I think any gardener would be lying if they said that planting wasn't the most exciting part of any garden activity! The rush of getting new plants and specimens into the ground can be intoxicating, a natural botanical high. Now that the Exploding Atom gardens structure is in, its time to start fleshing out the concept garden with plants. Armed with my planting plan and fresh from shopping this article details the planting of the 'Outer rim'.

Now I would usually argue against planting in the middle of a 30-year record heatwave. However, when you’ve got a hundred or so plants sat waiting to go in, you can’t really hold off as they frazzle in the 32-degree heat. So I’m caveating this article that where possible avoid planting in the middle of the scorching midday sun. Though the exception is when that scorching sun lasts for 3 whole weeks!

What is the exploding atom gardens outer rim?

The Outer rim of the Exploding Atom garden is probably one of my favourite parts of the design. Not because it has the most ridiculous name but it has allowed me to blend wild planting with an opposing design style. Formal and informal design at the same time.

Now I’m about to go all conceptual so get your rose tinted glasses, incense lit and some Sigur Ros on full blast. Are you ready? Ok, let us conceptualise!

The Outer rim signifies the shards of the Exploding atom. The debris that has been blasted out randomly from its red-hot core. I’ve interpreted this by using a really loose, wild and slightly chaotic planting palette. Using grasses amongst some shrubs and a stunning multi-stem Betula (White Birch). I want texture, height, drama and most of all winter interest as the plants in the outer rim die back leaving skeleton plant structures.

However, because the layout of the garden is symmetrical and a mirror image, the outer rim beds will mirror each other as you walk between them. Still with me? Brilliant.

Exploding atom garden wild border
Over time the plants will mesh together forming a mix of heights and textures

Planting List for the Wild Border

  • Crocosmia ‘Paul’s Best Yellow’
  • Nepeta nepeta
  • Calamagrostis ‘Karl Foester’
  • Molinia caerulea
  • Lamium ‘Hermans Pride’
  • Deschampsia cespitosa
  • Miscanthus sinensis ‘Morning Light’
  • Pennisetum orientale ‘Karly Rose’
  • Waldsteinia ternata

Planting a herbaceous border

Now you may be looking at the Exploding Atom Garden and thinking that you wouldn’t even know where the start with a planting a herbaceous border. So I thought it would be a good time to give you some tips if you’re starting a new garden on how to lay out plants for the best result.

Planting a herbaceous border
See how laying out your plants before hand allows you to check and make tweaks?

So no matter what styles of plants and species you are into there are a few universal rules that will get you the best overall look for a border.

  1. Ensure you have a mix of herbaceous perennial and evergreenĀ plants. I usually go with a smaller ratio of evergreen to herbaceous, such as 1:10. This gives some colour and structure during the winter months and a food source for birds throughout the year.
  2. Layer your plant heights. By layering varied heights in the border in graduation you can slow a visitor down to the garden. This also extends the interest. You don’t want a sore next from looking at ground cover one minute and then a 4m high tree the next!
  3. Remember the ultimate plant size. Whilst it may look great at first filling every space, the next year you’re going to be thinning and removing plants like nobodies business. So pay close attention to the ultimate plant size. More on that below.
  4. Lay out your plants before you dig them in. Stand back. Check. Tweak. Then get planting.
  5. If in doubt always use a planting plan. I say this all the time, but it’s far easier to do your research on paper before you hit the garden centre. By using a planting plan you can work out what’s going where and visualise it beforehand, saving time and money with wasted plants.

How to space plants out in a border

Now it may sound obvious to explain plant spacing. However, in the giddiness of getting new plants home many a gardener will have succumbed to planting with free abandon! Plant spacing is incredibly important for your garden.

Plant spacing for a border

By incorrectly spacing them you run the risk of:

  • Plants failing to establish as there’s too much competition
  • Having to remove plants during the season and relocating them
  • A messy squashed planting palette that is at odds with your garden
  • Increased chances of disease and illness spreading due to lack of airflow and space

By checking the ultimate height and spread (the width) of a plant you can work out how many you will need for your flower beds. Now sometimes I will move plants ever so slightly closer together when I know that certain species will respond well to this, Agapanthus a clear choice for a crushed squeezed environment.

By giving your plants time to breath you can also tweak and prune them as they grow into a shape of your choosing. It also means that watering is easier as you can see where you have or haven’t watered.

Border plant spacing

I also advocate that border plants, the ones that grow or spill near the edges of borders or paths, are placed away from the edge of a border. This again gives the plants time to grow, makes it easier to mow up to the edge and makes for a more relaxed look in the garden. Ignore show gardens and makeover shows where every inch is covered. Gardening is for the long-term and part of the fun is watching plants develop and grow!

Border planting
Placing border plants away from the edge is a better solution than cramming them in!

So there it is, the outer rim of the Exploding Atom Garden planted and ready to grow. The next stage will be the dark and moody ‘Purple Belt’ of the garden. Got a question on the Exploding Atom Garden or design in general? Why not Tweet, Facebook 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

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