants to please yourself and suit your garden. If you can’t find exactly the same plants, garden centre staff should be able to suggest good alternatives.
Before you begin creating the perfect pot, here are a few container planting tips and tricks to set you off in the right direction. If you’re a seasoned pro, you can skip straight down to my four container projects.
Container Gardening Essentials
– Choose the right container – taking time to select the right container is important. Generally, bigger is better to create a more stable growing environment, to give plants space to develop and to reduce the subsequent maintenance required. Consider the best material for you, both aesthetically and functionally. Terracotta pots are timeless and age gracefully but they’re porous so they need watering more frequently and can shatter in frosty weather. Metal can look smart but heats up and cools down quickly giving the delicate roots inside little protection. Wood is natural and characterful but requires regular maintenance. Plastic has its place, but we all know the environmental downsides. Avoid pots with inward-facing lips or those that are narrower at the top than lower down if you want to remove plants from them later on without breaking them to do so.
– Keep them clean – clean containers between each use. As a minimum, scrub them inside and out with a stiff brush to remove any old compost and tenacious pests before refilling. If it’s feasible, wash your container in hot soapy water to kill bacteria, algae and fungal spores that might impede plant growth later.
– Think about drainage – whether you’re planning to grow sun-loving succulents or moisture-loving hostas, you will still need a way for excess water to drain away from your container. Trapped water will stagnate and go sour, suffocating a plant’s roots. To avoid problems, make sure your container has plenty of holes in the base and don’t block them when filling with compost. Crocks are largely pointless unless you are trying to fill a large void quickly and cheaply. A layer of horticultural grit or moss inside the base of the pot will allow water to drain out and keep compost in. Use pot feet only if you live in a very wet area or your container is prone to becoming waterlogged.
– Compost – we should all be using peat-free composts by now. A soil-based compost gives a container extra weight which is ideal for windy situations and tends to aid moisture retention. However, a heavy pot filled with wet, soil-based compost can be extremely heavy and difficult to move. A compost made from natural matter such as bark, leaves, bracken or wool will be lighter but may dry out more quickly. Never fill containers with garden soil as the microorganisms and soil fauna that are so beneficial in open ground can play havoc in a restricted space. Equally, never re-use old compost as it will have lost all its nutritional value, structure and is probably harbouring pests and diseases.
– Planting – plants can be packed into containers much more closely than they can in the garden, mainly because they are usually there temporarily. Ideally, you don’t want to see the surface of the compost after a week or so. Think about what will be your focal point – perhaps this might be a vertical accent like a foxglove or a standard rose, or it might be a particularly bold, architectural form such as a cordyline. If you want to cover the sides of the container, you’ll need a plant that trails or flops. Then you’ll need fillers – foliage or flowering plants – to occupy the bulk of the container. There are no rules, but it does help to play about with your chosen plants before committing them to the container. And if you want your display to last, you should find out how long the plants will bloom and make sure you have sufficient interest to come later.
– Feeding – compost bought in sacks typically contains enough nutrients to keep plants healthy for 4-6 weeks. That’s not very long in the scheme of things. Add slow-release fertiliser granules to the compost at the time of planting and within 6-8 weeks begin feeding regularly with a liquid fertiliser.
– Watering – no container is going to flourish without regular watering ….. and don’t expect the rain to do it for you. Densely-planted pots filled with foliage shrug off water so they’ll need regular refreshing with a hose or watering can. On a hot, exposed patio, expect to water once or twice a day in summer. In a cool, shady spot you may get away with watering a couple of times each week. Even in the winter, pots may need watering if the weather is dry. Consider what you’ll do if you’re planning a holiday while your container is in its prime.
– Pests – closely-planted pots can be a haven for pests and diseases both above and below soil level, so remain vigilant and deal with problems promptly. Wherever possible use physical means – i.e removing the pests by hand – or biological controls such as nematodes. Avoid using chemicals. If you must, use them only as a last resort and at a time that won’t harm precious pollinators. Siting your container somewhere that’s well ventilated will help to stop fungal diseases, moulds and mildews from taking hold.
Recipe 1 – A bee-friendly bowl
This bright and breezy bowl arrangement was inspired by my recent research into pollinator-friendly plants. Some pots can look very neat and formal and I wanted a container that felt organic enough to take pride of place in a wild garden. I selected this particular bowl because of its wonderful irregular glaze – it looks a bit like the surface of the moon. I chose plants with lots of different flower shapes to appeal to as many different pollinators as possible, including foxgloves, thistles, sweet rocket, Swan River daisies and rock roses. Carder bees use the tiny fibres on the surface of felty leaves like verbascum to furnish their nests – something I hadn’t appreciated until I did my research.
Starting from the middle, I planted the tallest plant (the foxglove) just slightly off-centre and then began adding the other plants around it, reducing in height towards the edges of the bowl. In time, the Mount Atlas daisies, osteospermum and rock roses will tuble over the sides of the pot and fill the planting out. It’s worth noting than any container planting scheme takes a while to settle down and will not look its best immediately. Within 2-3 days any stems and flowers that are facing the wrong way should sort themselves out and after a week the plants will start to gel and appear to have grown together naturally. Give it a month or so for the display to bulk up properly. Deadhead flowering plants regularly to keep the blooms coming.
