By Taurman
Cork,
Ireland 
Additional Nasturtium Q?
Hi folks, have planted a difficult embankment with N this year which did well although it was boomer year for feasting slugs, I did not use a membrane but was diligent about keeping the grass cut to allow them to thrive. Q. Will the Nasturtiums overcome the grass in future years forming ground cover or am I destined to have to keep on top of the undergrowth? Thank you in advance.
4 Sep, 2016
Answers
Thanks Bamboo, I fear not, just the box standard one.
4 Sep, 2016
Unless what you've planted is Tropaeolum speciosum, which dies right back in winter anyway, nasturtiums are not perennial - they do seed themselves, but none of them, including T. speciosum, will make a dense ground cover sufficient to choke out grass. If you want a good dense ground cover such as Cotoneaster Queen of Carpets,, the grass should be removed prior to planting because its impossible to remove or cut as time goes on.
4 Sep, 2016