Hi,

I'm about to build a raised bed, 5m (16') long by 1.2m (4') wide and am just wondering if that is too wide?
i'll have access to both sides and am thinking of fitting in 4 rows of vegetable plants here.
will that be ok?

it will be a mix of peas, carrots, lettuce, radishes, tomatoes and short sunflowers.
the raised bed will also have a hoop tunnel on it covered with fiber cloth and will have a drip hose going along each row.
or would one drip hose between the rows be enough?

another question is that the 'raised' part is just going to be a 45x220 (2" x 9") frame just on top of the existing grass.
should i remove the grass first or keep it or keep AND put down a ground cloth?
please note that the grass layer is only about 10cm thick then there is a bunch of old coal underneath.
seems they had an old kolmila (charcoal kiln) right next to our house way back in the day and sadly, this is the only area we have to put the garden.

Thanks!

My zone is nothing like yours but I saw no other replies so I thought I would lend my thoughts. In regard to the grass, I would pull it up or at least disrupt the roots so it doesn't rob the new plantings of water or other nutrients.

If the size suits you and you have easy access to the center without stepping on plants or packing down the soil you should be ok.

I have raised beds and I just added the soil over the grass. When you have that much dirt over it, it tends to die. Mine are about 12 inches high/deep. I've found 4 feet across works well, especially if you have access to both sides. Make sure your hoops are high enough!

My husband and I built raised beds of landscape timbers held in place with BIG nails, or stakes slid down the holes we drilled in the corner sections and down the length. The height was about 2 ft, and the boxes were 4x4 ft, 8x4 ft and 12x4 ft. We took used 2L soda bottles and cut the tops of and put those standing in the bottom of the boxes. We had very sandy soil that wouldn't hold water for 10 minutes and the bottles helped to catch and hold water down in the ground to 1 ft line. The plants could then decide how damp they wanted their roots: either in the bottles or between the bottles. We then filled the box with soil appropriate for the food we were growing in each box. The advantage of several boxes is that you can create different soils for different plants.

When my father died, I got some of his books. He had one on square foot gardening. Broccoli, cabbages, cauliflowers, peppers, potatoes all require a 1x1 ft square for each plant. Carrots, parsnips, leeks and onions were 16 plants (4x4 rows in a sq ft) or 9 (3x3) per square foot. Watermelons, cantaloupes, etc needed nearly a 24x24 inch space on their own. If you put in a heavy trellis down the length of your 4x4 ft box at the one ft line from an edge, you are growing up and can get 2 seeds per 24 inch square: one on each side of the trellis (1 seed in 1 ft x 2 ft, the trellis in the middle there, and 1 seed on the other side. Our watermelons were whoppers so in my 4 sq ft box I planted a seed in each corner of the box (back about 6 inches) and let them sprawl over the edge of the raised bed. Green beans, black beans, peas, snow peas, etc. were planted with a string trellis down the center of 1 ft x 4 ft part of a box with 2 seeds ( one on each side of the trellis) and a total of 8 seeds per each foot square ( 3 in. spacing). Leaf lettuce, turnip, beets, head lettuce can be planted as 9 in a sq ft. You can also do herbs like this as well. If you harvest the outer leaves during the season, you can get 4 plants per sq ft.

This worked wonders for us and limited the space required for the garden, easy height for weeding, and easy to replant as your veggies came to harvest. We also sent any visiting kids out to the garden to get veggies for stir fries, stews, etc. They were so invested in the harvesting that they ate them all.

Enjoy!