5 resilient flowers that will thrive in the most difficult summers

Resilient flowers are an essential part of a successful garden.

However carefully you choose the right plants for your weather, soil or zone, there’ll always be the unexpected weather event. Here in South East England, we usually have quite dry weather in the summer.

But in 2021, we had double the normal summer rainfall. And it was also cool and windy. Flowers were blown about, or were late to emerge.

And this summer, 2022, is one of the driest on record, with a record-breaking heat wave. (If you’re having a dry summer, here is some expert advice on how to save your plants.)

So the stars of the show have been the most resilient flowers and plants.

 

I’ve identified five resilient flowers I personally have found both tough and beautiful. Then I checked out what many major horticultural associations and plant sellers had to say about them.

So these five flowering plants will withstand both dry and wet weather, a range of soils and are also hardy across a wide range of zones or climates. They’re also a little less fussy about sun and partial shade than many other flowering plants.

Plus -at the end of this post, I’ve added a couple of good performers in my garden which may suit you.  But these last two will come with a hazard warning. So don’t plant them until you’ve checked them out for where you live.

5 resilient flowers for your garden (+ 2 warnings!)

Find out more about each flowering plant and whether it will suit your garden in the post below.

1. Oakleaf hydrangeas (Hydrangea quercifolia)
2. Cosmos (Cosmos bipinnatus)
3. Catmint (Nepeta)
4. Globe thistle (Echinops ritro)
5. Roses – there’ll be one for you

The two plants I should warn you about are Bear’s britches (Acanthus mollis) and Japanese anemones (Anemone x hybrida). They are beautiful and can work in your garden. But they can spread too vigorously. And they are also forbidden in some parts of the world.

All seven of these plants were chosen in the wet, cool summer of 2021. In the ultra-dry, hot summer of 2022, they have also been good performers in my garden. I particularly commend roses for carrying on flowering whatever the conditions.

Oakleaf hydrangeas – the most easy-going hydrangeas

Eleven years ago I planted an oakleaf hydrangea (Hydrangea quercifolia ‘Snow Queen’) under a tree and beside a wall. It is a very difficult place. Most other plants I’ve put there haven’t survived.

And in the autumn, it has beautiful rich red foliage.

Although hydrangeas are reasonably resilient plants, most need watering in a prolonged heatwave. But I have never watered my oakleaf hydrangea. Some years I even forget to prune it. So it has survived total neglect.

Most hydrangeas prefer partial shade, but the oakleaf hydrangea can handle full sun, too. The RHS says it can be planted in North, South, East or West facing positions. And it can cope with exposed or sheltered positions.

It’s also widely quoted as being rabbit and deer resistant. But, as Rosy Hardy of Hardy’s Cottage Garden Plants explains in Perennials Made Simple, all plants can get eaten by a deer or a rabbit sometimes.

Oakleaf hydrangeas come from the United States, where they’re hardy between Zones 5-9. So they’ll survive UK, most European and Australian winters.

Note from the ultra-dry summer of 2022: I haven’t had to water my established Hydrangea quercifolia yet, and it is looking good. However two new Hydrangea quercifolias, planted this year, are not yet established and are suffering badly from the weather. Any shrub or tree will need some extra watering in its first summer, especially if it’s hot and dry.

Cosmos – one of the most resilient flowers for a border

I’ve grown cosmos (Cosmos bipinnatus) almost every year. It always come up trumps, whatever the weather.

Keep dead-heading cosmos throughout the summer in order to enjoy flowers until the first frosts. Otherwise I have never personally either fertilised or watered it, even in the driest summers.

Cosmos is an annual, so although it’s considered hardy in a very wide range of areas, it doesn’t survive the winter. You plant new seed again every spring. However, Sarah Raven also suggests planting cosmos seeds under cover in September if you have a greenhouse or potting shed.

