Q&A for How to Build a Wooden Planter Box

If the box is on the ground, you can lay a layer of cardboard on the bottom before adding soil.

In the example given in this article, the author is using 12 foot long boards.

There is no reason why not. I am building 4 planter boxes to put in an area between fences and the whole area is rocky. I am not putting bottoms on them because once they are filled with dirt, the rocks should provide good drainage.

You can purchase screen at Home Depot, Lowe's, Ace Hardware, etc. I prefer fiberglass screening, it seems to last longer, and I line my planters with landscape fabric.

Yes, but consider adding 'feet' to elevate the box off the grass or soil, or it will rot.

If you use 12-inch-wide boards (1" x 12" x 8 ft.), the planter box will be 1 ft. deep by default.

Many sizes would work depending on the wood that you use. When working outside, deck screws are a great choice, probably 2 inch deck screws.

Cedar, redwood, and pressure-treated woods are all great choices. Cedar and redwood are both naturally resistant to insects and weathering. Pressure-treated wood uses chemicals to make it insect and weather resistant, so it may not be great for areas with children or pets. Cedar and redwood are safe for children and pets because they are natural, but they can also be more expensive than pressure-treated wood.

Drill holes every 6 inches for drainage, or use the cut end (boxed end) of the cedar to place them randomly.

3 X 3 boards are the best. You can even attach wheels to the bottom of them for mobility. But, when raising your planter off the ground, you will need to add thin strips of wood to the inside bottom of the box for support. The corners of the bottom board will have to be cut to accommodate the 3x3 legs. If you don't want the legs to be visible from the dirt surface, don't bring them up to then top of your box.

Just build a deeper box. It the roots do grow straight down and it's a narrow plant, you could probably get away with a narrower box, which would reduce the cost of the wood needed.

If it was purchased at a local lumber store, it is most likely 3/4".

I would say yes to the carrots and onions, but unless you go pretty deep with your planter box, potatoes might not fair too well.

Yes. As long as you put wood on the bottom and build it high enough off the ground so the plants can grow, you should be fine.

Plant tomato seeds in a planter box with some sort of support or trellis. Make sure the planter box gets plenty of sun. Water as needed and wait for them to grow.

Line the boxes with landscaping fabric to act as a weed barrier. Cut it about an inch larger the bottom of the box, fold it up the sides on the inside and staple it in place.

No, you shouldn't put the box on your roof unless you're certain your roof can take the weight of the box when it's soaking wet, and you have a guaranteed way of securing it.

Elmer's or any other brand of wood glue will work. Just note that this will make separating the boards difficult, should you ever decide to recycle your planter.

Figure out all the materials you will need from your plans or drawings. Then go online and shop for each item you will need from Lowe's, which will usually give you a price. You will not have to purchase the items online, but this will give you an idea how much your project will cost. When purchasing your boards, plan on using them right away. If you live in a drier climate your boards may start to warp, bend, or twist, unless you lay them flat on the dry ground/floor with something heavy on them. Don't let them get wet.

This wooden planter is for outside use. if you want to use something similar inside the house (which I wouldn't recommend, as the drier air will probably cause the wood to shrink), you'll need to get a plastic drainage saucer for it to sit on. Or alternatively, just use the planter as a holder and put pots with saucers inside it.

Approximately half an inch.

Using plastic sheeting would help the box to last longer. You'd have to make holes in the bottom over the drain holes in the box.

Yes, you can build or place it on almost any surface unless you're going to leave off the bottom piece. In that case you should place it on fertile soil.

Use the instructions above, except leave out the bottom, and reinforce each corner with a square wooden strip nailed or glued inside each corner. Place the box on the ground and fill it with potting soil or compost. Tamp down the box and its contents so they're in firm contact with the ground. Anchor the box if you can so it won't move.

Insulating the sides would not have much effect, especially in the winter. If Alberta spruce does well in your area, your sapling should be okay.

It depends on the fence. Most fences would probably struggle to support such a heavy item for a long time.

Use taller pieces for the sides.

Probably not. The box has drain holes.

Yes, that's a good idea.

Yes, this sounds like a suitable option. To prepare it, turn it over and drill holes, then proceed to use by following the preparation instructions above and planting.