Star Border Performers and Strugglers in the Heatwave

Nollie

Just for general interest really (and a reminder to self!)

Some of us in Europe recently had a pretty severe heatwave compared to the UK (peaked at 45degC here) but it still sounded pretty hot back there too. For me, there were some surprising stars and strugglers, allegedly ‘drought tolerant’ or otherwise... plus differences in the same plant but different cultivars. Here’s my list, all in full sun unless otherwise stated...

Stars - sailed through uncrisped:
Berberis Atropurpureum
Nandina Domestica
Cotinus Royal Purple (part shade)
Lagerstroemia Purely Purple (part shade)
Chaenomeles unknown upright white and a sprawly red
Abelia Grandiflora
Floribunda Rose - Julia Child, Wild Rover, Iceberg, Sevillana La Perle 
Dahlia - all types
Agastache - Black Knight, Blue Boa, Totally Tangerine, Tango
Salvia - Caradonna, Greggii (red), Guarantica Black and Bloom
Echinacea - orange and pink unknown varieties, Magnus Superior
Kniphofia - Uvaria, Wrexham Buttercup (latter not flowering yet)
Euphorbia - Mellifera, Coralloides, Polychroma Bonfire, Blackbird
Crocosmia - Lucifer, Emily Mckensie (latter not flowering yet)
Helenium - Moerheim Beauty, Waltraut
Penstemon Raven (new young plants not flowering yet)
Dicleptera Suberecta
Phlomis, yellow variety
Perovskia
Nepeta
Clematis Warsaw Nike (afternoon shade)
L x Intermedia (dutch lavender)

So-Sos - Went a little crispy or withered but mostly recovering:
Berberis Red and Orange Rocket - crispy ends
Sedum Jose Aubergine - a bit wilted and lost some colour
Salvia Amistad - wilted, some crispy ends, flowers died
Salvia Mainacht - as above
Verbena Bonariensis - foliage a bit withered, some flowers browned
Achillea Safran - foliage slightly withered at the base, a little colour-bleached
Gaura Whirling Butterflies - wilted, flowers died, sprung back again (part shade)

Strugglers - may or may not pull through:
Nandina Gulf Stream and Firepower - totally bleached out and desiccated 
Lorapetalum Black Pearl - purple leaves turned very brown and crispy, flowers shrivelled
Teucrium Fruiticans - pretty crispy for a silver-leaved shrub
Roses - DA’s - dislike my conditions anyway, blooms crisped, curled, bleached, turned pink
Sedum Purple Emperor - flopped to the ground, totally bleached out and sickly
Echinacea White Swan - foliage very dead, but in south-facing rockery/oven situation
Verbena Bonariensis Lollipop - definitely dead, same location as above
Magnolia Stellata, can’t remember which, total foliage death (morning sun, sheltered spot)
Geranium Rozanne - two totally desiccated, one in shade survived better
English/French Lavender - potted ones no longer with us

Anything surprising that starred or struggled in the recent heat in your garden? 

B3

The only thing that looks really good in the sunny part of my garden is the gazania and fuchsia magellanica. Most other things are looking hot and bothered but will survive if this doesn't go on too long.
The shadier side is looking lush though.

UpNorth

fascinating.  really useful     @Nollie what type of soil are we talking about, fairly dry and sandy?

Obelixx

That's odd Nollie.  44C official peak round here and yet my gauras in a hot, sunny bed have sailed thru as have the Maltese Cross and lychnis plants in that bed.   Helianthemu Lemon Queen looking OK but phlox, hardy geranius, dwarf pinks and perennial cornflowers not so good.   

All the established shrubs around the place have done well but a buddleia I plante in partial shade is drooping and needs a daily drink.  I shall move it in autumn.   The recently planted shade bed has proved too dry so I've rescued a hydrangea paniculata into a pot for TLC and need to move Japanese anemones and some hardy geraniums and pulmonarias.  Even leathery leaved bergenias aren't happy there at the mo.

My nursery of plants still in pots needs watering daily and my Japanese maples display on the northfacing terrace was blasted by storm Miguel and has some crispy, battered foliage as a result despite being sheltered from direct sunlight and given much TLC after the storm.

Nollie

Ah Gazanias, pretty tough plants!

UpNorth, I garden in a mountain climate on hard, rocky alkaline clay, on part volcanic rock, part limestone sierras, with very hard well water that comes straight from a source up on the sierra. The soil is well improved with loads of organic matter and grit, mulched thickly with ericaceous compost.

Did you get the hideous hot wind that was like someone blasting a hairdryer in your face, Obelixx? That probably did for many on my struggler’s list, more than the temps, maybe. The Gaura has perked right up again tho and is beginning to re-flower. Good to know about the lychnis, I had been eying up a red one...

Obelixx

Yes Nollie.  That didn't help either - Miguel made us really cold and then the hot blast finished off a lot of the upper foliage on my poor acer and a couple of other younger shrubs.  The well established ones seem OK.  Obviously have their roots down very deep.

I have several lychnis with the usual silver grey foliage - pink, white and blush white flowered forms and all doing well as is the green lychnis calcedonica with orange/scarlet flowers.  Brought those as babies from seed gathered in my Belgian garden so definitely good do-ers. 

floralies

We were lucky that we had some days of very hefty rain before the heatwave, which must have helped a lot of the plants. we have clay soil here which retained quite a bit of moisture. There are plants that struggle even in a "normal" summer - Salvia Amistead only tolerates dappled shade here while all the Gregii types seem to have fared quite well. Roses are all ok but the lighter ones like Charles Darwin lose their colour quickly in the sun.

Nollie

That was lucky Floralies, we had a huge thunderstorm and heavy downpour a couple of days ago, when it was 38, so pretty humid now. Oh and now it’s 40 again, so there is still a tail end of the heatwave hanging about.

Obelixx

Not here.  34C yesterday.  High 20s today and trying to rain, but failing.

Fire

Only 26oC in London and that feeling boiling enough for me. It's interesting that some of the sedums were struggling. I imagine a fair bit of the struggle is shock. Perhaps if 45oC came gradually and annually they might adapt better and cope. How is the wildlife coping? Any notable trends? I guess water loss is the biggie.

Hostafan1

Heatwave? what heatwave?