Night pollinators and garden lighting

How we light our gardens at night can have a massive impact on the wildlife around us and deserves to be considered carefully. We have hundreds of night pollinating insects that set to work as we sleep. Ensuring their work is undisturbed as much as possible by our garden lighting solutions is something we all need to aim for.

There is growing research into how damaging light pollution can be to nocturnal insect habits and gives an insight into to why there has been a steady decline in their numbers [amongst other factors like the loss of habitats, pollution, use of toxic chemicals and climate change]. Research, led by the late PhD student Douglas Boyes from Newcastle University, observed that the newer, white light emitting, LED street lamps have a far greater negative effect on local biodiversity and ecology then the older amber emitting sodium lamps. Some councils have started trialling part-night street lights to help reduce energy and carbon emissions. Lights are turned off between 1am and 5am which consequentially helps to reduce the negative impact on our night-shift pollinators. Callum J MacGregor is one of the main scientists in this field at the moment and has carried out research to show that just by turning lights off for part of the night will help re-address this balance.

I’m sure we have all observed a moth fluttering around a light at night. I remember as a kid on camping trips, the bathroom facilities were always a magnet for nocturnal insects. It is this behaviour, the allure of the bright light that distracts them [it messes with their navigational system] from getting their night-shift work done. Moths in particular are responsible for pollinating a range of plants and research carried out by the University of Central London suggests that moths are far more complex pollinators than bees. Moths will visit the same plants as bees, butterflies and hoverflies but will also visit plants that the day-shifters miss.

These are just a few UK based pieces of research that tell us how important nocturnal insects are and how bad white LED lighting is for our local biodiversity. There are plenty more papers out there and not just UK based; global research is revealing the same observations.

Pollinators are undeniably one of the keys to our existence and survival. The idea that we can individually choose to safeguard their future just by assessing what lights we put in our gardens is empowering. Garden and landscape designers have a little bit more weight as they can direct the lighting specifications of their client’s garden spaces. I have devised a checklist to work to for a limited impact scheme that will help our night-shifters crack on with their jobs…

• Do not use bright white or blue LED lights. Choose warm white to reduce harshness …after all [and this has to be said] it is a relaxing ambience we are looking to create in our gardens and not the mood of an operating theatre.

• Select lights based on lumens rather than wattage. Most outdoor lighting needs 100 to 300 lumens. The lower the lumen = the dimmer the light it emits = a much more subtle scheme.

• Reduce the number of light fixtures you think you might need. You don’t have to light up every tree, fence panel, wall or other vertical structure in your garden. Use minimal spotlights as they usually point light upwards. Experiment on moving them into a position that keeps the light from pointing directly up.

• Use downward facing lights and ground lights to illuminate steps and pathways … and don’t feel the need to light up every step, every other will be sufficient. Ground lights can also be set within a border edge allowing plant foliage to soften the light and create more shadow and interest.

• Do not keep lights on all night. Put them on a timer or only switch them on when you are in or looking out onto your garden space.

• Security lights tend to be the worst offenders for pollution. If you feel safer with them please select ones that are motion detecting and make sure that the lamps are safely contained within a unit…and again avoid the bright white/blue LEDs.

• One of my personal favourite ways of lighting my garden is by simple candle lit lanterns. A tea light will last around 3-4 hours before they go out, unless you buy the longer burning ones which will take you to around 8 hours. I hang the lanterns up in a tree, line my pathway and place on tables.

• Solar warm white lights is another option although the longevity of these is a bit hit and miss. You can also switch these off so you can control when they come on… ie maybe don’t leave them to come on every night 365 days a year.

