whats the best plant

It all depends what the rules of the cemetery are whether you can grow plants or not. If you can I'd go for low growing easy maintenance shrubs.

You also have to be careful as - if the maintenance men don't mow your plants to ground level the bunnies sure will!! Heathers and tiny bulbs might be rabbit- proof but little else is....but plastic! Perish the thought - but some of us ARE reduced to such measures.Headstones with a vase are best - then if the cemetery rules don't allow planting - you can at least have some colour all year round.

I agree with what Moon grower said, and would suggest one of the low Hebe's such as "Nicola's Blush"growing to 75cm x 75cm and bears pink fluffy flowers profusely. It is hardy and won't need watering . It does like full sun and well drained soil.

I asked a gardener at the cemetery where my parents are buried what flowers he would recommend. He said polyanthus in the winter and geraniums in the summer. He reckoned they were the least maintenance and always gave colour and could take dry conditions.

Guess it depends whether Katie wants to plant something and that is it or have to go to the grave twice a year or more to do the planting. If the cemetery is close that wouldn't be a problem... but if it is hundreds of miles away.

If it is in full sun and dryish soil try Sedum, various kinds .

If in shade Vinca minor .Soleirolia or Ophiopogon (Mondo Grass) all for permanent planting.

We have successfully planted various small Sempervivums on a friend's grave which have filled up a nice space and are at ground level.