Topic: Gardening on clay soil - advice please

[sweet-pea]

Hi all,

I'm hoping that there are some of you that garden on clay soil. 

I am designing a garden for a friend as part of my Garden design course, and although I have many ideas already, there is one big problem.  Her garden is heavy clay that gets pretty waterlogged after rain especially in the winter.  The soil in slightly acidic, pH 5.5-6.5.

I'm recommending that she probably needs to get some kind of drainage system in place, and that she will need to improve the soil with grit, sand and organic matter.  But I'm struggling a little more when it comes to suggesting suitable plants to grow.

So I'd love any tips on what would grow well in similar conditions?

Many thanks

SP xx

[manicscousers]

if we're talking flowers, we just fill up a planting hole with good compost and plant in to it, or build up borders, we've got st john's wort, bluebells, ground cover, paeonies, honeysuckle, clematis, in pots, our soil is very heaavy clay, we've been trying to improve it for 34 years, still can't grow bulbs, unless in pots or raised walls, where we've raised the borders, we've now got some really nice shrubs 'n' stuff, and of course all our apples, plums, pears and hazel, they're not bothered, hope this helps  :D

[sweet-pea]

Thank you, that's great :-)  My friend planted loads of bulbs in the summer, but I have a funny feeling that none of them will come up, which will be a real pity after all the planting effort.  I like the idea of a hole filled with compost, and although I had thought of raised beds for her veg patch, you're mention of raised beds for planting ornamentals has just triggered the beginnings of a flash of inspiration :-)

Sp xx

[norfolklass]

my mum has clay soil (she's in hertfordshire) and whenever I've planted anything for her I always put plenty of leaf mould and plenty of compost in the planting hole, like manicscousers. despite it being like concrete (and having huge cracks in it every summer, 95% of stuff I've planted have done really well. I think as long as they get a good chance to get established (leafmould, compost and regular watering) the clay holds nutrients well. some of the plants in my mum's garden have gone bonkers!

I've planted:
clematis 'Bill Mackenzie'
jasmine 'Fiona Sunrise'
rudbeckia
echinacea
a couple of buddleias
fatsia japonica
spirea 'Bridal Wreath'
a couple of lavateras (since dug up as they got too big!)
ceratostigma
ceanothus
a couple of hebes
and a few other bits and pieces that I can't remember

so more shrubs than perennials, really. have to say that when I visit in the summer my mum's garden always looks lush and green and everything is healthy and blooming and I'm always slightly jealous! my garden has really light soil with no organic matter in it and in the summer it blows away like dust :(

[sweet-pea]

Wow, thanks Norfolklass, great to see Clematis, Jasmine, Rudbeckia and echinacea on the list as they are some of my favourites, I shall look up the others as I'm not so familiar with them.  It's good to hear that people are having success, it will give my friend a boost as she's feeling a little disheartened at the moment as she thinks most of what she planted in the summer has died.
I'm going to try and find info on what grows in such conditions in the wild too as that might provide some ideas too.

SP

[fluffygrue]

Our back garden has very heavy clay acidic soil. In winter I'm sure I could use it for making pottery, it gets so soggy. Things that work well here are.. Rhododendrons, camellia, roses, clematis, bamboo.. Heuchera does well as ground cover. Brunnera seems to love the moisture. Schizostylis too.. Things that are greedy will enjoy the soil. Bulb-wise, daffodils and crocuses seem to cope fine, but things like dutch irises and anemones don't manage. Have a Google for 'plants clay soil' and you'll find plenty of inspiration.

I wouldn't really see heavy clay as a disadvantage, more an opportunity to grow things that enjoy the soil. :)

(The only thing in the lists above that I can't seem to grow is echinacea. Dunno why!)

[Andy H]

I am surprised you mentioned bamboo? I thought that loved really light sandy soil?

Thought the roots loved to whizz along in easy ground?

I am probably wrong.... :-X

[kt.]

Brassicas which like firm planting do well. Make beds narrow so you dont have to walk on the soil. Digging it over in autumn  & letting winter weather get at it will help break it down. Dig in plenty of sharp sand , grit , and organic matter to incorporate air & improve drainage - This will turn into workable, good soil.

