More on ‘sustainable gardening’

23 January 2023

We’ve put ‘sustainable gardening’ in quotes as it means different things to different people. We use the term in two ways, really: 1) trying to use up as few resources as possible (which includes not wasting water, not using products that have to be mined, and so on); and 2) gardening in a way that increases the chances of our plants’ survival during the extreme weather events that are becoming more and more common as a result of climate change.

A lot of garden writers focus on ways of reducing watering, and on how to save rainwater, so as not to waste expensively-processed mains water. We do that, too – we have a couple of containers round the back that provide enough water to wet the compost we make, and as we’ve said here previously, we add organic matter to the soil so it’ll hold water well, meaning we don’t have to use the water tap very often. And of course, we have a lot of drought-tolerant plants in the gardens.

However, that’s only part of the story. After theΒ  very wet autumn and the couple of really cold spells we’ve already had this winter, it’s time for a few words on the other type of extreme weather events. Those drought-tolerant plants may be perfectly happy in heatwaves and droughts. but unfortunately, most of them really don’t grow well in cold, wet heavy ground. And that’s what we have in the gardens here – in a couple of beds there’s a layer of sand on top, but lower down, they have a layer of thick clay – just like the canal has, to keep water in.

So we’ll be really interested to see how many of our salvias, rudbeckias, hebes, eryngiums and other drought-lovers survive. We’d seen signs of life on them in January, two to three weeks after the sudden severe cold snap in December, but we won’t really know till April or so whether they’ve made it through the whole winter. We took cuttings of some of the plants in the autumn, so hopefully will be able to fill gaps; but in any case, we’ll no doubt see any gaps in the flower beds as opportunities to divide more plants and sow more seeds!

 

Leaf mould and dead leaves

December 04 2022

The team was out again yesterday, raking up more leaves from the grass around the flower beds. We filled about twenty-five more bags; most of them went straight into our leaf bin, as the level had dropped enough.

They’ll stay in the bin for about eighteen months. When we started making leaf mould, we used to turn the heap if we had time, but in fact it rots down pretty well without that. As we empty the leaf mould we just throw unrotted leaves, sticks etc. over the netting dividing the two bins, and it goes back round again.

The leaf mould is really useful as a soil conditioner. Over the last two or three months we’ve been putting it round many of the plants in the beds, so that worms will take it down into the soil over the winter; and in the spring, we’ll put another layer of it down as a mulch to keep moisture in the soil.

The remaining three or four bags of leaves were distributed round the beds as a protective mulch over the winter. We don’t do this till after Remembrance Day and Remembrance Sunday so they aren’t blown onto the paths, to keep the gardens as tidy as possible for the services.

This mulch of dead leaves does three things: it helps us keep the soil covered (so it doesn’t get damaged by heavy downpours or compacted snow); it’s great for wildlife – the leaves provide hiding and hibernating places for insects, which in turn helps feed birds over winter; and it helps protect the more tender plants (i.e. ones that can be killed by frost, like dahlias and salvias) by forming a layer of insulation over their roots. We still have one dahlia in flower!

And this year, we had a lot of bright red leaves from the Liquidambar tree in the middle of the grass – so they also gave us a last burst of autumn colour.

 

Unnaturally tidy – 2

18 September 202

A quick addition to the last post on why we cleared the wildflower bed so thoroughly – someone asked me this morning where we put it all πŸ™‚

Well, a lot of the dry stems and stalks are waiting to be incorporated into a pile on the preschool bed in a couple of weeks, to make a good hiding and hibernation place for insects. A lot of the greener things are in one of our compost bins round the back, ready to feed parts of the beds in a few months time, when it’s ready.

And a lot of the dead leaves, twigs and so on that had started to rot, have been tucked well under some of the larger lavender plants on the borders next to the wildflower bed. A lot of beetles like to live and forage among that kind of understory litter, so hopefully, they’ll find their way there.

This is one of the beetles we’ve seen a few times recently – it’s a thick-legged flower beetle (I love that name!). It’s a useful pollinator, too, spreading pollen as it moves from flower to flower.

Β© Bernard Dupont (CC BY-SA 2.0) via Flickr

Unnaturally tidy

15 September 2022

Usually about this time of year we explain why we’re leaving all the stalks and dead plants in the wildflower bed (to help insects through the winter, by providing hiding and hibernation places). We do cut down some of the really untidy stems, and we clear a few patches of earth to sow poppies into, but we do know it looks untidy. So it might come as a surprise to learn that we spent a couple of hours this morning clearing most of the plants, stems, dead leaves and so on out of that bed. This is why.

