How to plant your pots this summer so your flowers bloom all year

Now that most of us are dedicated plant parents and keen gardeners, it's important to learn how to plant them in pots correctly so that the flowers bloom all year.

On a balcony, or in awkward side returns or paved-over yards, containers become the closest thing we have to flower beds. I treat them much the same way I now treat my garden beds and expect no less from either: colour, interest and texture all year round. If anything, during winter 2021, the pots looked better than the shy perennials lurking round the edges of the lawn.

Get the planting right and you’ll come to be endlessly surprised by your pots, which get far less attention than the rest of the garden. These trusted, long-planted containers are my horticultural equivalent of old friends, the ones whose houses you can rock up to in a tracksuit, with a bag of Doritos and demand to watch Bake Off. No wonder I’ve hefted them around three different flats, and countless staircases, in the past five years.

If this sounds like you, read on to find out my top tips on planting your pots for optimal flower blooming.

Building foundations

Start by taking a good, hard look at your growing space. Neither of the balconies I’ve grown on were large, but each held a handful of different aspects: morning sun, afternoon sun, rain shadows (where overhead cover keeps things dry) and deep shade. All can be grown in, but it’s important to understand these limitations before you start buying plants.

Wind can also be a factor on roof gardens and higher balconies, and shouldn’t be dismissed – it’s drying, and can make mincemeat of more delicate plants that need shelter.

If, though, you’re working with a brick-walled nook, you’ll have higher temperatures than elsewhere on your plot. Be honest with yourself about how much sunshine your space actually gets. Part-shade means three to six hours of strong direct daylight in summer; full shade is anything else. If you’ve got a fully exposed space, that’s worth noting, too.

These conditions will help steer you towards the start of your plant palette. It can help to think of comparative situations in the wild: coastal and dry gardens can be a brilliant steer for exposed roof terraces, for instance (if this is you, I strongly recommend you look up Derek Jarman’s garden at Prospect Cottage, followed by Beth Chatto’s Gravel Garden).

By contrast, I delved deep into woodland planting when trying to work out what would thrive on my shady balcony.

To keep a container looking good all year, you’ll want a base of hard-working perennials. For faux-woodland conditions, my go-tos are ferns, heucheras, hellebores and, of course, the plectranthus.

But if you’re blessed with more sunshine, grasses, sedums and artemisia would work well, too. Look for something that will be in leaf for most of the year: flowering is a bonus, and a fun one, but by embracing the beauty of foliage you’ll enjoy your pot for longer.

Layering up

Alongside these larger plants, you’ll want something that sits level with the top of the pot or, better, tumbles over it – again, for most of the year. Small ivies, muehlenbeckia, soleirolia soleirolii (aka mind-your-own-business) and even ivy-leafed toadflax and herb robert do the job perfectly and have root systems that aren’t too obtrusive.

A mix of these two categories of plants would do the job fine, but additional excitement comes with seasonal perennials that lurk below the surface and turn up for a season or two.

I’m fond of hostas, persicarias such as ‘Red Dragon’ and ‘Purple Fantasy’ and Oxalis triangularis ‘Purpleleaf False Shamrock’ but have played around with angelica and lamium in the past, too. These are all shade-tolerant, but Erigeron karvinskianus ‘Lavender Lady’ fennel and scabious could be gorgeous in sunnier spots.

I also count bulbs in this category: a tiny fanfare in the darkest of days.

My more evergreen containers get treated to occasional visitors too: muscari, Ipheion uniflorum ‘Froyle Mill’, iris, fritillaria and dwarf narcissus – ‘Pheasant’s Eye’ is a current fave – which don’t overwhelm the balance of things. But if you’ve got less greenery going on over winter, go wild with tulips and daffs; nothing is more cheering on the less than sunny days.

Top dressing

Finally, annuals. If you have room or fancy the novelty of a new colour, sowing a few seeds – ideally for things that won’t totally take over, such as nasturtiums and violas – can brighten up your pots. As can popping in a few plug plants ordered from a catalogue. For sunnier spaces, overwintering pelargoniums can be brilliant sources of scent and interest.

How many of each plant depends on the size of your container, but keeping to your plant palette will create a greater sense of lushness. I stick to a handful of plants and repeat them across all of my containers, the effect being more cohesive in every corner of the garden. In a smaller space, that’s even more crucial.

As for suitable containers, I strongly urge you to get the biggest you can afford and/or accommodate, and ideally nothing smaller than 40cm in diameter – you can get perennial planting in these, but they’ll dehydrate more quickly.

In terms of maintenance, I really did mean it about the Doritos-Bake Off set: get the right plant palette and they’ll be quite happy with minimum effort. Deadhead and cut back any crispy bits, water thoroughly in dry spells and give a generous mulch in late autumn and again in spring; a thick layer of organic compost will do.

Your biggest nemesis will be vine weevil, which enjoy lurking around containers: watch out for telltale munches on leaves and apply nematodes to keep them at bay organically.

All-year-round container combos for different aspects

Full shade

Ferns (Penlan Perennials does brilliant peat-free combos)

Mind-your-own-business

Narcissus ‘Pheasant’s eye’

Persicaria ‘Red Dragon’

Half shade

Hellebores

Heucheras

Muscari

Wood anemone

Muehlenbeckia

Sunny spot

Achilleas

Sedums

Dwarf alliums

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