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gravel drainage

deswalshdeswalsh Posts: 43
I'm wondering when planting bulbs and tubers outside that require good drainage,if the grit should be added above or below the bulb?


  • hogweedhogweed Posts: 4,053
    Below for me, although I only do it for lilies.
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  • punkdocpunkdoc Posts: 13,726
    Perceived wisdom is that you should sit the bulbs on a layer of gravel.
    I do have some issues with this advice though, as I think if you sit a layer of gravel on top of poorly draining clay, you will still be sitting the bulb in a potential pool.
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  • Arthur1Arthur1 Posts: 538
    If you sit the bulb on a bed of grit then you know it is not sitting on or in water.  However it wont improve the drainage of the soil itself, for that you would need to add sharp sand.  Be careful not to create a sump!
  • deswalshdeswalsh Posts: 43
    On reading these two posts,it would not seem beneficial to add any gravel.
  • StevedaylillyStevedaylilly Posts: 1,087
    Hi Deswalsh  
    I would ensure you throughly dig up the soil to about 12 inch depth and add loads of compost as well as grit to the soil. Bulbs prefer well broken up soil and this will insure better drainage for your plants imo  
  • deswalshdeswalsh Posts: 43
    Thanks to all who commented.
    Greenfingers Steve mentioned compost,am i right in thinking that all or the majority of compost should be added above bulbs/tubers?
  • StevedaylillyStevedaylilly Posts: 1,087
    edited April 2018
    If you dig in compost based on the condition of your existing soil to a good depth,  the compost will be completely surrounding the bulb or tuber. The main factor is good drained soil for the roots so they don't become waterlogged and that could be difficult dependent on what soil you have
  • deswalshdeswalsh Posts: 43
    I have clay soil which i gather is not ideal for drainage.

  • StevedaylillyStevedaylilly Posts: 1,087
    It's not the best but I have the same and you can bet 60% to 70% who read or comment on this blog have clay.
    its a case of digging in manure and grit to eventually make you soil workable so that any plant that needs a drained soil to survive will. Manure will improve your soil structure due to earthworms and other insects that will be more attracted to improved soil structure.
    This introduction of insects in your soil will improves natural drainage 
    With your bulbs and tubers you can do pocket planting which means you dig and improve only the area that plants is going in, but in the long term you need to improve your clay soil or decide to buy only plants that will suit your soil condition.
  • deswalshdeswalsh Posts: 43
    Many thanks Steve,that's certainly very helpful.
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