7. Balcony Roses: Thoughts on Pots (March)

Roses on a sunny patio in Greece: who says you can’t grow roses in pots?

So far, my four bare-root Drift® bare-root roses are nicely planted in their four matching square plastic pots along the railing on my balcony. I’m waiting impatiently for summer warmth to tease them into bloom.

My balcony pots are made of either plastic, ceramic, or clay terra cotta. There are good and not-so-good features of each.

For example, TERRA COTTA POTS are porous, and tend to wick moisture from the soil so you won’t likely worry about over-watering or root rot, and they will keep plants cooler than their plastic counterparts. I have just one of these. You may gradually notice a crusty white buildup on your terracotta pots due to mineral salt deposits or fertilizer in the soil. It’s known as “efflorescence”. This buildup is harmless but unsightly: it it bothers you, it can be scrubbed off using a solution of one part bleach to nine parts water.

PLASTIC POTS don’t “breathe” like clay pots do, so retain soil moisture longer than more porous clay does. Most of my current balcony pots are made of plastic and require less frequent watering than porous clay pots do. The biggest pots are ceramic. In my son Ben’s new rose garden, he has a number of very large ceramic pots that will become home to his own pre-ordered bare root roses.

Last year during our record-breaking heat dome, I still had to water each of my balcony pots every day to keep my summer annuals from wilting dramatically. I can only imagine how often I would have had to water had they all been in terra cotta pots!

The COLOUR OF YOUR POT matters, too. Dark-colored or black pots will tend to hold the sun’s heat and may stress rose roots during very hot weather extremes. The smaller the pot, the hotter they’ll feel, and the faster the soil will dry out. My four square plastic posts containing those four Drift® roses I’ve already planted are dark brown. So this means – even with a plastic pot – I’ll have to regularly check if they need water on hot days so those precious new rose roots don’t fry.

The SIZE OF YOUR POT is also important. Most rose growers say “the bigger the better” when choosing planters or pots, and recommend that pots should be at least two feet high and two feet across. But most of my pots are far smaller than that out on my tiny balcony. This means that the plant roots might outgrow their space – or does it?

Although I’ve read the same recommendation in a number of gardening books, my own experience in my former gardens tells me not to be afraid of snug root space. This may sounds like sacrilege to gardeners who are able to grow in large garden beds, but I once had a townhouse garden planted on just six inches of soil atop the concrete roof our underground parkade – the worst possible growing conditions imaginable!

This sounds odd, I know, but a combination of annual soil amendments (especially mushroom manure and compost to create the best plant-friendly environment I could, given my reality) – plus of course regular feeding – produced pretty amazing results for 15 years – and even won a national Gardening Life magazine contest in the Small Garden category! Even my spectacular 3-storey high Kiftsgate rambling rose climbed up to the roof and beyond – impossibly thriving in only six inches of heavy clay soil!

Of course, it’s always best to provide the least stressful and most favourable surroundings for any plant if you can – but I have been amazed over the years at which plants will thrive in less-than-ideal conditions. The biggest pot currently on my balcony is two feet in diameter. It contains a spectacular weeping Blue Atlas cedar tree that has tumbled up and over the railing since I moved here in 2007. I also have a wonderfully prolific pink hydrangea and a Virginia Creeper climbing vine happily living in their 15″ plastic pots. Most summers, I tuck 4″ plastic pots of bright red geraniums into bare pockets. They become tightly root-bound by the end of summer – and they still thrive. Geraniums, apparently, like being root-bound!

I know that roses are heavy feeders, and so with regular doses of special rose food this summer, I’m optimistic that those four matching plastic pots will work just fine.

Finally, a note about PLANT POT SAUCERS: these are the shallow trays that your pots sit in. They help to protect your balcony or patio floor by preventing water from spilling all over. Sometimes the plant saucers remain filled with water. This can be bad news for plants that could develop root rot if their lower roots are submerged in water. If this water sits for a long time, it can also invite insects to nest and multiply. Best way to drain this little pond of standing water is with a turkey baster. Seriously. Smaller pots can be lifted and the saucer simply drained out.

For several years, I’ve been filling my bigger plant pot saucers with gravel or pebbles. This elevates the bottom of the plant pot, which then sits on top of the layer of small stones so that the roots inside the pot won’t be soaking in a saucer full of water overnight.

For my four square rose pots (which narrow to about 9″ in diameter at the bottom), I couldn’t find any suitable square saucers, yet I still wanted to keep my pots tightly spaced together on their long narrow bench. I found 10″ silicone cake pans (in a saucy red colour!) that were the perfect size to fill with small beach stones. Our darling Everly Rose and I collected them four afternoons in a row using canvas tote bags on our walk home from her Grade 1 class.

Filling each silicone baking pan “saucer” with pebbles

The pebble-filled pot saucers beneath each pot to catch drips

Read the next essay in this series on balcony roses: