Hi gurus,please kindly help me to analysis these three keywords.

Type the follwing keywords in Google, the approx search results:

weed control fabric: 1.4 million
weed mat: 0.4 million
ground cover fabric:5.6 million

Analysis them by Google keyword planner, found the follwing:

weed control fabric: monthly searches 4400, competition 1
weed mat: monthly searches 2900, competition 0.82
ground cover fabric:monthly searches 390, competition 1

If choose one of them as main keywords of my website, which one is the best?

Are the results of google keyword planner only for google adwards? I don't know very well, who can help me? Thanks in advance.