After many years of urban gardening in all four garden types, in-ground beds, raised beds, box beds, and portable containers (small yards/ patios/decks/ roofs/balconies), I find a box bed is well worth the cost and effort if you have the space to dedicate to a box bed garden.

Box beds come in whatever size you choose to build, and the benefits are many:

  1. Long-lasting bed.
  2. Easily maintained as organic.
  3. No need to test ground soil for contaminants.
  4. Supports high density planting.
  5. Large amount of root room.
  6. Deep soil suitable for plant supports (e.g., spirals/cages/stakes/nets).
  7. Easy access from all sides and a height that saves your back and clothes.
  8. No need to till soil.
  9. Handy to your kitchen.
  10. Fewer diseases, harmful bugs, weeds, and critters (squirrels excepted!).
  11. Re-useable soil that needs amending only with compost or well composted farm animal manure each fall and mid season.
  12. Attractive look with cucumber/squash vines over the sides and flowers interplanted.

Winter is an excellent time to plan to build a box bed for the next season. The initial cost in time, labor, and money is fairly high, but well worth it as a box bed will serve you for many years at very little or no cost per year depending on your need for organic seeds, and compost or composted farm animal manure. Little additional cost if you save seeds and prepare your own organic compost.

Because this container is for the long term and the bed is not moveable, planning is very important. In the spring, site your bed for maximum sun exposure (6-8 hours of sun) and have one long side face south. Then check for the following:

  • Any necessary approvals (bylaws, management restrictions, residents’ association rules, city easement).
  • The box location for wind protection, ground gradient, drainage, and people traffic.
  • Engineering report on weight bearing if box bed is on a balcony or roof.
  • Access to the box for soil delivery, wheelbarrow traffic, water source, nearby composter, and for garden tending (Caution: wider than 4 feet poses reaching problems. Make the bed 4-ft. wide if 360-degree access, but 2 to 2.5-feet wide if access from only one side – i.e. box against a wall or fence).
  • Accessibility for wheelchair or walker if necessary.
    Note: a wheelchair gardener’s side reach is limited to about 1.5-feet. Telescoping tools are handy, but the gardener must be able to reach the individual plants.

NB — Since the box bed will be separate from the ground soil (i.e., no digging), locates for cable/electricity/gas/water/septic system are not essential unless you suspect that access to these underground features will be necessary in the future. Moving a box bed would be a serious challenge!

Next, decide on the size of the box bed. A standard box is usually 4ft x 8ft by 2ft deep.

However, I have seen boxes of all widths, lengths, and depths, but none shallower than 12 inches (30 centimetres). Smallest was 4ft. x4 ft. x 3 ft. and largest was 4ft.W, 16ft. L, x 3ft. High.

(Photo: these box beds of 4×4 posts do not need supports)

Internal supports & slight bow

(Photo: these 4 x 16 box beds of boards have internal supports that are weak and failing — sides begin to bow outwards)

Internal supports & slight bow

The box can be made from any wood except painted, treated, or reconstituted/glued wood. Spruce, Pine, and Fir (SPF) are inexpensive but do not last more than a few years (approximately 5 years). Eastern white cedar (see my box bed at the top of this article) and Hemlock (Brewer Park Community Garden uses hemlock) cost a little more and will last the longest (15-20 yrs.).

You can also make a 4’x8’x2ft. box out of cement patio stones set on their sides in a wood (DIY) or metal frame (Lee Valley).

A box can be made with boards or with 4”x4” posts either rough cut or dressed (dressed looks better and has fewer slivers and clothing grabbers, but costs a few more $).

A bed constructed of boards will need corner and side supports (usually metal corners and side supports of 2×4’s sharpened and driven into the ground) so that the boards do not bow out or separate and leak soil especially when the bed is watered. These supports should be on the outside of the box to brace the boards and have the wet soil pushes the boards outward against the supports. If the supports are on the inside, they rob you of garden space, they are annoyingly in the way when you cultivate the soil to remove old roots, the fasteners will eventually pull out of the damp 2×4’s, and the wet soil will push the boards out away from the supports so the boards are no longer attached – mine did!. The next rain or watering will carry soil out between the side boards. Years ago I made that mistake in the interests of good looks. I regretted it for all the reasons mentioned. I still see it today in a number of box beds in both Winnipeg and Ottawa.

