Bee Hotels and Seed Bombs – are they worth it?

Occupied shop-bought bee hotel. You can see the tubes which have been filled with leaves by a leaf-cutter bee.

A few years ago you would have found me at various events at work, helping visitors make bee hotels from wooden boxes and bamboo canes and praising their benefits to solitary bees, or mixing seeds with clay and compost to encourage people to ‘bomb’ their gardens with wildflowers for pollinators. And whilst I did so, I wondered if they really were the answer to saving our invertebrates. There was no doubt that the bee hotels did work, as we had seen many occupied with the holes of the bamboo canes sealed up with mud or leaves. However, there wasn’t any research on whether they were a good idea, at least not that I could find, and the trend grew – there’s now a whole array of insect hotels and seed bombs in most garden centers as well as being found online.

Home-made bee hotel from a mixture of reeds, bamboo canes and a wooden box.

This month, Karin Alton and Francis Ratnieks published a review of these products in the journal Bee World, and considered whether they were beneficial or just another trend. Below I look at some of their findings but you can find the full paper here if you’d like to read further.

BEE HOTELS

Solitary bees, unlike the familiar honeybees, don’t live in social groups. They often nest in either holes in the ground, crevices in the mortar of brick walls or hollow plant stems. The concept of bee hotels is to replicate these niches and provide a habitat to raise their young. However, often these bee hotels aren’t made to their required specifications; many are produced abroad and so the hole sizes aren’t suitable for our native bees, some don’t have a back and act as a wind tunnel, and the length of the tubes aren’t always appropriate. Research has shown that for the species Osmia bicornis when the tube lengths are less than 130mm there is a sex ratio shift towards male bees, and that 150mm tubes are the optimal length.

Mining bee, Andrena sp.

Another issue is that bees wouldn’t naturally congregate in the same densities that can be found in bee hotels – especially the larger ones. Solitary bees can be predated on by parasitic wasps which you may sometimes see scanning the side of your house searching for a masonry bee nest. Bee hotels offer easy pickings for these wasps as once they have found one nest they can go on to predate on the ones near by too – potentially having quite a detrimental impact on the local population of the bees using the bee hotels.

Ruby-tailed wasp, Chrysis sp. is a cuckoo wasp which lays it’s eggs in the nests of mason bees. The young emerge and consume the hosts eggs and young.

Bee bricks which are marketed as being a permanent solution to be added to buildings and developments were also considered in the report and the general consensus was that whilst they aren’t great for bees, they make great (expensive) spider habitats!

An elaborate bee hotel at the Hampton Court Flower Show 2015.

SEED BALLS

So what about seed balls? These can be bought online and aren’t particularly cheap – you can get many more seeds for your money buy buying seed packets. However, the fancy tin and novel idea of throwing the seed balls around definitely has an appeal. But do they work? My daughter was bought some one year, and we found they didn’t’ germinate at all, and the reviews online used in the report suggest the same.

Rusty Berlew, described as a ‘master beekeper’ explains how the sites where the balls are thrown often aren’t suitable for the seeds. When I looked at the ‘Bee Mix’ it lists some of the species which include ‘Birdsfoot Trefoil, Foxglove, Red Clover, Viper’s Bugloss and Wild Marjoram’ – but I know from experience germinating these species from seed in a greenhouse, that viper’s bugloss requires very different conditions to foxgloves, marjoram and clover and birdsfoot trefoil. Foxgloves are woodland plants whereas the others are more suited to meadows and open grassland. So whilst yes, they are all good plants for bees, they all require quite different conditions to thrive.

Bees love foxgloves
Viper’s bugloss on Hove beach. Quite a different habitat to that of a foxglove.

In all, the report really highlights that there is much more research needed to show if any of these products are beneficial to wildlife, or certainly to measure the negative impact they may potentially have on populations.

In the meantime, if you want to help wildlife, you’d be better off buying a bag of seeds suited to your garden, leaving dead plants and leaves over winter and providing log piles – and they’re all much better for your pocket too!

Put down your phone, take a moment to look.

It’s just a few weeks away from the Royal Norfolk Show and today whilst the children were either at school or nursery I took the opportunity to get away from the office and spend the day outside in the garden, potting up plants ready for the pollinator area at the show.

I moved some strawberries and herbs into some beautiful vintage style crates and began tending to the weeds in front of the house where my vegetables are growing. Just to note, I’m not usually one to call a plant a weed as most ‘weeds’ have a great wildlife value, but these were getting so out of control the potted plants were beginning to be shaded out! – and besides, it was mostly rye grass and creeping buttercup, the latter of which I have plenty of in the wildflower border.

