I recently visited an herb & flower farm, and the growers had lots of perennials, annuals and herbs in greenhouses, and they had to water these plants all day long, twice a day for some plants, just to keep them alive. The greenhouses were swelteringly hot and humid, and the water that fell between the plants or ran out of the containers just sank through the gravel back into the ground, which is good, considering they had to dig 3 wells on their property just to supply enough water for their plants.

I came home to my back deck's "garden," where I had baby perennials growing in plastic drinking cups (the disposable kind you see at parties), with one tiny nail-hole in the bottoms for drainage, stacked on shelves in open air (partly shaded). My plants looked quite happy and healthy without a greenhouse or twice-daily watering.

My question for professionals is this: what's the advantage of using pots with lots of big drainage holes? It seems to me that the water would run down the edges and right out the bottom without saturating the root ball. My plastic cups each have a single small nail-hole poked in the bottom, so they hold the water longer, long enough for the capillary action to reach all parts of the soil, then dribble the excess water slowly through the single drainage hole. So sometimes I don't even have to water every day! Why isn't this more commonly done? Does it actually promote fungus or disease, or does it compact the soil too much? I haven't had either problem yet, but I've only been doing this for a little while.

Also, what's the advantage of growing perennials in summertime under a greenhouse? My plants are growing up in the air temperatures and weather conditions that they will be living in once they're in the ground, instead of in a greenhouse.

Thanks all!

Regards,

Tara.