Planting arrangement in a pot
By Bernard
Cambridgeshire,
United Kingdom 
My wife is keen to create a planting arrangement in a pot 13in diameter, perhaps with a feature evergreen in the middle, with smaller plants around and small plants around the edge to dangle down. She wants to avoid using plants with strong root growth so as to avoid overcrowding of the roots but no gardening books seem to deal with this aspect.
Do any members have any thoughts on the subject as suggestions will be very much appreciated.
7 May, 2009
Answers
Pansies and violas have shallow root growth, so may be suitable as an option.
There are lots of annuals that trail for the edges like lobelia or petunia. I have heard that lobelias have shallow root systems too.
There is no reason why you could not keep a conifer small, but you would have to read up on the bonsai books otherwise as Moon grower says, even the small ones grow bigger than you would think.
If you wanted to have the plants flourish from one year to the next you would have to feed them regularly once the nutrients in the new compost were used up and maybe add in new compost as well as trim the roots every couple of years or so.
7 May, 2009
Previous question
Hi Bernard, by 'evergreen' do you mean some type of conifer or other shrub? If so this will rapidly take over the pot and deplete the compost. You might find it better to use all bedding plants or a mix of perennials and bedding plants. I guess you could get away with a very small conifer but remember it will grow... We've turned fish boxes into troughs and these can look good planted up with slow growing plants - see David's blog http://www.growsonyou.com/bulbaholic/blog/3084-3-let-the-sun-shine
7 May, 2009