Our box has 4” x 4” dressed/planed posts of eastern white cedar in a log cabin configuration, 5” galvanized spikes, a gravel drainage base, geotextile to sandwich the gravel, garden soil not potting soil (organic if possible but if not, ask about the composition of top soils as not all soils are equal – I used Big Yellow Bag and was very satisfied with the 4-part composition and the performance of the garden soil, but it is not certified organic although the owner of the franchise (Hamilton/Burlington area) assures me he has tried, compost (my own) or composted sheep manure (very effective – I use it often at sites where compost is not available), tarp (optional but recommended as a winter box cover to stop water leaching away the plant nutrients and to keep out snow impurities), and enough rope to tie down the cover.

Bottom fabric + medium Gravel

Top fabric

Finish building, filling as you go so lifting soil or dumping a wheelbarrow into the box is easier

List of purchases for our box bed 4 ft. W x 6 ft. L x 2 ft High.

  • Posts – (14) 4-inch x 4-inch x 6 ft. and (7) 4-inch x 4-inch x 8 ft.
    Note a standard box of 4 ft x 8ft x 2ft is actually easier to build: 21 posts of 4” x4” x8ft –
    – cut 7 of the posts in half for the ends of the box.
  • Galvanized 5” spikes at 10 spikes per level: 6 levels x12= 72 spikes.
  • Gravel (medium size) – 10 bags.
  • Geotextile/landscape fabric – roll.
  • Garden Soil – 2 Big Yellow Bags.
  • Compost (3 in. layer) not needed until the end of the first season.
  • Tarp at least 10 ft. x 10 ft. NB the tarp will fall into the bed and make a winter bathtub unless you cover the box under the tarp with slats. I use old metal panels from a canopy.
  • Rope (pass the rope through the grommets in the tarp and draw it tight)

Support-panels and anti-squirrel chicken wire

Winter Cover with support panels beneath against snow load and bath tubbing in the depression

I did my home planning in the winter, purchased the components and assembled the box bed in May, and had a very successful gardening season of sweet peppers, hot peppers, tomatoes, onions, beans, and flowers. And the performance continues each year!

Once you have experimented with the box bed, you can consider these next optional steps – add small side pots to the outside of the box for flowers to attract pollinators, or to grow invasive plants like mint, and purchase hoops and 6 mil clear plastic to convert your box bed to a temporary greenhouse, poly tunnel, or cold frame to lengthen the growing season in both spring and fall.

Side pots + flowers for pollinator

Greenhouse/poly tunnel

Nov. 2 the growing continues – germination has begun in center space

If you use boards instead of posts, place the side supports outside the container rather than inside. Corners can be fastened outside with metal brackets, metal corners or galvanized strapping.

Outside posts keep the box in its shape while inside posts which make the box look good on the outside eventually fail to hold the boards. European churches use flying buttresses to hold the walls in and Canadian skating rinks as well as many above ground pools use outside supports to counteract the pressure coming from the inside. Naturally rinks and pools do not want obstructions inside the space and I suggest that a gardener will not want them either — although it is not a critical issue for the gardener. However, the more nooks and crannies inside will provide more bug hideouts – earwigs, ants, and sow bugs love the tight spaces — and if there is blight or other disease in the box, removing all the problem soil is more difficult. Keep the interior of the box clear of obstructions.

A top plate is an option — I have worked with boxes that have top plates and nobody sits on them because the gardener is facing the wrong way. I am not fond of working sideways and I suspect that is true for others! My physiotherapist raises eyebrows at the hearing of it, and in addition, the reach is very limited. The advantages of a top plate are to mask the tops of the outside supports and provide a shelf to hold pots, seed packages, trugs, watering cans, etc.

4×8 box bed built with boards

May the next growing season – whatever your garden choice — give you much to smile about!