As I was clearing the area around our rather humble tomato plants, casually out of nowhere appeared a ruby-tailed wasp – Chrysis sp. and settled on the wall in front of me. Now this might not sound too exciting, but I’ve been wanting to spot one for years after seeing everyone post their sightings in the Bees, Wasps and Ants Facebook group. And there it was. Scouring all the little holes in the brickwork of our country cottage, looking for mason bees to parasitise. Beautiful (in a somewhat morbid way).

IMG_8763.JPG

Ruby-tailed wasp  (approx 10mm)

I managed to catch the wasp hoping to get an ID on the exact species, but they are hard to differentiate unless you look under the microscope and I didn’t want to kill this beauty today so I let it go. But it made me curious – what else was in the garden? The sun was shining and it was definitely a good bug-hunting day, so I started looking. There were so many bees visiting the flowers; mason bees, bumble bees, carder bees and those really tiny black bees. There were hoverflies, beetles, other beautiful wasps, butterflies, damselflies.

I had read a Facebook post earlier in the day about nectar robbers and that with some long tubed flowers such as the comfrey below, the bees (especially Bombus terrestris and Bombus lucorum in the UK) would steal nectar from little holes near the nectary as they don’t have tongues long enough to reach down the corolla. They either create the holes  themselves (primary robber) or use holes already there from previous robbers (secondary robber). Sitting watching the bees in our comfrey patch I noticed this exact behaviour and even managed to catch a bee at it on camera below – you can see it’s proboscis poking into the flower! In the top photo you can clearly see the little holes close to the sepals. This method of taking nectar is called robbing because the insect doesn’t come in contact with any of the flower’s reproductive organs and so doesn’t facilitate pollination. They are simply stealing the good stuff without giving anything back to the plant! Cheeky.
IMG_1173
IMG_1161

 

I’m still learning to identify invertebrates, but I’ve definitely caught the entomology bug (pun intended). I was really enjoying sitting in the sunshine, soaking up some much needed vitamin D whilst trying to get as many photos as possible of the insects so I can get an ID later and add the record to iRecord. I lost myself for a good couple of hours without realising and before I knew it it was time to collect the children.

I wont always admit it but I am quite often stuck to my phone. Either from working or socialising, I do forget sometimes that there is a world away from that bright screen. Today I managed to remind myself that some of the best days are missed with a phone in your hand. I’ll be making more of an effort for technology-free days and turn my eyes towards the flowers,  the insects and the world outside. You should too 😉

Here are some of the photos from today… I’ll add the ID of each insect as and when I have it confirmed.

x Larissa x

 

Is Nemasys harmful to bumble bees?

Recent study finds consumer biological control lethal to bumble bee Bombus terrestris in laboratory tests

For many years, gardeners and horticulturists have been using biological control products as a means to eradicate garden pests such as weevils, carrot root fly, thrips and slugs. Many gardeners, including myself, have used these products as a more natural pest control over ‘nastier’ chemical alternatives, but a recent study has shown that these seemingly harmless nematodes could pose a threat to the invertebrates gardeners do like to see and actively encourage – such as bees.

Scientists at Liverpool John Moores University, found that entomopathogenic nematodes in two Nemasys products; ‘Grow Your Own’ and ‘Vine Weevil Killer’ were lethal to the bumble bee Bombus terrestris in controlled laboratory experiments. Results showed high mortality in bees exposed to soil containing nematodes from each of the products. These products are both currently widely available and largely unregulated.

Entomopathogenic nematodes are a parasite, causing death in their hosts through an association with bacteria. Juvinile nematodes are infected with bacteria in the soil then seek and enters it’s host, such as a weevil or moth larvae. The bacteria causes septicemia and kills the host, providing a food source for the nematodes before they proliferate, sending more infected parasites out to find their next victim.

This study has highlighted the potential threat that these methods of biological control could have on our wild bee species, especially those such as Bombus terrestris in which the queen often overwinters under the soil. Worryingly, due to the delay between infection and mortality, if the nematodes are able to proliferate in the dead bees, there is a risk the whole colony could become infected.

Further field research is definitely needed into the safety of available biological control products on non-target species, and the effect that such products have on species outside of the laboratory.

The full article can be found here  in the open access journal PeerJ. Thank you to Steve Head from the Wildlife Gardening Forum for sharing this in the latest newsletter.

-Larissa

Header photo taken in the Natural History Museum’s Wildlife Garden.

