by Carol Bartlett | Oct 11, 2024 | Gardening Posts, Perennials
Perennials are beautiful and versatile plants that fill gardens with interest for many, many years. Often chosen for their spectacular free-flowering colour, you can also plant perennials for height, evergreen structure, scent, ground cover and more. We asked experienced gardener, Carol Bartlett, to share her knowledge about growing these hard-working favourites. Here’s her tried and tested advice…
Browse our full range of perennial plants for inspiration.
What is a perennial plant?
A perennial is a non-woody plant which lasts for more than two years. Hugely popular, they come in all shapes and sizes including tall, scented, climbing, winter-flowering and evergreen perennials. Mostly hardy, a few are half-hardy. Some are also herbaceous, which means they die back in late summer, eventually becoming bare earth over winter before producing fresh new foliage in spring.
If you’re looking for colour in your garden, perennials provide the full rainbow from pale pastels to hot reds. They include garden favourites like bright red/orange/yellow crocosmia, hardy and dependable geraniums, cottage garden plants with tall spires like lupin and delphiniums, long-flowering heleniums, bold coneflowers and the ever-popular clematis. Perennials offer great value for money. Once planted, they return year after year.
When and where to plant perennials
Spring is traditionally considered the best time to plant perennials, but you can plant them at any time from spring to late autumn. Many perennials are sold during the summer as garden-ready plants and add instant colour to your border. Good watering is essential to establish new plants, so spring and summer planted perennials will require regular top-up watering. Autumn is often overlooked as a planting time, but it’s ideal. The soil is still warm, and we get more rain.
Perennials are suitable for growing in borders or containers, adding colour and scent. Some of the best perennials for containers are agapanthus, dahlia, lilies, and lavender. A large container of hostas can also look lush and stylish, particularly in those shady corners.
The key to growing perennials successfully is “right plant, right place”. All perennials have preferred growing conditions, which could be full sun, partial sun, shade, moisture-retentive soil, or dry conditions. For a plant to thrive, you need to grow it in a spot in your garden that best matches those growing conditions. If you’re not sure about the conditions required, check our perennials resource page for information and advice.
How to plant perennials
As a rule of thumb, most perennials require humus-rich soil with good structure. Perennials, especially herbaceous perennials, put a lot of energy into growth and flowers each year and are best planted in good soil. There are always exceptions. Lavender and nepeta will thrive on thin soil, as will achillea.
Here’s how to plant a garden-ready perennial:
- Dig a hole slightly larger than the pot, say 5cm extra all around.
- Ease the perennial out of the container and free the roots so the plant is not compacted.
- Place in the hole at the same level as the garden earth.
- Backfill the hole, and firm well to ensure no air pockets. If roots grow into an air pocket, they can’t draw nutrients or water, and the plant may not thrive.
- Look up each plant to find out its height and spread. This helps you to gauge where in the border to plant, and also how close to surrounding shrubs and perennials.
- Water, water and then water again.
There’s one important exception. When planting clematis, ensure the plant is below the soil surface by about 10cm. Clematis prefers to be planted a little deeper.
How and when to prune perennials
The aromatic silvery grey foliage of nepeta is suitable for the Chelsea Chop
Image: Nepeta x faassenii from T&M
You can prune herbaceous perennials in the autumn once the top growth has died back. Alternatively, leave the top growth in place which will afford the plant (and insects overwintering in it) frost protection, and prune in the spring.
During the summer growing season, you can also cut back many perennials after they finish flowering to encourage a second flush of fresh foliage and flowers. Ideal for this treatment are hardy geraniums, alchemilla mollis, centaurea, lavender, heuchera, and nepeta. Deadhead your perennials regularly to encourage new blooms throughout the season.
If you want to make your perennial plants bushier, you could also try the Chelsea Chop. Carried out in May, the Chelsea Chop is simply a light prune of perennials, before they flower, reducing the plants by about one-third. This light prune makes the plant produce more shoots. It’s especially useful for plants which tend to sprawl, like nepeta. You can vary how you apply the Chelsea chop by cutting back some plants and not others. If you have lots of the same variety, this will stagger their flowering period. You can also chop back part of the plant, or chop the whole plant to reduce its height in the border. Adapt the technique as you wish to get the best out of your perennials. Plants suitable for the Chelsea Chop include nepeta, aster, monarda, lavender, echinacea, artemisia, sedum, phlox, helianthus, and rudbeckia. As a guide, it’s suitable for multi-stemmed perennials.