We knew that poppies thrive on disturbed ground; that’s why they spring up along new roads (often helped by being part of the wildflower seed mixes that are sown to help colonise the bare earth once the work has finished). That’s why we’ve cleared bits of that end bed every year.

But what we didn’t fully appreciate until recently was that poppies thrive on newly-disturbed ground, which is rather harder to achieve. A few years ago, a passer-by congratulated us on achieving a good display of poppies year after year, when they’d have expected them to gradually stop coming back; and we didn’t understand why that would be. He explained they grew best on newly-disturbed ground, and when we looked into it a bit further we realised that we’d have to radically change the way we manage that end bed. We decided to leave it alone for a couple of years, clearing only a few small areas, and not really disturbing the soil at all; and then we’d dig it over really thoroughly, in the hope that would count as ‘newly-disturbed ground’ for all the ungerminated poppy seeds that’ve been added to it over the last few years.

And this is the year we did that. Today we cleared most of the old plants out of that bed and forked the soil over quite deeply; we did leave a few clumps of perennial wildflowers, to continue the display after the all-too-brief few weeks when the poppies are in flower, but most of the earth has been turned over and broken up. The bed looks unnaturally tidy, and indeed we’re well aware that it looks unnatural without the mass of leaves and ground-cover plants like black medick and self-heal that have covered it in recent years. But hopefully, a few showers of rain, yet more poppy seeds sown and raked in, and a cold winter to nudge them into germinating, and we should have a great display of poppies once again next year.

Watch this space!

Watering (or not) – taking stock after the drought

19 August 2022

I wasn’t expecting to write a third post on watering after the two explaining what we usually do to conserve water, but the heat and drought this year have been exceptional, and their effect on the gardens is becoming increasingly visible.

While many plants will recover, we’ve become aware that it’d take an unreasonable amount of water and watering to keep some alive, and we’re having to think about which ones to allow to die, which is sad but necessary. But then, we can be more positive in thinking about which plants we should be growing more of – ones that can cope with this kind of drought, and even more importantly (as we have so little experience of this) which ones survive the kind of extreme heat we had in July.

The first to go, sadly, will be the carrots and flowers we’ve been growing with the preschool children – they’re lovely, but take a lot of time and water, and even then they haven’t thrived this year. Some of the staff from the local preschool said they’d water, we’ve been watering them, but the ones that are still there have barely grown. It’s time to call a halt.

A few French marigolds have survived but they’re struggling and barely flowering, so we won’t be watering them any more. It would be more realistic to work out what to grow instead, rather than keep plugging on with the watering cans in the hope they’ll have more than one or two flowers.

The nasturtiums the children sowed have done what nasturtiums usually do in this garden, i.e. take their time about germinating, put on a couple of leaves, then decide it’s too much trouble and just shrivel up. One managed to flower, and would have been glorious – a deep, vibrant scarlet flower – but the 40-degree heat was just too much for it. We’d been seduced by the constant mentions of nasturtiums as really easy to grow; not in these gardens, they’re not. Try something else.

So we won’t be sowing half-hardy annuals again – those are the ones that can’t go out till after the last frost – but for several of the last few years, that’s coincided with a period of very little rain, and they haven’t thrived.

Most of the perennial plants will come back, although they won’t have put on as much growth as usual, so won’t have spread themselves as they usually do. But they’re producing enough nectar for bees, and hopefully will recover fully over the winter.

One that probably won’t is bugle – Ajuga reptans – which has shrivelled up so completely that I can’t imagine anything will regrow. We’ll watch out for it, of course, but the time’s really come to replace it with something more resilient, like pot marjoram, which seems to be completely unaffected by either 40-degree heat or the drought; we’ve hardly watered it, but it’s just growing the way it normally does.

We did plant out a few cuttings of marjoram a couple of months ago, though, and they keep shrivelling up. They do recover if we water, but it would be better just to take more cuttings for next year, and to see that they’re well established over the winter, well before the droughts start. We chanced it this year; we lost; in future we’ll just see they’re planted out earlier.

We’ll also lift the rudbeckias (yellow daisies in the second bed up from the memorial cross), which need constant reviving. Bees do visit them when they’re not shrivelling up, but not much, and they’re hardly bee magnets. We’ll grow something else that is.

Watering – Part 2 Improving the soil

Watering (2) – Improving the soil

28 July 2022

When someone in the gardens asked me during the hot weather what we do about watering, my immediate response was that we make as much compost as we can, and add it as a mulch several times a year. Oh, and we add a thick mulch of leaf mould once a year, usually just before Remembrance Day.