Gathering inspiration

The summer holidays have been here for a few weeks already and it’s been quite busy. So busy the garden has become slightly overgrown and neglected. When I went on maternity leave I had envisioned lots of free time to lay in the sun and read books, potter in the garden become a lady of leisure. I was very wrong, and with the eldest off school as well, the garden has definitely taken a backseat.

IMG_5030

The Garden before the summer holidays – relatively tidy!

At the beginning of the holidays the kids and I spent a week away in Norfolk visiting friends and family leaving my partner in charge of the garden. While we were away it gave me a chance to pinch a few ideas and get some inspiration from other people’s gardens. My Dad has recently become quite keen on attracting wildlife to his garden and had added a few insect hotels since our last visit, one of which was being used by a leaf-cutter bee.

IMG_5228

A couple of holes have been blocked off with vegetation – suggesting a leaf cutter bee has been busy.

I was also quite impressed with my Dad’s use of pots in their small garden. Without the pots, there wouldn’t be nearly as much colour. A great idea for a rented garden, especially as the plants are easy to take with you if you need to move. He even had a pot with wildflowers which the bees were enjoying. I picked up a box of all white wildflower seeds at hampton court which I am saving for next year. I was going to sow them into the flower border out the front to create a white garden, but I think I might sow them in a pot. This also might protect them from the slugs too.

IMG_5229

Wildflowers grow in the pot below an ornamental tree

IMG_5231

A nice arrangement of pots can bring splashes of colour or year-round foliage and structure

We also went to visit my partner’s mother who has a beautiful cottage garden, as well as a vegetable patch. The flower beds are gorgeous and look like they belong in a Gardener’s World feature. I also love that there are surprises around every corner; a hedgehog house, and old wheelbarrow filled with plants, raspberries and blueberries hidden in the hedgerow and magnificent tomato plants in the greenhouse! The tit boxes were used this year and so were the bat boxes – but by tits too! Looking at the veg patch also made me realise a mistake I had made with my own at home – I hadn’t grown enough peas!

These flower beds have inspired me to extend ours for next year

These flower beds have inspired me to extend ours for next year

Blue tits using their nesting boxes earlier in the year

Blue tits using their nesting boxes earlier in the year

P1000262

The Vegetable patch – peas protected by netting earlier in the year. By the time we visited they were doing really well.

 

When we got home I was please to find the garden not only alive – but thriving. Having had quite a few days of rain the vegetables had exploded and everything was doing really well. Lots of different plants had also flowered including the purple loosestrife Lythrum salicaria (one of my all-time favourites) and teasel Dipsacus fullonum, both growing by the pond.

IMG_5256

The vegetables had grown a lot while we were away

The vegetables had grown a lot while we were away

Bees love teasel

Bees love teasel

As August has progressed, much of the time in the garden has spent harvesting the crops, but more on this later.

One final note – while we were away my partner spotted what we are pretty sure was a silver-washed fritillary in our garden. A first record for us and one I have yet to see myself.

photo

 

 

5 Easy Ways to Help Pollinators in your Garden

For Pollinator Awareness Week here’s a quick guide on ten ways you can help pollinators in your garden whether you rent it or not.

1 – Plant as many different pollinator-friendly flowers as you can

Variety is key. The more different flowers you plant, the more likely you will attract a range of different pollinators. For example, studies have shown that bees have gone to marjoram flowers, whilst butterflies preferred Bowles mauve. When you are out take note what plants are buzzing with bees, hoverflies and butterflies and remember that there are many more plants out there than buddleia to attract these beauties!

Bees love alium flowers too

Bees love alium flowers too

2 – Aim to have flowers from early spring to late summer/early autumn

By having flowers in your garden throughout the season you will be providing food for the early pollinators as well as the ones still taking advantage of the milder autumn days. Primroses Primula vulgaris are a great plant for spring pollinators whilst ivy Hedera helix is an excellent late-flowering plant.

Native primroses are edible too!

Native primroses are edible too!

3 -Leave the lawnmower in the shed

By leaving the grass to grow long (or even just a little patch) will help to attract butterflies such as meadow browns, speckled woods and ringlets who use grasses such as cocksfoot Dactylus glomerata as a larval food-plant. Grass also provides a home for many other invertebrates too as well as creatures such as frogs, toads and slow worms. I keep finding many teeny froglets in our long grass.

IMG_4896

Our patch of long grass at the back with a mown path (and campfire!)

4 – Plant a mix of native and non-native plants

Many of our pollinators have adapted to use our native plants either as a nectar source or as a larval food. Plants such as the ragwort Senecio jacobaea attract specialist species such as the cinnabar moth, whilst there are many native plants used by our butterflies to lay their eggs on and feed the caterpillars. A couple of good lists of these plants can be found here and here.

