COLUMNIST: ANDY PEASGOOD
When I first received and installed my green roof I was convinced that it was going to be a smooth journey, after all, I had done everything by the rulebook!
But there is no rulebook in nature. Yes, I had prepared the site well with the waterproofing, substrates, barriers, and drainage but ultimately, a living thing does not care for any rules.
The first year was a resounding success where the variety of colour, shape, and texture spread across the roof and I felt confident to show it off. “First time!” I thought to myself proudly. But I failed to do one essential bit of maintenance, which was to watch it.
Taking 10 minutes to walk around the garden and look at what’s happening is something I do regularly but for this project I completely forgot. Being on a roof, ‘out of sight, out of mind’ reigned supreme. I failed to pay attention and when I did remember to look, it had grown leggy from a period of high temperatures and heavy downpours. This wasn’t part of the plan and it reaffirmed to me that nature knows no rules.
Failure is the best lesson and in the garden, its teachings are great reminders or little experiences, so I acted quickly and tore the whole lot out. Decisive and confident that starting again was the only option, I was back to a bare roof. I later learned that I could have trimmed it all down and left it in situ where it would have happily rerooted itself for the following year, similar to self-seeding.
Back to the drawing board.
The second attempt for the green roof wasn’t quite as exciting as the first. In fact, it wasn’t exciting at all. I had received a reseeding kit from a commercial grower which consisted of a bag of substrate with sedum scattered through it and strict instructions to empty it on the roof, spread it, and leave it.
I did both and waited with anticipation for the roof to come to life like a child’s watercress experiment on a windowsill, but as the season passed nothing happened. When I think back to spreading the reseeding kit over the roof, I remember thinking that there wasn’t much sedum in the bag. Perhaps there were rambling or creeping varieties in the mix, perhaps I was impatient but, alas, nothing much happened.
One day, however, tiny red rosettes appeared at surface level and it revealed that some, and only some, sedum had rooted.
With a cautious smile, I once again returned to the drawing board.
The third attempt for the green roof is one of lessons learned:
If you are going to plant in unusual places, such as a roof, don’t forget to check in on it.
Don’t only research the ‘before,’ research the ‘after’ too. It may offer you suggestions that you can call upon later.
Listen to any suspicions you may have and use those suspicions to ask questions.
There can always be risks in horticultural purchases.
The weather can inevitably bring failure so don’t be in a rush to ‘fix’ things.
Don’t rush your choices, a simpler solution could be just around the corner but you just haven’t seen it yet.
Nature has no rulebook.
Equipped with these lessons, I found a small, independent, and reliable sedum grower that grew select varieties of sedum that were suitable to the areas of the UK that are more exposed to the cold and wind. Each variety is categorised into creeping, rambling, and ground cover with each variety having a thorough description. Best of all, they were plug plants (grown in single modular trays) and have young but developing root systems. I measured out the space and picked varieties based on growth habits, size, and colour. I drew out my plan, based on annual growth rates, and ordered the amount I needed which cost very little.
They were planted out in one weekend and my instincts told me, and still are telling me, that taking this patiently researched method where I’ve searched for a reliable grower, personally selected varieties to suit the space, and removed myself from the impatience of wanting an immediate green roof mean we may not see a fourth attempt - but watch this space!
Andy Peasgood is a keen gardener who enjoys design, plant combinations, and a ‘hands on’ approach to projects, as he shares the development of his garden.
A former Principal Dancer with Scottish Ballet and now a professional teacher and coach in vocational classical ballet training, Andy is most recently, a garden design student.
Follow more of Andy’s gardening journey on Instagram.