Hedging – Plants with Feet of Clay

It is all hedging at this time of year….

These yew hedge planting pointers apply equally to almost all other hedging plants as well, certainly anything that needs a well drained soil.

  1. You can dig a trench to plant your hedging if the ground is well drained.
  2. You can improve the soil as much as you like if the ground is well drained.
  3. You should water your plants well and often if the ground is well drained.
  4. You can use the largest plants you can afford if the ground is well drained.

You have spotted a pattern here: when planting a hedge, it is important to think about drainage.

If you have heavy clay soil (sticky grey, blue or yellow), the good news is that you have richly fertile soil.
The bad news is that water does not drain well through it, which some plants have a problem with.

So please, save yourself a lot of hard work and a load of grief.  Watch our film on how to plant a country hedge (link on the home page) even if you are planting the smartest yew.

  1. On badly drained soils, always plant small plants.
  2. On badly drained soils, always plant in a slit, not a trench.
  3. On badly drained soils, improve the soil after planting and when your hedging is growing away by adding a mulch of well rotted compost/manure and letting the worms do the work.
  4. On badly drained soils, only water newly planted hedging if there is a danger that the soil will dry out completely. When you do water, soak the plants and then DO NOT WATER for a couple of weeks afterwards.

The reason is this:
If you dig a hole or trench in clay, it fills with water when it rains and the surface puddle water on the surrounding ground tries to run into your hole, keeping it full.
The fact that you backfilled the hole with lovely, porous compost when planting only gives it the consistency of a sponge in a bath.  The roots of almost all hedging plants need to be able to breathe underground.
A trench in clay means they will probably drown.

So plant hedging on clay the easy way and dig as little as possible!

By Ashridge Support

Ashridge Nurseries has been in the business of delivering plants since 1949.

15 comments

  1. Holly Nairn says:

    Brilliant advice on your website. I planted a yew hedge last year in a manured trench on clay and have watched it bronze and suffer – we have since put in more drainage, will add a foliar feed this spring and have our fingers crossed. I watched that very same programme last year and shook my head in disbelief at the presenter’s poor planting advice. I am about to plant a few more hedges on heavy clay soil and will do it your way, planting into slits adding rootgrow to the roots as I go, and mulching after. Look forward to better results this time. Only wish I had found your website sooner. Please continue your wonderful website – it is so very much appreciated. From fans in Central Scotland.

    1. Edward says:

      Hi Holly and a big hello to Central Scotland!

      To be fair on that presenter, it is perfectly good advice if your soil is well drained. Considering how many British gardeners have heavy clay, though….

      Back to your hedge: yew often bronzes after transplanting, so that shouldn’t be an issue, but a foliar feed will only work on green leaves.

      You might consider replanting – from now until early March is fine, on a day when the soil isn’t frozen.
      I can’t really judge without seeing it, but if you can see that it’s just too wet in the trench, then putting the clay back now is the best choice.

      As for future hedges, a plastic mulch sheet is worth a look – it becomes hidden in a couple of years and does an amazing job of keeping out the weeds & preserving moisture in summer with no work.

      You can tip the mycorrhizae into a bucket of water & dunk the roots in it immediately before planting. Pour out any excess on to the soil around the new hedge.

      Have fun!

  2. Hello all,

    I have just read this article . . halfway through digging a 49 foot trench in heavy clay – by hand!!

    The trench unearthed about 20% building rubble.

    Please can I have advice on what I should do?

    Put the soil back? Put the rubble back? Stamp it all down and cut slits?

    Advice gratefully received.

    I am ordering the plants this week . . .

    Chris

    1. Edward says:

      Hi Chris,

      Well, you are in a great position to do an experiment!

      I would pull out big bits of rubble and put it all the rest back in, churning in some well rotted manure if you have the energy (this will be good if there is quite a bit of rubble to remove).

  3. Katrina says:

    Hi,

    I am about to plant at 60 meter hedgerow in clay soil picked full of Cotswold Limestone and old tree roots. Given the length of the hedgerow (I am looking to plant Laurel) and stones etc ( took hubby and myself to dig a hole 250mm x 300mm for planting half a day in the same location)is there a better way than digging by hand?
    Any advise gratefully received

    1. Edward says:

      Hi Katrina,

      There are all sorts of small & large rotovators for hire, you can even hire a tractor sized version. Much faster than slogging by hand.
      My question would be, do you really need to?