IMG_4854

Suspicious eggs (probably large white butterfly) found on the kale growing in our veg patch. Turns out I am the only one in the family who likes kale, so I’m happy to share it with the butterflies!

Caught in the act!

Caught in the act!

I just looked out of my bedroom window to see this gatekeeper on the ragwort. Luckily it stuck around for me to take a photo!

I just looked out of my bedroom window to see this gatekeeper on the ragwort. Luckily it stuck around for me to take a photo!

5 – Make a bee hotel

Bee hotels have become very popular and can be found in lots of stores and supermarkets which is great. However, they are also very easy to make too. It is really as easy as drilling some holes in wood or filling an empty bottle with bamboo. The key thing to remember is to make sure that the holes or bamboo are at least 10cm long. There are lots of great tutorials online such as this one or this one.

Made by my daughter from common reed and a plastic bottle

Made by my daughter from common reed and a plastic bottle

Another bee hotel made by my daughter, no visitors in this one yet.

Another bee hotel made by my daughter, no visitors in this one yet.

Add any of your own tips in the comments below!

Choosing Garden Plants for Pollinators; Natives or Non-natives?

This week (13th – 19th July) it is ‘Pollinator Awareness Week‘ and a perfect time to discuss the different plants that we can, as gardeners, provide for pollinators in our own little patches of green space. I’d like to to so by looking into some of the different native and non-native plants in my own garden which are often alive with the buzz of busy bees.

Why do we need to help pollinators? Pollination of our crops is an essential ecosystem service that we just can not do without and pollinators do this job for us for free. The term ‘pollinator’ covers a wide range of invertebrates including bees, butterflies, moths, flies, hoverflies and wasps. There are thought to be over 1500 different species of pollinators in the UK.

The most well known and frequently discussed group are the bees of course. There has been a lot of research over the last few years into the notable decline of bee populations with theories ranging from habitat loss, climate change and the use of neonicotinoids – a group of insecticides thought to effect bees – however, other pollinator groups are also suffering from similar environmental and anthropogenic stressors, so by adding a range of plants to suit different pollinators is in my opinion, a really good start in helping these important creatures.

Lungwort flowers early and the bees loved it this year!

Lungwort flowers early and the bees loved it this year

It has long been debated whether you need to plant native plants and have a wild and ‘weedy’ garden for wildlife or whether you can still attract wildlife with garden exotics.

Studies have found some non-natives to be useless to pollinators because the flowers are either nectar poor, too fussy for the insects to reach the pollen or the flowers are too long for the bees to get their tongues in. The RHS found in their ‘Plants for Bugs’ study that this isn’t the case for all non-natives and that some were as good as, or even better than the native plants chosen. It was at a Wildlife Gardening Forum conference a couple of years back that I heard all about this research and was swayed from being a dedicated ‘native only’ advocate to considering alternative garden plants.

The two plants that really stood out at the time were the native hemp agrimony Eupatorium cannabinum and the non-native garden plant Bowles mauve everlasting wallflower Erisimum linifolium. Both of these plants are excellent for pollinators and for me are definitely on the list of essentials for the garden. My Bowles mauve are awash with insects and also fill a space in my rockery/herb garden on my patio, providing a constant splash of colour throughout spring and summer.

Bowles mauve flowers in tall spikes which can last for the whole season

Bowles mauve flowers in tall spikes which can last for the whole season

Hemp agrimony is a native wetland plant, which is suited to damp areas such as fens or pond margins. It will however also grow in dry areas making it ideal for garden flower borders too if you don’t have a pond. I tried growing hemp agrimony by sowing seeds around my pond last year but had no success which is surprising as this plant can be invasive so be prepared to manage it if you have more luck than me. This year I planted hemp agrimony plugs around the pond but these seemed to be smothered by the other plants and I haven’t had any flower. As a last attempt, I put the final few plugs I had into a basket planter and placed at the edge of my pond. So far they haven’t died and hopefully will flower next year.

Untitled-1

Hemp agrimony

Another non-native plant which I think is an essential is red valerian Centranthus ruber. An introduced species now naturalised in the UK, it is great for pollinators, easy to grow and looks beautiful too.

Red valerian about to flower

Red valerian about to flower

In spring our steps are awash with bellflowers, and these attract so many bees that you can hear them buzzing all day, and they are very pretty. If you have any walls with holes in then these are perfect to fill the gaps.