How and when to divide perennials
Ideally, you should divide your perennials every 3 years or so. You’ll know it’s time to lift and divide them if your plants aren’t flowering as well, or have bald patches in the middle. The best time to divide perennials is either in the spring or autumn. Here’s what to do:
- I always use a fork to lift the plant out of the ground to minimise damage to the roots.
- Inspect the roots. With such a wide range of plants, roots vary significantly.
- With smaller plants, such as geraniums, you can pull the root ball apart with your hands. Separate it into 2 – 5 parts depending on the plant size.
- For larger plants, such as Hemerocallis, the root may be quite large. This type of root is best separated by putting two forks back to back and prising the root ball apart.
- There are large plants with very tough, fibrous roots such as Agapanthus which require more force. Once the plant is out of the container, saw it into several parts using an old bread knife or a hand saw. It may seem brutal, but the plant will recover and improve after being divided.
- Replant in appropriate growing conditions, and water well.
Carol Bartlett’s five favourite perennials
I love perennials and grow many in my garden for colour and scent. A few of my favourites are:
- Leucanthemum because I love daisies and so do the bees. Easy to grow, and long flowering, I especially like the varieties with frilly petals such as L. ‘Crazy Daisy’
- Agapanthus for its large, spikey flowers in bold shades of blue and white. Agapanthus grows well in containers making it ideal for a patio. Agapanthus are also long flowering and belong to that exclusive group of plants whose flowers look good as they fade.
- Geraniums are a garden stalwart flowering reliably year after year. They come in many sizes and colours and you’ll find varieties tolerant of almost all growing conditions. There’s always space in my garden for geraniums that add colour throughout summer and into October.
- Sedum is a late-summer and autumn-flowering perennial. I’ve never had a garden without sedums. I love the rosy red and white varieties, which are wildlife-friendly and a magnet for butterflies and pollinators.
- Lavender, which I find irresistible for its intense shades of blue and calming scent. I like to plant lavenders next to a path to release the perfume, or on the patio so I can reach out and touch the flowers which are so tactile and wonderfully scented.
We hope this has given you plenty of help with choosing and planting perennials. Check out our top ten perennial plants for more inspiration and, perhaps try sowing your own perennial seeds for a satisfying challenge.
Carol Bartlett has been gardening for over 30 years creating many different types of gardens. Her website, The Sunday Gardener, was set up over 10 years ago to provide practical down-to-earth advice, especially for new gardeners, no matter what size their garden or vegetable plot. She also aims to inspire others to enjoy gardening and reap the benefits of being outside with nature.
Carol writes the website information herself, and most of the images have been taken in her gardens or those she has visited. The idea is to show plants in an authentic garden setting. Her philosophy is that gardening is a great combination of the therapeutic and practical. It is a cliché, but still true, the garden is a haven in which to escape day-to-day pressures. You can follow Carol on Facebook and Instagram and watch her helpful videos over on YouTube.
by Carol Bartlett | May 7, 2021 | Gardening Posts
There are lots of good reasons to grow drought tolerant plants. During hot summers the need for frequent watering is time consuming. Not to mention costly to the environment and your pocket too, should rainfall in your area fail to keep up with demand.
We asked The Sunday Gardener, Carol Bartlett, her advice on drought tolerant plants. Here are some of her all time favourites, some of which positively thrive on neglect…
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Carol Bartlett has been gardening for over 30 years creating many different types of gardens. Her website, The Sunday Gardener, was set up over 10 years ago to provide practical down-to-earth advice, especially for new gardeners, no matter what size their garden or vegetable plot. She also aims to inspire others to enjoy gardening and reap the benefits of being outside with nature.