Digitalis purpurea ‘Alba’ (biennial) – foxglove Cirsium rivulare ‘Atropurpureum’ (perennial) – plume thistleTellima grandiflora (perennial) – fringe cupsHesperis matronalis (biennial) – sweet rocketVerbascum ‘Pink Petticoats’ (biennial or short-lived perennial) – mulleinOsteospermum ‘Voltage Yellow’ (short-lived perennial) – Swan River daisyAnacyclus ‘Silver Kisses’ (perennial) – Mount Atlas daisyHelianthemum ‘Elfenbeinglanz’ (sub-shrub) – rock rose
Top Tip – this planting combination would benefit from some gentle tweaking as the summer progresses. Although many of the types chosen can be perennial, they mostly flower in early summer. I would weave in some Verbena bonariensis and perhaps cosmos, rudbeckia or echinacea to provide a source of food for bees and butterflies later in the summer.
Recipe 2 – Fire and brimstone
My colour preferences for any type of planting lie at the hot end of the colour spectrum – reds and oranges combined with smouldering purples. I intended for this container to have a strong presence and to suit a contemporary garden. A high proportion of perennials means that only the annual petunias (x Petchoa) would need to be replaced, perhaps with some strong red wallflowers or a tulip such as ‘Rococo’ or ‘Hermitage’. I deliberately didn’t include trailing plants so as not to hide the geometric pattern that’s repeated around the sides of this tall, fibre pot. In time, the petunias and osteospermums will spill over the edges in any case.
Physocarpus opulifolius ‘Diabolo’ (shrub) – ninebarkHeuchera ‘Apricot’ (perennial) – coral bellsHeuchera ‘Chocolate Ruffles’ (perennial) – coral bellsOsteospermum ‘Astra Orange Sunrise’ (short-lived perennial) – Swan River daisyx Petchoa ‘BeautiCal Cinammon’ (annual) petunia hybrid
Top Tip – you could take this pot to the next level of exoticism by replacing the ninebark with a dark-leaved canna such as ‘Australia’ or ‘Tropicanna Black’. Alternatively, a multi-stemmed cluster of succulent black rose, Aeonium ‘Zwartkop’, would create quite a talking point. (Both the canna and the black rose would require winter protection.)
Recipe 3 – A glazed bowl for kitchen grazing
The idea behind this pretty bowl was to provide a source of herbs and edible flowers for a small garden. It could be placed on the ground or better still on a sturdy garden table for easy picking. I added extra grit to the compost mix to create good drainage for herbs like thyme and oregano that flourish in dry, Mediterranean regions. Violas and lavender produce edible flowers that can be used for flavouring and garnishes – they are both wonderfully scented too. Verbena and mullein were chosen more for their colour than their taste, but they’d do no harm if eaten. A topping of white alpine gravel sets off the flowers but has a practical function too – it reflects light back onto these sun-loving plants.
Lavandula stoechas (shrub) – French lavenderOriganum vulgare (perennial) – wild marjoramVerbascum ‘Lavender Lass’ (biennial) – mulleinViola ‘Rebecca’ (perennial often planted as an annual) – violaThymus ‘Silver Posie’ (perennial) – thymeThymus ‘Common Compact’ (perennial) – thymeVerbena ‘Firehouse Grape’ (generally treated as an annual) – verbena
Top Tip: Chose herbs that you are going to use and pick them frequently to encourage neat, bushy growth. Avoid mint which will dominate the whole pot within a few months, but try prostrate rosemary, sage or camomile if you enjoy their distinctive flavours. Keep the pot somewhere sunny and protect it from the worst of the winter cold and wet to help the herbs come through for another year.
Recipe 4 – Glowing foliage for cool, shady spot
Few gardens, particularly urban ones, bask in sunshine from dawn until dusk. Many of us have to contend with side returns, courtyards and backyards that enjoy only partial sun with corners that are permanently shaded. I see these as opportunities rather than problems – places to grow some truly wonderful plants that enjoy lower light levels and cool conditions. And before you jump to the conclusion that I’m going to suggest ferns, wonderful as they are, there are plenty of other options. This pot was created for a fictional, sheltered corner with no direct sunlight where I imagined it would cast a soft, golden glow. Foliage plays the lead role with flowers in support, offering colour for most of the year. The acer, iris and sedge lend a quietly oriental feel to the finished arrangement.
Acer ‘Orange Dream’ (shrub or small tree) – Japanese mapleIris sibirica ‘Not Quite White’ – Siberian irisTellima grandiflora (perennial) – fringe cupsCarex oshimensis ‘Eversheen’ (perennial) – sedge grassLysimachia nummularia ‘Goldilocks’ (perennial often planted as an annual) – golden creeping Jennyx Heucherella ‘Eye Spy’ (perennial) – foamy bells
Top Tip: If you had a wall or fence to place this pot against, the acer could be replaced with a gold-variegated ivy or even a clematis to climb up and provide some colour higher up. The acer will do best if watered using rain water, so perhaps locate this pot close to a water butt to make life easier.
This article originally appeared on The Frustrated Gardener