I love these little flowers

I love these little flowers

My partner introduced me to cosmos; a plant he grew with a lot of success in Canada. Although we have tried for the past few years to grow them, we have never achieved the large bushes he did before. However, we have managed a few smaller plants and this year have decided to grow them in pots as the slugs just can’t seem to resist them. Neither can the bees, and if you keep deadheading them they will continue to produce flowers. When the are finished, allow a few to go to seed and collect them for next year.

This bee went from flower to flower.

This bee went from flower to flower.

When it comes to native plants, my favourites are red clover Trifolium pratense, greater birds-foot trefoil Lotus pedunculatus  and foxgloves digitalis pupurea. These are all great for pollinators and look fantastic too. For me, another important group of plants are native grasses. I leave a patch at the back of the garden to grow long for the grass-loving butterflies and by doing so, we have seen gatekeepers, meadow browns and ringlets this year. Finally, if you can provide ivy Hedra helix then the bees will be grateful of the late pollen supply, whilst the birds will be happy with the late supply of berries!

IMG_3647 1

Foxglove flowers are perfectly designed for pollinators

This is only a few of the plants we have to attract pollinators but some of my personal favourites. The RHS has done a much better job at coming up with a list of plants here. The key things to consider are to provide lots of nectar and pollen-rich plants which together, flower throughout the season offering this food supply as long as possible. Whether the plants are native or not is really up to you the gardener, as after all – it is your space too!

If you are unsure of whether the plants you are buying are good for pollinators – look for the RHS Perfect for Pollinators logo.

Ragwort – dispelling the myths

Ragwort – Senecio jacobaea is a contentious topic I’ve noticed recently. When ever a photo is posted for identification on different Facebook groups I am following, the comments show a big divide of opinion and the same myths are often used in arguing for its eradication.

For those of you who are unaware of this native plant from the asteraceae family , ragwort is often known for its toxicity to horses and cattle. Some people believe that its toxicity is to be feared and that just by touching it the plant can cause liver failure and so must be removed at all costs – and there has been plenty of media hype to continue this prejudice. However, whilst it is potentially harmful to horses, it also has plenty of benefits to wildlife.

I want to write this because when we moved in last year and the garden was overgrown, there were quite a few ragwort plants in flower around the garden and my first instinct was to go around and pull it all up. I’m glad I didn’t and that I looked into it a little bit, because I later discovered a plant with a few caterpillars of the day-flying cinnabar moth Tyria jacobaeae happily munching away at the leaves. These beautifully distinct larvae with their stripy bodies rely on ragwort as a food plant and without it these critters can not complete their life cycle. Because of the control of ragwort a decline in the numbers of cinnabar moths has been noticed.

Ragwort is also an excellent nectar source for pollinators; bees, butterflies and hoverflies in particular. We had gatekeepers Pyronia tithonus visiting our plants last year which was a new butterfly for me and very exciting. Ragwort is thought to be essential to at least 30 invertebrates, so it really is in my opinion much more of a friend than a foe. This year, I have also planted marsh ragwort Senecio aquaticus around my pond because of how great it is for invertebrates.

2014-07-18 13.33.56

Ragwort control is only really necessary if it occurs in or around a field which is producing hay. This is because ragwort is harmful to horses and they are unable to detect the dried ragwort in hay and the toxicity of the plant remains. Ingestion of dried ragwort can lead to liver failure which is understandably a very good reason to avoid it – although how dangerous it really is is debated given the difficulty in identifying ragwort poisoning as a cause of death. It is also perhaps a good idea to remove it from any grazing paddocks ‘just in case’ even though horses tend to avoid it when it is fresh. We remove it at work when the sheep graze just as a precaution, although I’ve noticed a few plants after they have arrived and the sheep have seemed to avoid them too. It is also worth noting that there is no legislation requiring the removal of ragwort as is often believed. If ragwort is causing a problem then there are powers for an order for removal to be made through the Weeds act 1959, but an order has to be made for this to be enforced.

Ragwort will not harm humans unless perhaps you eat a lot of it. I’ve pulled it up with my bare hands many times with no adverse effects. There is of course the chance that you may be more sensitive to it and for every ten people who are okay with it, there will be one who developed a rash I’m sure.

If you would like to find out more about the truth of ragwort then there is lots of information about it on the internet such as here, here and here. In the meantime, if you find any growing in your garden let it grow and keep an eye out for the cinnabar moth!

“Tyria jacobaeae-04 (xndr)” by Svdmolen – Own work. Licensed under CC BY 2.5 via Wikimedia Commons