Carol writes the website information herself, and most of the images have been taken in her gardens or those she has visited. The idea is to show plants in an authentic garden setting. Her philosophy is that gardening is a great combination of the therapeutic and practical. It is a cliché, but still true, the garden is a haven in which to escape day-to-day pressures. You can follow Carol on Facebook and Instagram and watch her helpful videos over on YouTube.
by Carol Bartlett | Aug 9, 2019 | Gardening Posts
Many people have a tough spot in their garden – too dry, too shady, or just too exposed to be able to easily grow plants that will thrive. Others have damp, boggy areas or frost pockets that present challenges to plant life.
We asked The Sunday Gardener, Carol Bartlett, to share her expert advice on tough plants for tough locations. Here are some of her top suggestions for plants with the stamina and staying power to fill your tricky spots.
Shrubs for exposed areas
A blustery corner of the garden could be the ideal spot for a tough shrub such as cotoneaster. There are lots of different varieties in this group of shrubs, and an ideal sized variety that grows to around 2.5m is C. Amoenus. It’s tolerant of all soil types and copes well with partial shade and blustery conditions. An evergreen shrub, its lovely white flowers in the late spring and early summer are attractive to bees.
These are followed in the autumn and winter with masses of red berries – a feast for wild birds, and especially loved by blackbirds. It’s a tough shrub and will grow wherever you plant it, except in wet conditions.
Another tough shrub which is very hardy and tolerant of most conditions is elaeagnus. Most attractive are those with variegated leaves such as ‘Limelight’ and ‘Gilt Edge’ which has the RHS award of garden merit. Equally tough, with bright variegation is Euonymus fortunei. ‘Emerald and Green’ which has golden green leaves, and ‘Emerald Gaiety’ with white and green variations are good varieties to grow.
If you’re looking for a tough shrub with flowers, Viburnum tinus is an ideal choice. It has pretty, white-tinged, pale pink flowers in the spring and it tolerates most soil conditions, sun and shade.
Buddleja davidii is another hardy and easy to grow shrub that’s tolerant of all conditions, except wet and boggy soils. Buddleja is often called the ‘butterfly bush’ as its aromatic flowers attract a wide variety of butterflies into the garden.
Grasses for exposed areas
As an alternative to shrubs, you might like to try some of the hardier plants and grasses, but bear in mind that windy positions will cause tall grasses like Cortaderia selloana (Pampas grass) and Miscanthus to shed their lovely plumes.
Stipa tenuissima (Mexican feather grass) is an attractive, compact grass that grows to around 35cm. Ideal in harsher conditions, and with masses of soft fluffy plumes, it combines beautifully with achillea in a dry spot. Achillea’s large, flat, long-lasting flower heads continue to look good as the flowers fade.
Another plant that combines well with shrubs or grasses is nepeta. Tougher than lavender, and tolerant of different conditions including semi-shade and damp, it brings clouds of blue to your borders, from pale mauve through to deep indigo.
For excellent ground cover and as an edging for paths, Alchemilla mollis tolerates full sun, full shade and everything in between. Extremely hardy (to -20 degrees C) and tolerant of all soil types, it’s an ideal plant for tough areas. However, you’ll need to keep it in check as it’s vigorous, almost to the point of being invasive.
Plants for dry soils and rockeries
In dry poor soils, or for the small spaces between paving slabs and in rockeries, Erigeron karvinskianus is an excellent choice with its lovely pale pink and white daisy-like flowers. It will grow in many awkward areas and, once established, re-appears reliably each year.
Equally tolerant of dry conditions, if provided with a sunny spot, is sedum. This group of plants contains many different varieties including larger, upright specimens such as Herbstfreude with its familiar red and rosy pink flowers so loved by pollinators, to tiny ground-hugging plants with small but attractive flowers.
Plants for dry shade
One of the trickiest conditions to successfully garden, and requiring a very tough plant, is dry shade. I recommend trying vinca, commonly known as periwinkle, which has lovely blue flowers to brighten up the gloomy areas.
Equally happy in these conditions is the English ivy Hedera helix. When mature this plant produces late autumn flowers that provide high quality nectar for bees and pollinators just when they need it, before winter hibernation. The flowers are then followed by purple berries loved by blackbirds, thrushes, blackcaps and wood pigeons. It’s a native plant with great wildlife value, as is Hawthorn, which will also tolerate difficult conditions.