[norfolklass]

found some recent photos of my mum's garden. other things I've planted that have done well:

japanese anemones
alchemilla mollis
a stripy grass that I don't know the name of (lloks a bit like a spider plant)
phygelius 'African Queen' I think (but it's a REAL spreader: was in a 6" pot, is now 6' across and gets hacked back every year – beginning to regret planting it!)
a couple of heucheras
a couple of hellebores

[Blue Bird]

Hi Sweetpea
I have clay soil it is that bad that they make bricks from 3 miles away!!
I manage to grow passion flower / pryracantha (black birds love it) / daphe / camellia / hosta /clematis / japanese maple /Mountain Flax / primula / hardy gerianum (10 different ones they all love it)  Euphrbia / Arum Lily / Digitalis / crocosmia / Penstemon / jasminum / helleborus / solgnum

always put fish and bone meal in when plant out

we did put down a drain (used the large yellow pipe with little gaps in it on a bed of grit)

Add lots of compost and mulch really well as it needs to be kept moist or it will crack when dry .

Good luck
BB

[saddad]

Yep... good luck you'll need it but it does hold nutrients really well.... they can't wash away into the subsoil cos it is still full!
 ;D

[sweet-pea]

Thanks Blue bird, that's great.  It can be hard to tell sometimes when looking up plants, sometimes they will include that they grow on clay soil, and then they say require free-drainage...which to me leads to confusion!

[dandelion]

I'd add daylilies to the list. I wouldn't recommend Japanase maples if you soil is really havy.

[triffid]

Being on the edge of London, we have heavy clay soil now somewhat opened up in texture after years of leafmould and compost being dumped on it.

The following have always not just coped but really thrived in our garden -- even before we started trying to improve the soil.

Roses
Clematis
Hardy (species) fuchsia
Hebe
Magnolia (stellata) -- though several neighbours have wonderful large-flowered magnolias, too
Daffodils & narcissus
Cowslips
Hellebores
Japanese anemones
Box
Lavender (yes, I know it's supposed to like lighter soils but no one's told ours  ;D)
Columbine
Lily of the valley
Violets (everywhere  ::))
Lilies (longiflorum)
Victoria plum 
... and a Japanese maple which, like the lavender, doesn't seem to know any better!

Hope these additions to your ever-growing list are helpful (or cheering, at least!) -- by the way, before we started adding compost and stuff to our soil both our garden and our allotment suffered bad waterlogging in wet seasons. Nine years on, our garden never gets bad; four years on with the lottie and it's also much better. No drainage system as such; just loads of muck, raised beds where necessary, and no walking on the worked soil.

[fluffygrue]

Lavender (yes, I know it's supposed to like lighter soils but no one's told ours  ;D)
No drainage system as such; just loads of muck, raised beds where necessary, and no walking on the worked soil.

Same here with the lavender - I think with ours it's because it gets pretty dry and baked in summer. Only English lavender really thrives, though - French always keels over in winter.

Definitely agree about the no walking.. especially in winter. Having just planted two apple trees, I'm pretty much caked in mud. Not ideal for the planting, but it needed doing today.

[Barnowl]

With these winds coming up, don't forget to stake your trees. I didn't know you were meant to until a kind neighbour did one of mine for me because she was so worried about it!

[sweet-pea]

Hope these additions to your ever-growing list are helpful (or cheering, at least!) -- by the way, before we started adding compost and stuff to our soil both our garden and our allotment suffered bad waterlogging in wet seasons. Nine years on, our garden never gets bad; four years on with the lottie and it's also much better. No drainage system as such; just loads of muck, raised beds where necessary, and no walking on the worked soil.

Yes very, thanks.  Great to hear that you no longer have problems with waterlogging, my friend will be glad to hear that, I know at the moment she's quite disappointed in the garden.

[saddad]

My heaviest plot is at the bottom of the site (almost) one wet summer there were streams running through the rows of earthed up potatoes.. looked like a mock up for the Somme!
 ;D

[ACE]

With these winds coming up, don't forget to stake your trees. I didn't know you were meant to until a kind neighbour did one of mine for me because she was so worried about it!

The thought on staking has changed a bit recently


The stem diameter growth of a tree is stimulated when it sways in the wind. If a tree is left unstaked, the whole tree-including the stem-will sway, stimulating maximum diameter growth at or near the root collar. Over time, this swaying will help form a stout, firm tree with a stem that tapers evenly from base to crown. The unstaked tree will thus develop a structure which can flex under the force of wind or vandalism. As roots at the root collar also increase in diameter from the movement of the stem, the tree is given added stability.


It has also been found that stem diameter growth towards the base of the tree is increased by planting 'feathered' trees, rather than trees with clean pruned stems. If feathered trees are used, they can be pruned progressively over the following years, as necessary.

[Barnowl]

Makes sense - but do you start with stakes to prevent root rock, then loosen up the ties or not bother with stakes at all?