Moss is not our enemy

Sometimes we have to make a real conscious effort to change our preconceived ideas of how our gardens should look and how we manage our spaces. How we feel about moss is probably one of the biggest perceptions to conquer. For years we have been ‘fighting back against moss’ using ‘moss killers’ and ‘moss destroyers’ to rid this nuisance from our lawns. It’s a controversial subject, the products manufactured to kill moss [using chemicals like iron sulphate or even glyphosate] is a massive commercial business; not to mention the lawn care companies and gardeners out there trying to do the best for their clients…

Yet moss is an ancient plant that can filtrate pollution from the air, it is responsible for some of the oxygen we breathe today and it provides a diverse habitat for a range of microscopic animals and organisms. It can help prevent soil erosion as its water absorbing qualities can soak up to 20 to 30 times its weight [Sphagnums; hence the importance of going peat free] which slows down run off and at the same time filtrates the water.

Let’s just skip back to the microscopic animals and organisms as they are the creatures that pack a hard punch when it comes to the health of our environment. Nematodes, mites, tardigrades, rotifers and gastrotrichs are some of the names of these creatures that are found to inhabit moss [they are also prevalent in our soil too]. It is these tiny invertebrates that are crucial in fertilising the soil, taking out pollutants from the air and absorbing carbon. Innovative sustainable solutions harnessing the power of moss are even popping up in and around our cities to help reduce the pollutants in the air we breathe; see Green City Solutions . So why are we still pre-occupied with killing it? Because our lawns and borders look better without it?

The moss that grows in our lawns tell us that there is moisture, shade and the lawn grass is lacking vigour. In the UK we inhabit the temperate zone of the Northern Hemisphere which correlates to wetter weather, combine this with lower light levels during the winters it is not surprising that most lawns will break out in moss. We will always be ‘fighting back against moss’ as it happens to adore our natural climate.

As a grower at heart, choosing the right plant for the right place is the most logical solution in dealing with all sorts of ground condition scenarios. Damp, wet, even waterlogged areas in people’s gardens is rife here in the North West and there are many design and planting solutions that will be far more appropriate and sustainable than turf. Bog gardens, bio-swales, wet woodland areas and yes, moss lawns, could provide so much more interest, habitat and actually play a role in cleaning up our environmental mess.

I know we are all consumed by so many responsibilities and it’s difficult to look after everything. But this one is really easy to action. Resist buying those moss killers, try to reset your perception of moss and maybe enjoy watching the blackbird collecting this life-supporting plant to make its nest.

Salvia x jamensis Nachtvlinder | Plants for pollinators

I love things that have more of a purpose than just looking good and this plant has this in bucket loads. I first bumped into this plant during a garden visit to Wollerton Old Hall, drawn by its delicate, rich velvety blooms, I bought one. At the time I had no idea how adeptly bestowed this specimen was, until quite recently listening to a pod cast via Sarah Raven’s Grow, Cook, Eat, Arrange.

I discovered a couple of years previously that planting this Salvia underneath roses was meant to be a good way to deter the dreaded black spot fungal infection. With a newly installed rose arch at the garden I maintain weekly and the year-old roses showing early signs of this disease I planted drifts of Nachtvlinder underneath to monitor its effectiveness. At the time I wasn’t sure what chemical aspects of the plant contributed to safeguarding against black spot…just that it was a good companion.

The podcast is very enlightening. To sum, it is believed that the scent make-up of this Saliva exudes sulphur which is a well-known fungicide used to treat black spot and other fungal infections in plants. In theory making this a super natural way to help keep our roses healthy. Some have very good results and swear by it. We may have planted slightly too late for it to have a massive effect, although the black spot hasn’t got any worse. For better results, it is recommended to plant the Salvias at the same time you plant the new roses.

The name Nachtvlinder translates to moth, night moth or night fly and usually Latin names tend to give us a clue as to something unique about the plant itself. We know it is an amazing plant for pollinators in general but the emphasis on potentially benefitting night time pollinators elevates this plant’s worthiness.

This particular Salvia is also hardy down to -15 so a good choice for our cold winters. This year we recorded -11 in Bolton so we definitely need to be careful in what we select for our gardens. If you do choose to grow this, leave all the foliage on as late as possible… and I mean late, do not trim back till at least the end of March/beginning of April and keep an eye on the forecast.

One last little icing on the cake to add… the petals of Nachtvlinder can be eaten. Use in salads and yes, sprinkle to decorate your home baked desserts.