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Grit for potting up bulbs

Next week I'm going to plant tulips and other bulbs in pots and in the ground and aim to heed the advice to give them good drainage.  We're on thin chalk and flint soiI. 
In the past I've bought bulb-planting compost but didn't get great results.... It was light and fibrous but didn't appear to be very free-draining... No sign of sand or gritty particles. I have a big pile of gritty sand left over from laying paving and making a concrete screed base for a shed and greenhouse.  I think it's sharp sand.
Is that OK to shovel into the bottom of the planting holes and to fill the pots, along with ordinary garden soil and  the used compost from my tomato pots?




  • Lizzie27Lizzie27 SomersetPosts: 9,617
    It's not usually recommended because of perceived impurities in the building quality stuff whereas Horticultural sand/grit is washed free, especially of lime content. Having said that, you could always thoroughly wash yours through with a hose (if you don't mind the mess) and use some for your bulb pots.  Others might well disagree though.
  • FairygirlFairygirl west central ScotlandPosts: 47,119
    I wouldn't put it at the bottom - I'd mix it with the other stuff you're putting in. It can often just create a sump :)
    Just make sure it's clean. Sand is often full of salt etc.

    Make sure it's gritty too - the stuff used for concrete and mortar has the opposite effect, as it binds together, so it may not be suitable at all. 
    It's a place where beautiful isn't enough of a word....

  • Pete.8Pete.8 Billericay, EssexPosts: 9,040
    Yes, as Fg says builders sand is usually soft sand, and sometimes has additives.
    Knowledge is knowing that a tomato is a fruit.
    Wisdom is not putting it in a fruit salad.
  • Thanks, all. Think we've had enough rain to save me needing to hose it off!
  • FireFire North LondonPosts: 15,454
    edited October 2020
    "I think it's sharp sand.Is that OK to shovel into the bottom of the planting holes."

    I would have thought that if you are planting into chalk, you shouldn't have a problem with drainage and wouldn't need grit. Chalk is about as free draining as you can get.

  • FairygirlFairygirl west central ScotlandPosts: 47,119
    I think it was for the pots @Fire :)
    I find pea gravel does a decent job if you don't want to buy grit. It's bigger, but mixed in, it suits well enough. 
    It's a place where beautiful isn't enough of a word....

  • celcius_kkwcelcius_kkw Posts: 732
    edited October 2020
    I absolutely adore perlite as a grit/sand substitute.. it’s light weight and very easy to work with.. personally the lightweight feature works great for me, there’s nothing more backbreaking than trying to repot a plant or pulling out annuals from a large grit filled pot that’s sooo bloody heavy! 
  • I feel silly asking this, (but here goes anyway 😂).. a parcel was delivered containing a lot of foam "noodles" to fill the space between the product and the box.. has anyone used them in pots as a Perlite substitute?  I think I'll try it, assuming they're fairly inert. 
  • FairygirlFairygirl west central ScotlandPosts: 47,119
    Perlite is perfect , but it could be pricey if you have a lot of pots to fill  :)
    I've often used chunks of polystyrene in the base of large pots, to save filling the entire thing @purpletreacle. I usually put a layer of cardboard or similar over it to prevent soil/compost draining through. When emptying them, bits break off, or have broken down, and I often think they could be useful for drainage.
    When it's only for ornamentals, I can't see it being a problem, but they might be a bit big?
    It's a place where beautiful isn't enough of a word....

  • JennyJJennyJ DoncasterPosts: 6,608
    I'd certainly use them to fill the bottom part of deep pots for shallow rooting plants (with some card/newspaper/j-cloth/pieces of old t-shirt or somesuch to stop the compost washing through, like @Fairygirl says), but they might not look so good mixed in, unless you can break them up into perlite-sized bits. Personally I don't even like the look of white perlite bits in compost, but that's just my preference.
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