This may sound bizarre, but Katy showed me this and some other pictures of her newly potted plants and I was surprised that she had different kinds of plants in the same pot.

It had never occurred to me to do that –  I always plant singly.  And now that we have been talking about it, she thinks I am insane.

She says it’s based on a magazine article she read years ago – you need a thriller, a spiller and a filler.

Thriller: some might go as far as calling these the “heroes” of the potted planting.  They’re generally taller things planted at the back of the container, or in the centre depending on where you intend to put the pot for viewing.  If the pot will be viewed from the “front”, e.g. if the pot is placed in a corner, then the thriller goes at the back.  If it will be viewed from all sides, e.g. a pot on a junction of garden paths, then in the centre.

Filler: these are shorter plants that will form the middle layer of contrast with the thrillers and spillers, so (obviously) they are planted in the middle of the pot in front of or around the thriller.

Spiller: the trailing plants that hang over the sides of the pot.  Clearly these need to be on the edge of the pot.

And then, of course, you need to work out whether the pot will be in sun or shade, and what your colour scheme is going to be so that you can choose the right plants.

And now for some science!

The science of light, and potted plant displays

The equator is the closest point on the planet to the sun, and it receives the most direct sunlight. As you move further away from the equator (your latitude increases) the curve of the earth takes you further away from the sun and the light you receive is less direct and therefore less intense.  And the change in sunlight affects the way that you perceive colour.

So let’s say you live in Edinburgh (Scotland – 55° 57′ N) and you take a vacation in Mumbai (India – 19° 4‘ N).

Among other things, you’d notice that the light is a great deal brighter than you are used to.  You might take a trip to Colaba and while you are there, buy a dress with a beautifully vivid colour pattern and wear it happily throughout your trip.

However, when you get home and view the garment in the dimmer light of Edinburgh, it will seem much brighter and probably too garish to wear at home.

In case you are wondering, this also applies to your planting – your perception of the plant colours will be different depending on where you live.

Your Mumbai plant pot may be filled with beautiful red flowers, but in Edinburgh, you might prefer pastel pink.

Unless of course you love red (as I do) in which case go for it!

And these changes in light quality also apply as the seasons change, so your colours may appear different in spring and autumn.

But it’s not just light, it’s your personal preference too.

Personal preferences in potted plants

Katy is at 35º 15′ N, and I am at 37° 48‘ S, so theoretically she has brighter sunlight, but I love the brighter colours – my spring/summer garden is a riot of red and yellow flowers.

If your pot is going to be outside, you should also consider your local wildlife.

I bought a new miniature rose the summer just gone (I suppose that would be a spiller), but it was successively possum eaten and dead within a fortnight (I was very sad).

However, my kangaroo paws (thrillers) are continually eaten and just keep growing back (bless them).

Probably not a good idea to mix the two of those – would a pot of possum edibles be a better or worse idea?

Or if you want to do your bit for the local bees, then blue and purple flowers.

Anyway, back to Katy’s pot.

She’s been doing this for a while and takes some liberties with the “instructions”.

This combination is based on “coral bells”, so she wanted plants that would go with chartreuse foliage, and provide a “natural” look in a wild, riotous colour combination with lots of movement.

Along with the coral bells, her thriller is the dracaena spikes.  For fillers, she has verbena, petunia and white euphorbia, and for spillers creeping jenny, verbena and euphorbia.

Putting together a mixed pot seems like a nice little weekend project – are you up for it?

We’ll be planting out our vegetable bed this weekend, so I’ve been thinking about how I could put this technique to use in a pot of herbs – all suggestions welcome.

Katy’s potted plants – thrills, spills and fills. Photo by C Dennison.