      With heavy clay, it’s best to make one slit in the soil per plant with a spade, sweep a bareroot plant roots in and firm it all closed.
      Don’t bother making a great big trench and changing the soil. Keep the clay. If you do rotovate, just mix in some well rotted compost/manure as you go over it at the end.

      If the stones are really bad, then yes, you probably should rotovate – if you can’t stick a spade into it, you can’t plant in it!

      Cherry laurel would not be my first choice for alkaline clay soil, portugal laurel would be better suited and holly will really thrive on it.

      Good luck!

      Ed

  4. Katrina says:

    Thank you so much for your help! we have tried spades pick axes and even our own hands to dig in our ground there are so many stones – and large ones at that ! so rotivator it is. Thank you for your advise regarding species, we have already planted a lot of holly and so will take a look at the portugal laurel now.

    Thanks again
    Katrina

    1. Edward says:

      If the ground is that bad, I recommend hiring a pro to do it. They will have a bigger, badder rotovator than the ones you can get in a hire shop, and will use it expertly. It will be more expensive, but you could get someone to do in a few hours, whereas you might need to hire the machine for a few days to do a good job.

      The best hand tool is probably the azada shaped mattock, which is much lighter than a pick axe and better for moving soil around. Wet the soil well the day before you dig to make it softer. Good luck!

  5. Penny says:

    Hi
    I have behind a small retaining wall 3ft deep x 1.5 ft wide clay soil with gravel on top for decoration. The total length is approx 30ft and want to plant hedging – probably Laurel of some kind. Would it be easier to have troughs built and inserted into the clay then soil then plant the Laurel.
    Any info would be appreciated 🙂

    1. julian says:

      If it is real “potter’s clay” the laurel will struggle to establish and troughs would be best. If is is just heavy soil then plant straight into the ground.

  6. Caroline says:

    I planted a yew hedge three years ago and keep loosing plants in two areas of the hedge. It appears that we have blue clay! I love the well established part of the hedge and would love to have the whole hedge yew but do not want to waste more money on filling the gaps if yew will not grow there.
    Any advise will be gratefully received, even a suggestion of what shrub to put in the six foot gaps if I have to give up on the yew.

    1. julian says:

      Yew hedging plants do not like clay – you are right. It is not so much the clay actually as the bad drainage. As you have seen, once yew plants are established in clay, they grow away really well. As a last resort, I would be inclined to plant barerooted yew hedge plants instead of potgrown or rootballed ones. Plant small plants, do NOT dig or improve the soil. Instead, plant them down the back of a spade. Watch our video on Planting Country Hedging to see how this is done. They will suffer less from bad drainage this way and once established will catch the other yew plants up quite quickly.

      Good luck

  7. Clara says:

    Hi Julian

    I have bare root yew (20/30 cm bare root) that I tried planting down the back of the spade as you advised in clay/heavy soil. However, some of the bare root yew have such large and long root systems, some roots as long as 60 cm that I don’t quite know how to plant them.

    Do I trim the roots so that they are more manageable at about 30 cm long?

    Do I just try to jam all the roots behind the back of the spade?

    Any advice given would be greatly appreciated.

    Thank you.

    1. root says:

      Yew in heavy ground…. thanks for your email. The first comment is to make sure that you have clayey soil. If you have good drainage you can dig holes and plant in those. However if you are on clay then you need to follow the principles involved in planting down the back of a spade…

      1. Under no circumstances trim the roots unless they are damaged. They are a food store and help the plant into growth in the spring.
      2. The point about slit planting is that when the slit is closed up there is no hole full of porous spoil that will form a sump and cause the roots to sit in water all winter (which is bad for them). So if the roots are too big for a slit, I would be inclined to remove a whole “clod”, plant the yew against one side of the hole you have created, and then fit the clod back into the hole and firm it down.

      You will get the same effect that way.

      Good luck
      Julian

    2. Max says:

      Yeah, I had the same problem with slit planting on clay as suggested in the video… due to the size of the bare roots of the Yew hedging supplied.

      Difficult to take out clods, because I was planting through cuts in the agricultural membrane as suggested in the video.

      In retrospect I felt I should have purchased your ‘smallest’ size bare root Yew plants, rather than the medium sized, as their smaller root systems would have been more practical to plant down the back of a spade slit trench.

      All a bit of an experiment, 40 plants put in rather wet clay ground mid December (the rain has been horrendous recently) and we’ll see how they do.

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