New site: beginning new research

The new research bed

In January 2021, we moved house (and plant nursery) from East Hanney (Hanney), near Wantage, Oxfordshire to Maypole, near Monmouth, south-east Wales. We traded 6 acres semi-improved grazing land for 20 of ancient unimproved pastures, woodlands and seasonal streams and ponds.

Having completed 6 years of formal research in Hanney to quantify which garden plants attracted the most bees, I realised that the new site provided an opportunity to test several unanswered questions, the primary one being:

1, How much would the results for the plants tested in Hanney differ, if the same plants were grown in different conditions (soil, climate)?

But also:

2, How do garden borders compare with meadows for attracting/supporting bees?

With this in mind, we created a new research bed in May 2021 and planted it with many of the most bee-popular plants from our Hanney research. Of course, I couldn’t resist adding a few new ones too. As before, each plant has been allocated a square meter of border.

In spring of 2022 enough of plants had reached maturity ie. sufficiently filled its’ area to make data collection viable.  Not all plants had grown enough to be included but will be added in later years.

 

Local habitat context

The wider habitat context of the new site is quite different. In Hanney we were on the edge of a village but surrounded by arable fields with hedges and field-margins. There were some trees but mostly a field boundaries. The whole area was relatively flat, Thames Valley, on heavy clay. In Maypole, the site is part of the more rolling Monnow Valley where the agriculture is a mix of grazing, some arable and regular patches of woodland, mainly on the steeper slopes. In our own 20 acres, a quarter is mixed deciduous woodland and the rest is ancient, florally rich, pasture.


Climate and soil differences

In short (and no big surprise) it traditionally rains more in Wales. 660mm are the historical averages in Hanney v. 840mm in Maypole, giving a 27% increase. Other aspects of weather are quite similar but in Maypole is slightly milder with less temperature extremes. The soil is slightly acid at 5.5ph and silt/clay rather than the neutral heavy blue clay in Hanney.


Findings from first year in Maypole

2022 saw a very dry winter followed by hot dry summer. I realise that most of you lived through this too, but for the purposes of this research it is worth documenting our local rainfall as I am certain it had an impact on bee/plant interactions.

As I write this, in mid-December, we have only had 538mm of rain this year, far short of the annual norms. Of this, almost a third fell in November which was too late to help plants or bees. The total rainfall up to October was almost 40% less than normal and every month from March to October experienced a rainfall deficit. This technically constitutes ‘long-term drought’.

As rainfall has a direct relationship with plant health and nectar production, the drought probably had more impact on the plant-bee interactions than any of the changes between Hanney and Maypole. Therefore I am loath to draw many conclusions yet and will need further years of data.

Having said that, the following observations that are likely to remain constant.

Differences in ‘plant happiness’:

·      Some of the plants which prefer an alkali soil are not as vigorous, notably Teucrium hircanicum and perhaps Veronica spicata.

·      Some plants that struggled to cope in the very heavy Thames Valley clay are doing much better in the softer silt. These include Agastache foeniculum - which I had to replace most years in Hanney - made it through the first winter in good health. Geranium magnificum is also much happier here; in 2017 the RSPB asked people to tell them which garden plants they thought attracted the most bees and Geranium magnificum came out top. At the time I challenged this and still think it’s a rather simplistic result but, having struggled to get this old-fashioned geranium thrive in Hanney, this year it shot up our ranking.

 

Different bees

  • There are some distinct changes to the range of bee species I have been able to identify, so far.

o   We still have all the common bumblebees and most of the cuckoo bumblebees but now we also have a few of the much rarer brown-banded carders.

o   There are significant differences in the range of solitary bees. For instance we don’t have any wool carder bees (even on our nice big patch of Lambs ears). However we have the relatively rare long-horned bees. Very exciting!

The main difference in the bee species is probably due to the presence of our 8 acres of ancient meadow which has a very high proportion of broad-leaved plants but is dominated by birdsfoot trefoil followed by knapweed. This is a much richer source of wild nectar and pollen than our previous environment.

  • Although the average number of bees in the research bed seem to remained very similar, the mix has changed with a much higher proportion of solitary bees and fewer honey bees

o   The solitary bees are dominated by masses of lasioglossums – particularly smeathmanellums.

The L. smeathmanellums live in a large aggregation, of several thousand, in the old south-facing stone walls of our house, only 3m from the research bed. The bare silty soil between the plants in the research bed itself also seem to offer good housing opportunities for many other species of small ground-nesting bee.

We still keep a couple of honey bees hives but they probably have a much wider range of local forage in our meadow as well as local hedges and trees. This may account for fewer of them coming to the research bed.

 

Top performers Maypole 2022

The plants that attracted the most bees in Maypole in 2022 (a year of drought) had considerable overlap with those from the 6 years in Hanney.

Most of the biggest changes seemed to be due to the drought with the more Mediterranean plants such as Calamintha nepeta, Origanums, Lavandulas, etc, all doing well. Nepeta mussinii also shot into the top set for the first time since 2014;  it just kept flowering and attracting pollinators right through the heat and lasted for a total of 22 weeks.

The surprise for me was that Geranium ‘rozanne’ did not cope with the drought and stopped flowering around mid-August where it would normally keep going into September. Both Geraniums pheaum and ‘magnificum’ did very well but are May-time flowerers and so managed to perform before the drought really hit.

Based on such limited data it’s not appropriate to publish more but I am committed to do continue for a further 2 years which should provide robust data to answer the question outlined at the beginning of this report.

Many thanks

Rosi


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