I'm doing a 35' x 1' x 1' long redwood planter box that is going to be mounted on top of a shed in full sun. We have the plants (libertia 'peregrin', zonal geranium 'vancover centennial' and coprosma 'evening glow') , some Gardener and Bloom potting mix (forest humus, peat moss, rice hulls, chicken manure, bat guano, kelp etc.) and one section of the box built. I have a couple questions. The life of this planting only needs to be 2-3 years then we will probably take it down. I'm trying to screen the roof of the shed until we can get some vines covering it.
1) Should I drill lots of holes in the bottom of the box and cover with screen to prevent the soil from falling out?
2) Should I do anything to try to prevent rot in the box? Someone suggested rocks in the bottom to prevent rot but after reading in the container forum this sounds like a bad idea even if its to protect the bottom of the box from having to much moisture on it all the time.
3) Should I line the box with plastic (with holes in the bottom of coarse) to prevent it from drying out to quickly. I haven't had to much luck with redwood planter boxes in the past.( I think they have some kind of allopathic chemical in them at this point!)
4) Should I add other components to the potting soil I've purchased to improve drainage? what should they be? i also have some left over 'planting mix' which appears to be made of similar ingredients but with bigger chunks of wood chips or bark i guess.
5) Can I have a soil that has good drainage but retains moisture well also. Sort of stays evenly moist but doesn't get soggy in the bottom? or is this physically impossible.
6) what material can i use for a wick.
thx container folks!
advice on long redwood windowbox, soil, plastic liner?
Holy Smokers that is HUGE and will be heavy when wet. I have cedar window boxes under all my window. I have stained all of them, inside & out. I would put a 1/2" drain hole every foot. I would line the box with landscape fabric to prevent loosing the soil.
I use Premier ProMix BX for all my containers and window boxes. I add smart-cote slowrelease fertilizer at the time of planting. Also, I put a layer of long sphagnum moss or mini cedar nuggets as mulch and it makes a huge difference for holding moisture.
What type of plant material are you planning on? I love petunias (wave) in window boxes, since deadheading can be tricky up high.
Here's a thought. Why not omit the bottom completely and construct the box in such a way that the sides act as a "sleeve", so to speak, and then slip a plastic container into it. Make your sleeve wider at the top and narrower at the bottom so the container won't fall out the bottom. You'll get the look or redwood without the need to worry about bottom rot. At that point all you have to worry about is using a good growing media; you'll find plenty of posts here discussing container media which discuss water retention while enhancing proper drainage. As to helping you retain moisture throughout your media, (while feeding your plants at the same time) I can give you a recommendation.
Cools ideas. The planter box is going to be in three sections. it will be looked down upon just slightly. maybe using it as a decorative container would be good if i can cover the top with something (moss maybe?) so that it can still look as if it was planted. do you think moisture regulation will be more or less difficult with all the plants in one to three gallon plastic pots?