The Exploding Atom Garden is really starting to take shape. The structure and shapes are of the garden are established and the softer woodland outer rim is all planted up. So it's time to showcase the next area of the concept garden. The high impact moody goth border. This guide will give you some exciting plant ideas and combinations for a real show stopper garden border!

High impact borders can bring the wow factor to your garden. It doesn’t matter whether you have a postage stamp sized garden or a few acres, the principles are the same. Here in the Exploding Atom Garden, I’ve been planting up what I’ve nicknamed the ‘Moody Goth Border’. The aim for this border is to create drama and interest in direct contrast with the woodland border. This part of the garden links the wild woody outer rim with the red-hot core of the atom. By using a dark and sultry planting palette along with some unusual planting I’m aiming to create a real wow factor.

This will help the transition between the areas of the garden. So come along with me as I show you some intriguing examples you can try at home!

Using height in a garden border

If you have been following the progress of the Exploding Atom Garden you will have already seen the trees I’ve chosen for height and shrubs. However, it’s not just trees that provide height in a garden. By using herbaceous planting you can help extend the interest in your border by giving your eye more to examine in your garden.

Using height in a border prevents that one level of planting that your eye can quickly skip over. Introduce different heights and you then have a really dynamic and interesting border!

Exploding atom garden wild border
See how I using different heights in this border as it slows down your view?

The Purple border uses a number of tall specimens to bring height to these borders, separating the red-hot inner core, which I’ll be working on next, from the woodland light and airy outer rim.

By using height in your borders you can give the illusion of depth and help blur the boundaries, especially in a small garden. Meaning that you can also make a small garden look bigger!

Concept design of the #Explodingatomgarden

A top tip is to have a blend of heights from your tallest plants down to the ground cover. Whilst it may sound counter-intuitive but having a few really large specimens can make a garden look both bigger and more interesting. This applies even in small gardens. It’s all about scale.

Architectural plants

The purple border is really where I’ve gone to town with architectural plants. I’ve used them to draw focus and bring some real drama to this border. It’s where the fragments of the atom have been hurled out into space so I wanted planting that gave the feeling of sharp pieces.

Cardoons are an excellent architectural plant, if space allows!

You may have heard the term ‘Architectural planting’ before. Don’t worry if you dont know what one is. An architectural plant refers to any plant that acts as a focal point or structure in a garden. So if a plant has a unusual form, shape, texture or size in proportion to the garden it can be considered architectural. An architectural plant is one that stands out as a focal point and draws your eye to it.

Example Architectural Plants

  • Cardoons (Thistles)
  • Dicksonia antarctica (Tree ferns)
  • Angelica
  • Stipa gigantea (large statement grasses)
  • Agave or other hardy succulents
Angelica towering up in a border

Sometimes even the size of a plant can turn it into an architectural plant, such as a large established Fatsia japonica in a small garden in contrast to say a tiny 1lt version of the same plant. It must call out to you to go and view it or provide structure that pulls your focus in a garden.

Contrast with your garden planting

Now if I went ahead and simply used all dark and moody colours I’d just end up with a dark void of a border. Even with the most sultry plants, you need a bit of light or contrast to really make those colours jump out. A top tip for choosing plant colours is to make sure you always have a contrast colour somewhere in there. It amplifies the colours as it contrasts. A good example of this is to mix yellows in with purples, reds with greens etc.

Moody planting scheme
Can you see how the oranges jump out against the purple?

For the exploding atom garden, I’ve predominantly chosen purples and bright blues in the border. However, I’ve also included some silver and white to really make the blues pop out. Without these, it could look flat and uninspired.

More contrast between purple and orange

A good example of this is where I’ve used the dark purple of Angelica gigas which is in direct contrast with the light white of the Melica altissima alba (which is a airy clump forming grass). It has tiny white flowers which will pop out like popcorn against the Angelicas dark purple stems.

Top 5 Purple Garden Plants

The moody purple border in the Exploding Atom Garden is meant to be dark and brooding. So I’ve used a mix of common and also rare plants to achieve this look. By using a variety of imposing taller specimens with contrast it should bring a real wow to the border. Here are my Top 5 Purple plants to bring drama to your garden some are common others are quite unusual.

Cynara cardunculus if you want that real wow then a Cardoon is a must for your garden. Vicious looking leaves with a silvery shimmer. They bring both beauty and bite!

