Do I have to put rocks at the bottom of a pot/planter before adding the soil?

Question

Hi!
I am planting petunias and geraniums in round plastic pots with holes at the bottoms (for drainage).
So my question is do I have to put rocks down before adding the soil?
I normally do put the rocks down, and my flowers grow great, but I don't have rocks and was wondering if putting rocks is really necessary.
Thanks for reading and I hope you can help, have a great day.

Answer 1

As you say, rocks promote drainage, as soil tends to "compact" and if its "clay" it will not let the water drain properly.

Marbles or anything that gives "space" will work also.

I wish you well...

Jesse

Answer 2

It is a good practice to line the bottom of a pot with rocks or broken pieces of pottery to improve drainage, but you can do other things like using a light soil mix (adding sand, perlite, etc) so that the soil doesn't hold as much moisture. You can use a slightly smaller pot than you would have for the size plant. Just keep an eye on how rapidly (or not) the soil dries out and make sure you don't overwater.

Answer 3

The short answer is no you don't. The principle behind chucking a few stones in the bottom of the pot is to keep the pot more aerated,and to stop the soil being too compacted. but modern potting mediums, though still based on the traditional John Inness composts, are generally much lighter, easier to handle. In the old days it was put a few crocks of a broken pot over the hole before you added the compost.

Now I've recently potted up a plant, and I chucked in a few stones I picked up from here and there simply to add weight to the pot. I don't want it blowing about here and there.

Get some hints from your local gardening centre. The chances are they haven't added rocks to the bottom of the pot for ages. But I'd love to be proved wrong.

Answer 4

The rocks add a little space for water to drain away from the soil and roots. And they help keep the soil from coming out of the drain hole bit by bit when you water your plants.
If you have an old clay pot that you don't mind breaking up, you can do that and add the shards to the bottom of the pot.
The rocks in the pot are not absolutely req'd - but they will aid drainage a bit and help deter root-rot if you over-water and aid drainage for 'happier' plants, and they do help keep soil in. ... (I have a Bachelor's in Horticulture, herbaceous plants -and I have planted without any buffer at the bottom of the pot a few times.)

Answer 5

You don't have to. The rocks help drainage, but are not totally necessary so long as you have holes at the bottom.
I put rocks, broken pots, Styrofoam chunks, etc whatever i have around to fill up the bottom a few inches so I don't have to spend alot on potting soil. I don't add any if my pots aren't big - 12' dia or smaller.

Answer 6

I usually put rocks in also but in some I didn't (got lazy looking for some) and I don't see any difference. Rocks just help the drainage a little won't effect the growing of the plants if you use good potting soil like miricle grow.

Answer 7

All the other answers are good but if you don't add a some of the weed landscaping cloth to prevent the soil from going around the rocks then you are defeating the purpose. Don't forget to break off the older flowers on the geranium to promote more budding.

Answer 8

Putting rocks in the pot only helps if you have no drainage holes, It prevents "root rot". It sounds like it will be unnecessary.

Answer 9

It's not necessary, but it does help for drainage. Another good idea, which involves recycling, is breaking up dried corn-cobs and placing them in there. They decompose, which adds nutrients to the soil and they provide sufficient drainage.

Answer 10

Turns out they don't actually assist drainage http://www.abc.net.au/science/articles/2014/02/10/3937778.htm but that doesn't rule out the benefits of keeping in your soil...