On 30 Mar, 16:16, tellisg wrote:
Hi All,

I am a novice at gardening - I recently moved into my new house and
since most of the front garden was paved over, I have just built some
very large planters using decking boards that were left over from a
patio decking project. I plan to grow hedging, topiary and other plants
in it. I actually need two bits of advice.

1) The deckboards are untreated. What is an easy way to protect the
inside of the planter from rot due to the damp soil? Should I line with
with plastic liner or is there any way I can "treat" it? As there are 8
planter, each 2.4 meters long, I am look for the easiest solution.

I would be very surprised if the wood sold for decking was untreated
(except where you cut them, of course). Regardless of what you put
inside them I'd give them a good coat of one of Mr Cuprinols'
preservatives to extend their life.

ormally you'd have a plastic liner ( a large tub of sorts) and cut the
boards to box it in to suit - tub first, woodwork second if you see
what I mean. It's quite normal to make a lip around the top to
obscure the top edge of the liner. I dont doubt you could make a soft
liner inside with some sort of imperiable sheeting, but the weight of
that much soil/compost would certainly test your woodworking skills
and design!

Don't forget that the tub inside will need drainage holes at the
bottom to avoid waterlogging, and those will need covering with crocks
and large stones to avold the soil blocking them.

As to filling them I'll leave others to comemnt apart from saying that
peat substitutes are to be preferred on ecological grounds.