With stunning lime green foliage, euphorbia is another ideal plant for dry shade. Varieties such as Euphorbia amygdaloides var. robbiae retains its lovely fresh, lime green leaves and combines well with the blue flowers of Vinca to provide bright colour in a dry shady area.
Plants for damp shade
A tough condition that’s slightly easier to accommodate is damp shade. One of my favourite stand out plants for a darker damp corner is Astilbe. The strong white plumes of Astilbe ‘Professor van der Wielen’ are particularly good.
Astilbe combines well with ferns and hostas which thrive in damp shade. Try planting some of the more slug-resistant hostas such as Big Daddy, Gold Regal, Liberty, Halcyon, and Silvery Slugproof to keep the pests away.
Conservatory flowers
Finally, are you fed up of composting dead and diseased conservatory plants? If the toughest place to grow successfully in your garden is your conservatory, take a look at pelargoniums. These non-hardy geraniums not only withstand the extreme heat of your conservatory – they positively bask in it. They’ll also survive the winter in an unheated conservatory. Tolerant and forgiving, just give them a regular water and occasional feed (tomato food is fine) and geraniums will flower away from March to November. I have to make myself cut them back in November when they’re often still in flower, knowing that this will improve the plant for next year.
Geraniums have many different flower types, some with amazing scented leaves, that will happily live in your conservatory for several years. When they get leggy, simply take a cutting and start again with a fresh plant.
Geraniums really brighten up a conservatory and are one of the few flowering plants which will take the very hot temperatures unscathed.
We hope this has given you plenty of food for thought when it comes to tricky areas of your garden. For more inspiration, check out our plants for a purpose resource page. If you need more gardening advice, find everything you need to know about growing drought proof plants on our hub page.
Carol Bartlett has been gardening for over 30 years creating many different types of gardens. Her website, The Sunday Gardener, was set up over 10 years ago to provide practical down-to-earth advice, especially for new gardeners, no matter what size their garden or vegetable plot. She also aims to inspire others to enjoy gardening and reap the benefits of being outside with nature.
Carol writes the website information herself, and most of the images have been taken in her gardens or those she has visited. The idea is to show plants in an authentic garden setting. Her philosophy is that gardening is a great combination of the therapeutic and practical. It is a cliché, but still true, the garden is a haven in which to escape day-to-day pressures. You can follow Carol on Facebook and Instagram and watch her helpful videos over on YouTube.
by Carol Bartlett | Apr 4, 2019 | Gardening Posts
Plant vegetables, herbs and flowers together for optimum results
Image source: Irina Fischer
Companion planting is the art of growing different plants together to achieve certain benefits, such as helping with pest control, encouraging pollination or increasing crop yields. With a little thought, companion planting can also create a feast for the eyes, turning a functional veg plot to a glorious thing of colour and beauty.
We asked The Sunday Gardener, Carol Bartlett, for her advice on companion planting. Here are some of her top tips…
What is companion planting?
RHS Kitchen Garden at Harlow Carr
Image credit: Lee Beel
Companion planting has long historical roots, harking back to a time when there were no chemicals to control pests or to feed plants, and gardeners relied purely on nature. In the 1970s, when organic gardening became popular once again, companion planting enjoyed a renaissance which continues to this day.
But there’s another aspect to companion planting which is equally popular: using contrasting plants and vegetables to create an aesthetically appealing kitchen garden. This style of planting is illustrated above, in this RHS garden at Harlow Carr where the veg plot looks immaculate and is full of colour. In and amongst the vegetables are sweet peas, nasturtiums, tagetes and lavender, creating a veg plot that’s both beautiful and productive.
It’s fair to say that recent studies have been less than conclusive about the direct benefits of companion planting. I view it as a way to deter pests while also making my vegetable plot more attractive. In this wider context, which includes the aesthetic look of the veg plot, perhaps it’s less important to measure the direct benefits scientifically.
How companion planting works: repel and sacrifice
The combination of orange nasturtiums and yellow chard is both beautiful and strategic
Image source: Peter Turner Photography
There are two types of companion plants: some are grown because their smell repels unwanted insects, and others are grown as a sacrifice to keep the main crop insect-free.