Cosmos prefers full sun. I’ve grown it on the edge of one of my East-facing borders, but it strained to reach the light and never looked fully happy. And when I checked the RHS, BBC Gardeners World, Sarah Raven and US gardening blogs, The Spruce and Gardening KnowHow, they all confirmed this.

However, they all varied their advice on soil. Some said cosmos must have dry, poor soil. Our soil is dry, but quite rich. So I would interpret that as ‘cosmos is pretty happy on most soils.’

Cosmos is loved by pollinators. And although it self-seeds, it isn’t considered too aggressive in the UK, Northern Europe or Australia. But there are a few places in the US where it’s on an ‘invasive plants’ list.

Note from the ultra-dry summer of 2022: the cosmos flowers are smaller than usual in the very dry weather. But they are still carrying on!

Catmint/Nepeta – even less fussy than lavender

A friend recommended I grow catmint (specifically Nepeta ‘Six Hills Giant’) because it is less fussy than lavender. And lavender is not considered fussy – although it hates damp soils.

There are several different varieties of nepeta. It has grey-green foliage and spikes of blue, white or pink flowers. I’ve grown the taller one, ‘Six Hills Giant’, in both borders and pots. I’ve found it indestructible.  The flowers can last from June to September. If they over, chop them back and you’ll get a second flush. Otherwise you never have to feed or water it, or certainly I never have.

Nepeta is loved by wildlife, and is ‘rabbit resistant’, according to plant grower Claire Austin of Clare Austin Hardy Plants. So it’s less likely to be eaten than some of your other plants.

A friend of mine was dividing nepeta. She dropped a clump off for me in my front garden. I forgot about it. The next time I looked, it had taken root. So you barely need even to plant it.

There is some debate about whether nepeta is a suitable companion for roses. Several sites recommend it. But well known rosarian Michael Marriott of David Austin Roses told me it was not a good choice as it’s quite vigorous. Roses hate too much competition for nutrients.

Many sites also recommend growing nepeta in full sun. But my nepeta has been fine in full sun and partial shade, and I’ve come across others who agree.

When I come across contradictory information on lots of different sites, I assume that this means different people have different experiences. So I’d recommend at least trying nepeta in partial shade. For more about choosing plants for shade, see this post.

Globe thistle – loved by pollinators

I’ve got two clumps of globe thistle (Echinops ritro ) in my garden. Both flourish whatever the weather. This is a member of the thistle family. Thistles are labelled ‘invasive’ (and therefore sometimes illegal) in some parts of the world.

However Echinops ritro seems to be accepted as non-invasive in every one of the dozen national and international blogs and websites I checked. It even has an Award of Garden Merit from the RHS. But check it out where you live before planting it.

I was, however, puzzled to find that everyone said it grows to 2ft-4ft. Mine is taller than I am (5’5″). It’s a remarkable presence in the garden. The white variety of echinops grows up to 6ft, but mine is definitely not white. Mine is blue. It is adored by pollinators.

There were also mixed messages over whether it must grow in full sun. One of mine is in full sun. The other is in an East-facing border, where I have had trouble growing sun-loving plants in the past. Both are towering and healthy.

So, once again, I’d suggest giving it a go and seeing what happens.

Note from the ultra-dry summer of 2022: This blue globe thistle has performed beautifully in my garden in both the dry and wet summers.

Roses – there’ll be one for you!

I really thought carefully before including roses as ‘resilient flowers’. So many rose varieties ‘ball’ when it rains (the buds and flowers turn into mildewy balls and don’t open properly.) Roses also need dead-heading and how many flowers you get depends on whether you feed them.

But some are incredibly resilient. They really are. And there’s a rose variety for whichever impossible situation you find yourself in. My sister-in-law lives in Vermont, with four months snow a year. She has a catalogue of Sub Zero Roses.

And two of my roses have bloomed happily through wet summers and super-dry ones. One is ‘Bonica’ and I’ve lost the name of the other. It looks like Eustacia Vye, which was bred by David Austin for its ‘Wet, Windy & Exposed’ list. Both tolerate full sun and partial shade and grow on a wide range of soils. They flower from mid-summer to late autumn, if dead-headed regularly.