Cynara cardunculus

Salvia nemorosa ‘Caradonna’ – This is a show garden staple with its flowering season from May until the end of September. It’s one of the most hardworking flowers in the garden. It’s bright purple spikes bring a colour pop to any border and it’s also super drought tolerant.

Salvia nemorosa is one of the hardest working garden plants

Verbena bonariensis – This light and airy plant is a staple in show gardens. It adds instant height, has delicate purple flowers and is tough as old boots. It’s thin enough to let light through to plants behind it so it really can be positioned any where. It takes up such little room but brings so much!

Verbena dancing around the borders

Angelica gigas – Get ready, she’s here! Angelica is such a statement plant in a garden. This variety has Palma violet purple stems and large purple umbel flower heads. The umbel flower head stems from the Parsley family and means you get these almost side plate sized flowers. It’s happy in full sun or even partial shade.

Dried Umbel seed heads of Angelica

Actaea simplex – One of my favourite shade queens. This plant is happiest in damp shade, hidden at the back of a border. However, come September it sends up these huge white spikes of flowers bursting to life when everything else is coming to an end. If one plant symbolised Goth Rock it would be this one!

Dark and moody until the Autumn!

Why Autumn is the best time to plant a garden

Autumn is often overlooked as a time for planting up a garden. When suggested, it is usually met with a ‘why bother’ or ‘I’ll wait until spring’ response. However, you’re really missing a trick by not planting up your garden with herbaceous plants in Autumn.

By planting in the Autumn you can help ensure that your plants really go with a bang the following spring. This is because planting in spring helps to avoid stress on the plants. As the plants are coming to the end of the growth for that year, they will be able to focus all their energy in establishing roots. Rather than putting energy into flower production or leafy growth. The only caution is you need to make sure there no immediate chance of frost for the first month or so. If you start to plant in September or October you should be absolutely fine!

Barry’s not happy with the black plastic pots – more on that in the Youtube clip above

The benefits of planting in Autumn are:

  • Less watering to establish the plants as its a cooler temperature
  • Reduced stress and higher survival rates
  • Reduced pest numbers during the cooler months
  • Extends the flowering season the following year


So the Exploding Atom Garden is two-thirds of the way complete now. We have the light and airy woodland outer rim now followed by the moody punk rock purple border. So what is next? Well, the Red Hot Inner core will be planted up next. This area features the use of gabions for structure and focus as we enter the centre of the garden. Got a query on the Exploding Atom Garden or garden design in general? Why not TweetFacebook or Instagram me! Or you can check out the hashtag #Explodingatomgarden for more.


Catch up by going back to the beginning or other design diaries you may have missed!

  1. Exploding Garden Design Diary 1
  2. Marking out the Exploding Atom Garden Design Diary 2
  3. Planting the Trees in the Exploding Atom Garde Design Diary 3
  4. Shrubs and edging in the Exploding Atom Garden Design Diary 4
  5. Herbaceous planting in the Exploding Atom Garden Design Diary 5

Plants used for "Exploding Atom Garden Part 6 High Impact Garden Borders"

Architectural Plants
  • Acanthus hungaricus
  • Angelica gigas
  • Cynara¬†cardunculus
  • Valeriana officinalis
Plants for Height and Colour
  • Aster laevis arcturus
  • Anchusa azurea 'Loddon Royalist'
  • Centranthus rubra
  • Salvia nemorosa 'Caradonna'
  • Valeriana officinalis
  • Verbena bonariensis
  • Verbena bonariensis 'Lollypop'
Ground Cover Plants
  • Astrantia major Claret
  • Bergenia 'Bressingham Beauty'
  • Erigeron dunkelste aller
  • Geranium 'Johnson's Blue'
  • Knautia macedonica
  • Lychnis coronaria
  • Melica altimssima alba

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2 thoughts on “Exploding Atom Garden Part 6 High Impact Garden Borders

  1. […] easier to germinate plants. Secondly, I’m growing all of the herbaceous specimens for the Exploding Atom Gardens Hot Border. So the trial was a great way to test out recyclable alternatives and also stock my own garden at a […]

  2. […] my barrow around here there and everywhere so I found the clip a bit frustrating especially in the Exploding atom garden which is on an incline. I’m sure this can be tweaked by Henchman and is worthwhile to […]

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