I don’t think that was the response they were expecting. Didn’t mention taps or hoses or how often.

But actually, although they’re important parts of keeping plants watered, the most important thing is to keep as much moisture in the soil as possible, for as long as possible. So that’s what this post is about.

We’ve been adding compost and leaf mould to the beds for the last few years, and very, very gradually the soil’s improving, and crucially, it’s holding much more moisture now, for much longer, than when we started looking after the gardens. This means we don’t have to water much at all now.

We also need to improve the soil texture to cope with the heavier downpours and soakings we’re getting over winter most years now as a result of climate change. The spongier surface helps water drain into it when we need it to, rather than run straight off; and then the soil holds onto the moisture for longer in the much drier springs and summers we’re getting now.

We make our own compost, in a small empire of Dalek-type compostersΒ in the work area behind the gardens; and we have a huge leaf bin there. The leaf bin has two sections – one of them gets filled (literally) every autumn and winter, and the leaves rot down into usable leaf mould over the year. So we can empty the leaf mould from the second half over the year as it rots down, putting unrotted bits back into the other side to go back round again.

We also plant mainly shrubs (woody plants whose structure is there all the time, even if the leaves drop in winter) and perennials (plants that last for several years, though they often die right back in winter, and we have to remember where they are). Then in spring they start into growth again and fill the beds without our having to do anything but lift the occasional weed (leaving all the self-sown California poppies, love-in-a-mist, marigolds etc. to grow, if they’ve popped up in the right place).

We don’t really use bedding plants as until recently they’ve been grown in peat, they’re often pumped full of pesticides to keep them looking good for sale, and they die off at the first frost and have to be thrown away. And they’re bred to keep flowering, rather than to produce nectar and pollen, so they’re not much use to pollinators – which is probably a good thing, given the pesticides! None of that really fits in with our attempts to garden sustainably.

Though we do sow French marigolds with the preschool children, and plant them around the gardens. Unusually for bedding plants, they’re really attractive to pollinators; and the children love the process of planting them out, looking after them and watching them grow.

Watering – Part 1

22 July 2022

We’ve been asked a few times over the last few weeks how we keep the gardens watered, and after this week’s record temperatures and the ongoing drought, this seemed a good time for a post on the subject.

We do have access to a tap, and there’s a hose too, though I don’t think we’ve used it more than a couple of times in the last few years. There’s such a temptation to water everything when you’re holding a hose, ‘just in case’ – but water’s a precious resource, and we try to treat it like that.

For a start, we use watering cans rather then the hose (which is great if it’s been suggested you exercise more, and have a step counter – it’s about 50 steps from the tap to the beds – it soon adds up!).

The next most important point is that we only water selected plants – peas and carrots that the preschool children have planted, any annuals they’ve planted (we don’t use many annuals, and they’re usually sown direct and don’t need watering over the season); or any plants just coming into full flower, like dahlias, penstemons, and possibly roses, if they look like they need a boost. Although we don’t want to waste water, this is a public garden, and we try to keep some sort of a display going.

Most of our plants are perennials, and they’re put in as transplants, i.e. not grown from seed sown direct into the beds;Β  most of them are cuttings that we’ve grown on at home, so if they need watering, we can use rainwater from water butts connected to the house roof.

When we come to put them out in the gardens, we dig the hole, fill it with water, wait (there’s always something to do round there for five or ten minutes!), then fill it again. Then when the plant’s been put in and the hole backfilled with earth, we water it in to settle the earth round the roots. Then we brush a bit more earth over the top, which keeps moisture in and stops it evaporating too quickly.

We’ll then water that plant several times until it’s established – for a small French marigold (as grown from seed by the children from the local preschool), that might be two or three times in the first fortnight. For a larger plant, we might give it a good soak (@ 5 litres of water) once a week for a month, and also water it if there’s a drought or a heatwave. Once plants are established, we only water them in exceptionally dry weather.

This isn’t just to save water; it’s also because the soil here is sandy loam on top of clay, and we’ve mulched with compost (= spread it on top of the ground) a couple of times a year for about five years. So the soil is quite fertile, and grows good lush foliage. That looks great, until we have excessive heat or a drought, when the lush foliage will wilt much faster than it would in plants grown on poor soil, and not watered much. The drought garden on West Street is a great example – it looks great all year round, but particularly when there’s a drought, the plants cope with the heat much better than they do in gardens with richer soil.