One of the best known combinations recently receiving tentative scientific approval is planting tomatoes together with French Marigold (Tagetes patula) to reduce whitefly. Marigolds contain a substance called limonene, and scientific data confirms that tomatoes grown alongside limonene suffer less from whitefly. It’s also true that tomatoes and tagetes make a colourful planting combination!
Another good companion for tomato plants is basil. They look and taste good together, and this scented herb is said to repel pests.
Plagued by aphids? Nasturtiums make good aphid traps. The flowers secrete mustard oil which lures the insects away from brassicas and other crops. In a similar vein, some people use French marigolds as slug bait – meaning they’re used as sacrifice plants to keep your lettuce free from slugs.
Strong smelling plants, such as lavender, mint and sage are reputed to confuse and repel aphids and other unwanted insects away from many vegetables, including carrots. The combination of alliums and carrots is often recommended, but given the tenacity of the carrot fly, I personally always use a physical barrier as well. I’m happy to plant alliums and chives around my carrots, but put my faith in a sturdy barrier!
Companion planting to attract pollinators
Borage is a beautiful, pollinator-friendly herb
Image source: RHS
We’re becoming ever more aware of the vital role of pollinators and bees to our food culture. Carefully chosen companion plants definitely help to attract pollinators to your vegetable plot, and the more pollination, the better the yield.
The English pot marigold, Calendula, is so easy to cultivate that it almost grows itself. Unlike the French marigold it’s of no interest to slugs, who ignore it, but pollinators like hoverflies, lacewings and ladybirds are incredibly attracted to its lovely zingy yellows and oranges. What’s more, Calendula will seed itself from year to year with no gardening attention whatsoever.
Want to increase your tomato yields? Encourage more bumble bees. In fact, bees are so essential to tomatoes that boxes of them are often imported into commercial greenhouses to work their pollinating magic. In your own greenhouse, chives are one of the best ways to attract bees and are ideal planted with tomatoes. A few pots of chives near the entrance and around your plants will welcome them in!
Another herb that’s a great friend of pollinators is borage, with its lovely delicate flowers that attract bees, butterflies, and hoverflies. But if I could grow just one plant to attract pollinators it would be oregano, beloved of all pollinating insects.
For more information about companion planting combinations, see the chart in our Companion Planting Guide. Looking for advice on how to attract pollinators to your garden? Visit our hub page to learn more about plants for pollinators, including tips on attracting bees, butterflies and other beneficial mini-beasts.
Carol Bartlett has been gardening for over 30 years creating many different types of gardens. Her website, The Sunday Gardener, was set up over 10 years ago to provide practical down-to-earth advice, especially for new gardeners, no matter what size their garden or vegetable plot. She also aims to inspire others to enjoy gardening and reap the benefits of being outside with nature.
Carol writes the website information herself, and most of the images have been taken in her gardens or those she has visited. The idea is to show plants in an authentic garden setting. Her philosophy is that gardening is a great combination of the therapeutic and practical. It is a cliché, but still true, the garden is a haven in which to escape day-to-day pressures. You can follow Carol on Facebook and Instagram and watch her helpful videos over on YouTube.
by Carol Bartlett | Mar 11, 2019 | Gardening Posts, Your Stories
Grow herbs to add to your garden and kitchen.
Image: DarwelShots
Anyone can start a herb garden, no matter how little space they have available. Some people create bespoke culinary herb gardens, while others tuck these flavour-packed plants into any empty space they can find. See all the ways you can grow delicious herbs at our herb hub page now.
We asked The Sunday Gardener, Carol Bartlett, for her top tips on growing herbs at home. Here’s her sage advice…
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Carol Bartlett has been gardening for over 30 years creating many different types of gardens. Her website, The Sunday Gardener, was set up over 10 years ago to provide practical down-to-earth advice, especially for new gardeners, no matter what size their garden or vegetable plot. She also aims to inspire others to enjoy gardening and reap the benefits of being outside with nature.
Carol writes the website information herself, and most of the images have been taken in her gardens or those she has visited. The idea is to show plants in an authentic garden setting. Her philosophy is that gardening is a great combination of the therapeutic and practical. It is a cliché, but still true, the garden is a haven in which to escape day-to-day pressures. You can follow Carol on Facebook and Instagram and watch her helpful videos over on YouTube.
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