I have five big concrete pots with soil in them. Some have wild greenery of some kind and the others have moss. Should I just till the soil and turn the surface over, or should I do something to remove the existing plants before transplanting flowers or herbs into these pots?

EDITS: (to answer Stormy's questions below)

These pots are concrete and I will not move or tip them. I could shovel out the existing soil if I were to replace it. I am open to any plant, preferably not expensive as I am a beginner and not ready to invest a lot. I was thinking flowers surrounded by herbs (sage, mint, parsley, basil and cilantro). The patio will have many days in a row in the summer of direct sunlight beating down with temperatures in the 90s F (30s C).

Picture of weeds in one pot Weeds in pot

Picture of moss in another pot Moss in pot

  • how wide and deep are these pots, in terms of inches?
    – Bamboo
    Commented Mar 2, 2017 at 19:08

3 Answers 3


Plants in pots need all the help they can get from us. That soil is critical. I would dump that stuff out, all of it and scrub the pots with bleach and water. It looks like someone used garden soil and that is the biggest no-no for container planting. Dump those pots out and clean the pots. They will be heavy but it is very doable.

Purchase a few large bags of cheapo sterilized potting soil and fill your pot with soil and plants leaving 1" from the surface to the rim. Pots this large should be planted with at least one 1-2 gallon plant. I am not sure how big these pots are. It would be better if you told us what plants you are planning to plant and send a picture of the entire group of pots. I was unable to pull up your second picture, sorry.

I used to plant huge pots and actually 'landscape' patios and decks for big bucks. Done correctly, your planted pots are very valuable and beautiful and worth purchasing potting soil. Do not get potting soil with water holding gels or sponges or even fertilizer. If the soil comes with mycorrhizae and bacteria, that is great. I always added that to the soil. Potting soil has very little soil included. Every single year that soil was changed for new. Trees would be the only exception and even then as the tree roots take up all the room in the pot, I'd tip those pots over, slip the pot off, root prune, add new soil.

If there are just herbaceous perennials and annuals, I always tipped the pot on its side and using a pruning saw cut out individual perennials leaving separated plants with plenty of roots and soil to be replanted after cleaning out the pot and old soil, replacing the potting soil.

Do not add any rock or pebbles or packing peanuts or gravel below the soil and above the drain hole. That creates a perched water table situation and ruins drainage ability. You'll probably find exactly what I described at the bottom of your pots. It was and still is a popular 'old fashion fix' that is very tough to change. Just soil and plants.

When you chose plants keep a few rules in mind. 1) You will get more 'punch' or beauty by using fewer species. 2) Tie your group of pots together by using the same or at least mostly the same plants for each pot. 3) The plants should all have similar needs; water, pH, shade, partial shade or sun. 4) Think of differing LEVELS; a tall tall plant, a shorter filler such as Orange sedge, floriferous annuals and of course a few trailing plants such as potato vines to flow over the sides. 5) Use Osmocote 14-14-14 extended release that you will only need to use once per season. 6) Don't be afraid to STUFF plants into your pot. I always lightly break up the root ball to encourage better root growth and sometimes I 'butterfly' root balls to fit a plant into a small space.

Water as you fill your pot with soil. This will help to firm and ensure no big air pockets. Once planted try to lift your pot. You will water shallowly and a bit more often at the beginning. As the roots grow into the lower reaches of the soil you will water less. Get used to the 'feel' of the weight of your pots. Just nudging and lifting a corner will give you a good 'feel' and soon you will know when to water by just a 'nudge'. Do not over water!

If you tell us what you are planning to plant, would like to plant we can discuss maintenance and pruning. Another vital rule for flowering plants is to get those flowers off as soon as possible. This will encourage a more vigorous and healthy parent plant that soon you will find it difficult to keep up with just the old flowers!

Send picture of your pots. Get rid of whatever is in those pots completely and clean with bleach and water. Who knows what was in that old soil! Let us know the environment you plan to place these pots, your zone or location in this world. I would also filter your city water source before using...cool if you are on a well. Oh! Get POT FEET to lift the bottoms of your pots off the surface they will sit. This increases drainage.one of my landscaped decks with water wall

  • 1
    Please note your questions are answered in edits to the question. Commented Mar 2, 2017 at 18:41
  • Thank you for the additional information. Still need to know how big these pots are. I am a very tiny little girl and learned how to move these big heavy concrete pots and make life easier by tipping them on their side. Physics is my friend, let me tell you!! Otherwise, shoveling the soil out is a fine solution. Then hosing and using bleach/water to clean before new soil is added. In my picture, you should be able to see the paver I used to raise the bottom of the pot off the surface. Where is it that you live? Herbs go well with tomatoes as the tall guy. Maidenhair grass?
    – stormy
    Commented Mar 3, 2017 at 1:32
  • Adding a tree or shrub will shade the rest of the plants. Or one pot having a tree next to the others will help cool/shade the others. Make a list of plants, don't be afraid to think outside your box! Big pots NEED big plants right now to suck up extra water. Tiny plants/tiny pots, medium sized plants larger pots etc. You could also plant vines... golden hops is spectacular and will perform all the necessary things large concrete pots dictate!! This is the fun part!
    – stormy
    Commented Mar 3, 2017 at 1:37

You need to remove whatever is growing in your pots by the roots, so take a hand fork, insert it into the soil and lever up the plants by their roots and lift them out. Remove as much moss as you can, then have a good dig around in all the pots to turn the soil over, preferably incorporating some slow release granular feed (in the UK, that would be Growmore with an NPK of 7-7-7, but depends where you are what you can find to use).

Have some new potting soil ready to mix in with what's there, because removing roots and moss will lower the level of available soil, then plant. The alternative is to turn the pots out, dispose of the contents, including the soil,and fill up the pots with brand new potting medium, then plant.


I would just till the soil with the moss and remove the top layer of the soil along with the plants of the pot with the "weeds".

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