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Rule of Thumb - Number of Plants Per Container

I’m laying out annual plants for each of my pots using the thriller-filler-spiller method.   In past years, I’ve planted fewer to allow for plant growth, but then they look sparse early-on.  I’ve also loaded pots with plants for immediate beauty, but them it seems many plants get overtaken/drowned out during the season, so it feels like a waste to have planted so many.  Is there a rule of thumb on how many plants to plant per pot size?   I have pots ranging from 7”-27”.  All annuals.   Appreciate your thoughts!  


  • Nanny BeachNanny Beach Posts: 8,717
    I always over crowd them, really difficult to say how many because it depends on what plants you are going to use
  • K67K67 Posts: 2,507
    When they do these on gardening programmes they stuff them in with no space at all but they always use well grown plants.
    Don't often do pots but  leave about 3 inches between plants and by midsummer they had filled the pot.
    Suppose it's best to space now  and keep them out of the way until looking fuller or use bigger plants for instant impact.
  • B3B3 Posts: 27,313
    If you overfill, you need to be careful that they don't go mouldy in the middle due to lack of airflow.
    In London. Keen but lazy.
  • ObelixxObelixx Posts: 30,009
    You really need to check eventual sizes.  Something like a lobelia will need far less space than a petunia or a railing fuchsia.  Do use the best compost you can find and feed regularly and never let the plants go thirsty and you'll have a full, healthy pot.
    Vendée - 20kms from Atlantic coast.
    "We don't stop playing because we grow old; we grow old because we stop playing." - George Bernard Shaw
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