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Hydrangea petiolaris - does this need deep soil?

I am thinking of planting against my house wall but the soil isn't that deep (approx. 150mm) due to house foundations/rubble which I guess is typical for that situation. Since hydrangea petiolaris is widely recommended for growing against house wall does it follow that deep soil is not a requirement?

Thanks in advance for any experience you can share.

Comments (7)

  1. Grower


    I have found that position is key to this plant Mike. Mine didn't like full sun, west facing but is happy in the shade east facing. It recovered well from my planting mistake so if you have no other options in mind give it a shot and keep an eye on it though 15cm of soil isn't much, so if you can dig out any rubble it will help. I lost 2 clematis in a position like yours and am now trying jasmine, having dug out deeper and wider to improve the planting site. Good luck!

  2. Grower

    Mike Davis

    Thank you for your comments Linda. The position seems tailor made: north facing, shade to dappled shade, that's really why I bought the plant.
    I was concerned about the soil but It's only in a 9cm pot so may establish easier in shallow soil and find it's own way.
    However, your comments re your own experiences make me think I should try to improve soil but it wont be easy as its also next to a path. I'll give it a go the plant only cost £1.77 so wouldn't be a costly failure :) Thanks again

  3. Grower


    These are great in shady or semi-shady positions such as the one you describe, but bear in mind that they can grow very tall - over 5 metres high in the right conditions is not unusual, and vines of this size will generally have a very extensive root system. I'd say if there's plenty of space for the roots to grow laterally then it should be ok in shallow ground, otherwise you may want to dig out as Linda suggested.

  4. Grower

    Mike Davis

    Yes, thanks for this Nick, and I do hope to grow to a reasonable size so I will try to improve the area as best I can before planting.

  5. Grower

    Rachel the Gardener

    As an alternative, you could build a raised bed which could double the depth of soil available: build it with a gap of a couple of inches away from the house wall, to avoid damp issues, and build it as long (sideways to the house wall) as you could reasonably make it. It would keep the path cleaner by not having soil spilling onto the path. If the path is narrow and the bed is fairly wide, you could set the raised bed back a couple of inches, with shingle around the base, which would in effect widen the path slightly. The slight loss of bed width would be made up for by the depth of soil inside the raised bed.

    You could even knock the bottom out of a trough or large pot, sit that on the earth and plant into it.

    In both these suggestions, the Hydrangea roots will fill the pot/bed then find their way down into the soil, thus benefitting from being part of the larger soil bank (earthworm activity, microbes, access to water bank etc) while also having a lot more decent soil to help them get established.

  6. Grower

    Jim Edwards

    Be wary of raising bed that this does not cover your damp course against the house.
    You should plant the root ball 2ft (600mm) away from the wall this should avoid the foundations.
    All climbers like to have their roots shaded, use a good mulch and cover with bark , gravel or stone/slate chippings.
    Excavate at least twice size of rootball and refill with multi purpose compost mixed with sharp sand 4:1 or use a perlite based such as Durstons available from any Spar shop.
    Good luck

  7. Grower

    Mike Davis

    Thank you all for taking the time to share your thoughts on this. Some really useful ideas & advice.

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