For years I had a vegetable garden in a space some distance from the house. What with one thing and another, I stopped planting. Now more time than I'd like to consider has elapsed since I used the space, and I'm looking to start up again (the last couple of years I've used a small space near the house, but it's a bit crowded and sun is limited).
So, I'm looking to reclaim the space, with some complications. By far the biggest two are:
-- it's become overgrown. Not filled with brambles and brush, but adjacent lawn has grown to cover the area; the grass has been kept mown.
-- I leave near the bay on Long Island, NY, and coastal flooding has become more of an issue than it used to be. The place I've been growing the last couple of years is above all but major (hurricane) flooding but the old garden certainly is not. That's an issue for maybe a few times a year, but it's certainly an issue. I don't know what the salt content of the existing soil is.
So my basic solution is raised beds. But not just the typical 6 inch frame filled with dirt, but something higher. I'm not anticipating flooding, but I can't dismiss the possibility.
My two considerations:
1) do I rent a tiller? Or put plastic mulch over the grass and put the beds on top? Or use a spade to skim off the grass and build on that, with or without the plastic? (I figured that if I'm building higher than usual, room for the veggie's roots are less of an issue.)
2) what the heck do I build this out of? From what I've read cinder blocks are not advisable because of fly ash content. Then I considered retaining wall blocks, but realized that they're not stone but formed concrete, and may have the same issues. Untreated timber likely won't last long.
The space I was originally going to do was 10x12. But because of the scale of the raise, I'm going to drop that to 8x10 (why that size will be clearer below).
Home Depot has 4"x4" x 8' cedar; that would mean 9 pieces to get two levels, rather lower than I'd wanted (and just 3.625 actual). That's about $171 of lumber, before tax. But I was considering the complication of access to the plants... unless I wanted to (and could) climb up onto the raised bed, two 4x10 spaces would give me better accessibility, with a walk through in between. That would mean 14 pieces of cedar, and I'm up to $266, pretax, and lower height than I'd have wanted.
Then I thought, if I used concrete blocks, they're 16 in. x 8 in. x 6 in., so for the double planter I'd need 44 per level, 88 altogether to get to a full foot of height. At $1.50 each that's $132.
If I lined the insides with heavy plastic, there won't be an ash leeching issue (I'd only have to worry about BPA and phthalates and the like. sigh).
That would bring me to a full foot in height. I'd already planned to have 4 yards of topsoil delivered (for other things around the property as well, not just for this snowballing project) so that would bring me within 2" of the top... and I have quite a bit of garden soil (from the current beds) to supplement.
OK, long post, and I could go on... but any thoughts so far?