How many drainage holes in planter?

Latimer

Hi all

I have these large metal planters, approx 1m x 1m x 0.5m high which have these two 15-20mm holes in the bottom for drainage (the red thing comes out). Is that sufficient or should I be drilling more in? I've tried with the drill bits I have but the metal is too strong so if I need more holes in going to need to get some special bits.

I'll be filling the bottom with polystyrene I have lying around.



Sorry for the pics being out of order, I'm on my phone 🙈

JennyJ

Is it watertight other than the two holes? I'm wondering whether there'll be some draining where the joint is, around the edges, as well. Maybe you could try putting a bucketful of water in and seeing how long it takes to drain before forking out for new drill bits.

Latimer

JennyJ said:

Is it watertight other than the two holes? I'm wondering whether there'll be some draining where the joint is, around the edges, as well. Maybe you could try putting a bucketful of water in and seeing how long it takes to drain before forking out for new drill bits.

That's a good idea! How quickly should it drain?? 

JennyJ

Just water, fairly quickly I would think. As lond as it does drain away I think it'll be OK though. You don't want them to have water sitting in the bottom for a prolonged period of time if you get persistent heavy rain, particularly in winter when plants are likely to be dormant.  You won't be moving those babies under cover once they're full.

Latimer

Ok, so these things are designed stupidly. The bottom is flush with the floor so basically the holes are always blocked! I've raised it off the floor slightly and it drains away fairly quickly do I don't think I'd worry about it being waterlogged. 

Also @JennyJ, you were right, the joints let out a ton of water

JennyJ

No need for extra holes then 😊. It's always a good idea to raise pots/planters off the ground a bit so that the holes don't block. You'll need something strong for those. I'd use something like several bricks each - each corner, half way along each side and maybe a couple under the middle - don`t want the bottoms falling out.

Latimer

Thanks @JennyJ