Rosa rugosa, the wild rose, is also very resilient. But it is on the UK’s Schedule 9 of the Wildlife & Countryside Act. That means it is considered invasive, especially in coastal areas. It is an offence to grow it in the wild or allow it to grow in the wild. As it’s quite difficult to prevent plants from escaping from your garden, this means that a responsible gardener will think twice about planting it.

It’s still sold, however, by many reputable companies and organisations. I checked six leading plant information/sales websites. All sold Rosa rugosa. None mentioned the issue of Schedule 9. So it’s down to us as gardeners to decide whether to include invasive plants in our gardens.

Note from the ultra-dry summer of 2022: The roses in my garden have performed extremely well, in spite of almost no rain for 7 weeks. We fertilised them in spring, and this has increased their resilience. Good rose fertilisers include Vitax Organic Rose Fertiliser and RHS Empathy After Plant Rose Food. (Note that links to Amazon are affiliate, see disclosure.)

Thugs – flowers that are just too resilient!

Any plant that grows well in many situations has the potential to grow out of control in some places.

For us, as gardeners, it is merely irritating when a plant takes over our borders and refuses to be dug up.

But if plants go rogue in the wild, they often out-compete plants that usually grow there. Insects, algae, mosses and other organisms that rely on the indigenous plants can die out. Then the species that rely on those organisms can struggle. And the chain goes on.

So, in many parts of the world, there has been an effort to identify garden plants that may damage the wider environment. The UK has Schedule 9, as I mentioned earlier. Apart from botanists getting cross on Twitter, I’ve never seen anyone take any notice of it. Though I would be delighted if you could contradict me.

In the US, Canada and Australia, bans on invasive species of plants are taken much more seriously. So check which plants are considered just a bit too friendly where you are.

But there are less vigorous varieties…

In the UK, Acanthus mollis (Bear’s britches) is not listed under Schedule 9. But it is a spreader. Once you have it in your garden, it is extremely difficult to dig it up again.

But it has a wonderful sculptural shape, and withstands anything the weather can throw at it.

I have a less invasive variety called Acanthus mollis ‘Rue Ledan’, available from Sarah Raven. It has pure white spikes instead of purple tinted ones. It’s adored by pollinators. I’ve had it for over seven years and it hasn’t spread too far. Although it is time to divide the clumps.

Note from the ultra-dry summer of 2022: Acanthus mollis ‘Rue Ledan’ has struggled a little. It is still a good presence in the garden, but I have had to water it once.

Japanese anemone – the prettiest of thugs

I hesitated whether to recommend Japanese anemone (Anemone hupehensis/ Anemone x hybrida) because once you have it in your garden, it’s very difficult to get rid of.

However, it is very pretty and fuss-free. So I went online to see what anyone else had to say. The first site said that Japanese anemones ‘thrive in shade and cope with dry soil.’ Very much my experience!  Three lines later, the same post told me I must plant Japanese anemones in ‘moist soil.’

Well, my Japanese anemones are in a dry, shady border, which I never water. We have around 26″ of rain a year, which is considered a ‘dry’ climate.

I trawled the websites of other horticultural organisations and plant sellers. Some said that Japanese anemones liked moist soil. Others that it needed well-drained soil. However, all agreed that once established, this is an exceptionally easy plant to grow.

There seems to be universal agreement that Japanese anemones won’t like very wet or boggy soil, especially in a cold winter.

‘September Charm’ has an RHS Award of Garden Merit and a ‘good for pollinators’ badge. However, other sites said that Japanese anemones have very little pollen so they’re not good for pollinators. I’ve just seen two bees hard at work on my pink Japanese anemones.

One site even said it was ‘rabbit resistant.’ Ha, ha….well, it’s worth a try…

Note from the ultra-dry summer of 2022: The Japanese anemone flowers in my garden have emerged and are pretty, but they are a little smaller.

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