top of them might help speed up their growth. they do well when directly sown outdoors, just need to make sure the soil temperature is warm enough for them. one of the things we have to watch out for in our garden, is those tender, tasty little plants get gobbled up in one bite by snails and slugs. the whole plant disappears! so be sure to bait or prevent snails from eating your little plant before it even has a chance.
there you go! now i only know all this because i learned from my experience. so if you have found that something works for you, please share, it might help 