We’re also looking at adding a few more plants that cope better with heat and drought, like salvias and sedums – with the effects of climate change very much here now, we’re going to have to learn how to adapt our gardens.

A welcome change of emphasis

20 July 2022

Every year in about mid-July we have a visit from the Britain In Bloom judges, as this garden is part of the Leighton-Linslade entry for the competition.

A year or two ago we checked the criteria against which entries were marked, as the RHS ‘Garden’ magazine has mentioned that environmental aspects were going to have more weight. We were delighted, as we’ve always tried to garden sustainable, for example making a lot of garden compost and leaf mould to improve the soil and hold moisture in it; growing appropriate plants in the right place; and watering selectively and only when necessary.

It seems a bit churlish that when the garden’s always been awarded a Gold, we’ve still felt disappointed that the judges have mainly been concerned with how many flowers there are in bloom when they come round. And we try hard to see that there are, which is tricky as the main June flush is usually over, while the plants that will flower well into autumn won’t have started yet. But we’ve always managed it, and always been a bit disappointed that the long-term, environmental things we do haven’t really been commented on.

sometimes it’s felt as if we should just go out and buy loads of bedding plants, and never mind about sustainability and pollinators!

So this year, it was a very welcome shock when the first question we were asked was about how we were watering in the drought, and the rest of the conversation showed that they really understood and wanted us to be the things that are just part of the way we garden here. But we were so surprised that we forgot to mention most of them – I remember muttering something wishy-washy about how we grew mainly perennials, and only watered selectively (that at least would have been obvious – we’d been round there at 7 that morning watering the plants that really needed it, so they’d be fresh for the judges; and the marks on the ground showed that we weren’t just watering indiscriminately.

We’ll know in a few weeks how the judges assessed us; but in the meantime, those conversations have sparked a lot of thinking about what we should be growing here, now that droughts are more frequent and particularly, now we’ve had the kind of temperatures we had this year. Sadly, we’re going to have to let some plants die – but we’ll learn from it, and replace them with even more appropriate ones.

Watch this space!

Unintended consequences

18 July 2022

Over the last couple of weeks we’ve been watering a bit more often than usual.

This is mainly because there are more new plants to water, mainly the nasturtiums and French marigolds that the preschool children weren’t able to plant out until a week or two ago. We usually water plants a few times after they’ve been put in, to help them get established quickly.

We’d also mulched most of the beds with the contents of one of the compost bins, so all in all, the ground round the new plants was pretty soft.

We’ve noticed over the last couple of week’s that something’s been digging holes in some of the beds during the night. This morning we realised that all the holes are near recently-planted flowers. It’s just dawned on us that watering frequently + mulching with compost = very soft ground – much easier to dig in!

And this morning, we found badger poo in the hole next to one of the uprooted plants – so now we know the culprit, too. Not quite the wildlife we were expecting to encourage into the gardens, but very welcome all the same!

Moving into the second half of the year

Moving into the second half of the year

10 July 2022

Horticulturally speaking, that is. We’re seeing the end of the great rush of flowers we’ve enjoyed over the last few weeks, as those plants die back or are cut back, and the ones that will take us through into autumn are just getting ready to flower. There’s quite a lull at the moment, which usually lasts till late July, and then the rudbeckias, dahlias, heleniums and geraniums really come into their own.

We’ve thought about raising and using bee-friendly bedding plants to fill the gaps as the spring flowers fall back, but generally, we find the gardens work better when we leave them. Many of those gaps will be filled as the plants we’ve cut back begin to regrow; and in most of the others, we’ll be putting in some new perennial plants once the customary July – August heatwave and drought are over. It wouldn’t be very sustainable to be planting out the penstemons and salvias we’ve been growing from cuttings, when the temperatures are in the mid-twenties upwards, and when we’d have to be watering them every couple of days. Come September, they’ll more or less look after themselves.

That’s the ‘as a rule’ version – but of course, rules are made to be broken, and in this case it’s because the preschool children have been sowing and planting French marigolds and nasturtiums, and watering them enthusiastically (along with everything else within reach). Both these plants grow and flower well, and most importantly, bees love them.

More sowing

Sowing the first batch of nasturtiums

 

The children have put quite a few in the bed they look after, alongside the carrots they’ll pick in the autumn term, and the annuals just starting to grow from the seeds the children sowed a few weeks back. They’ve also planted a few of them in gaps in the other beds – look out for the marigolds in the front bed, nearest the large conifer, and in a couple of other places in corners of beds nearer the car park. They’ll provide a little more colour as the garden revs up for its usual summer-into-autumn display.

Planting a few more flowers in the preschool bed