6 perennials you should never grow in pots or containers if you want to maximise their potential – even if it is tempting

If you're on the prowl for container gardening ideas, then you are thoroughly spoilt for choice. Most plants thrive in pots, and although there are some bulbs you should never plant in pots, like Sicilian honey garlic and crown imperial fritillaries, on the whole, most perennial plants will live a very happy, albeit restricted, life in a pot.

As ever with gardening, there are a few exceptions to the rule. There are a handful of plants that will, at best, throw a tantrum if planted in a pot, and at worst, perish and die. Some perennials simply do not thrive in confined environments. Plants that prefer a deeper, cooler root run are off the list, and if you're a forgetful waterer, so too are those that require constant moisture levels.

Here we shine a light on six plants you should never grow in pots.

Wisteria

I adore wisteria and grow it against my garden wall here in London, waiting with bated breath each year for it to throw out its beautifully fragrant purple flowers.

If you're wondering how to grow wisteria in pots, then know this: it can be done, but your wisteria will live a far happier life in the ground, if it is possible for you to do so.

Wisteria vines are vigorous growers and can produce extensive root networks, so you will likely find your wisteria vine outgrows its pot every few years, requiring you to buy a larger and larger pot every couple of years to keep your wisteria plant alive.

What's more, wisterias don't need feeding when grown in the ground; they find it easy to access the nutrients they need. Though when grown in pots, you must regularly fertilize wisteria vines, adding an extra cost.

Astilbe

Astilbe, often referred to as 'False goat's beard', is one of those incredibly rare full shade perennials that delivers color to dark, dank corners of the garden.

Fantastic for shade-drenched beds, underplanting trees, and filling those gaps where simply nothing else seems to grow, astilbe can be relied upon to deliver great plumes of flowers even in the gloomiest of spots.

Though if you are looking for some of the best shade plants for growing in pots, maybe you're keeping your eyes peeled for the best plants for a shaded balcony or to squeeze into a shadowy courtyard, then be wary of astilbe, since its near constant thirst levels make it very difficult to please when housed in containers.

Astilbe thrives in consistently moist soil and requires ample watering. A moment's inattention, and container-grown astilbe plants will throw a tantrum from lack of water and will perish remarkably fast. Unless you are someone who can water astilbe religiously, it is best in a damp, shady flower border that retains water far better than a pot.

Eryngium

As forementioned, among the perennials you should never grow in pots include those that have a deep root system. Eryngiums fall into this category. A superb architectural plant with seedheads almost more beautiful than the flowers.

Happily, eryngiums can thrive almost anywhere and are extremely tolerant of poor and sandy soils, and since they require little watering, they're well-suited for drought-tolerant planting schemes. So far, they're sounding pretty suitable for container gardening.

However, whilst eryngiums might grow well initially in a pot, they will only reach their full potential when allowed to grow with a deep taproot. The height and spread of the plants will be stunted by living their restricted lives in a pot, and will need a large area to grow properly.

English Ivy

Very few perennials grow quite as ferociously as English Ivy (Hedera helix). It's quite the aggressive grower and climbs and spreads as much as possible, and since it's self-clinging, there's no need for man-made support - if it sees a surface, it will grow on it.

This habit has its merits, making it one of the best ground cover plants and fantastic for hiding outside pipes or covering a wall.

Initially, ivy may seem well-suited for growing in containers, since it has adventitious roots (roots that grow from the stems instead of below the soil). Although it's worth bearing in mind that ivy grows astonishingly fast, and once adult growth has established, it will begin to take over and engulf your container, and all surrounding containers in its leafy green foliage if left unchecked.

Even with regular haircuts, ivy grows too fast for a container space, so from an aesthetic perspective, and to save you the constant headache of keeping it contained to a small area, it is best planted in the ground.

Delphiniums

There are so many beautiful types of delphiniums, each as impressively tall as the next. They always look dashingly handsome as a back-of-border plant, but be wary if you plan on planting them in pots.

Tenielle Jordison, Gardens Content Editor at Homes & Gardens, urges gardeners to plant delphiniums in a flower bed and not in pots. 'Their roots don't do well with being disturbed, so having to repot your delphiniums if they outgrow a container is risky,' she explains.

'They also don't do well with restricted space. In the ground, delphinium plants can establish a much more settled, robust root system for stronger growth year-on-year. Not only this, but the height of delphiniums makes them susceptible to being knocked over in the wind, especially in pots. Planting them in the ground adds stability, especially when paired with a plant support.'

Shop garden essentials for potted plants

If you are restricted to growing any of these plants in pots, and still want to give it a go, be sure to stock up on these top rated container gardening must-haves:

Rest assured, though, that there are many other plants that will thrive, even prefer life in a pot, where it can be pampered and cossetted.

Though, if you are willing to tolerate the idiocrasies of these six plants, then by all means do attempt to grow them in a pot, just don't say we didn't warn you.