Perfect for balconies and small spaces, sack gardens have been used a lot in other countries, particularly in Africa — there is a lot our generation can learn from places like Africa, China and the Phillipines in terms of growing crops in small urban spaces here in the UK, where many people have forgotten WWII victory gardens and allotments are so few and far between.
We made our first sack garden on Saturday from one of the sacks that our yurt cafe’s firewood is delivered in — another way of reusing and recycling and reducing our imprint on the planet. The weather has been terrible. It hailed on Saturday. So we started inside, talking through what we were about to do:
What we started with:
- A sack
- A bag of sand and gravel, and a bucket of more gravel and pebbles
- Bags of potting compost
- A utility knife
- An old pallet to build a base (a saw and pencil were needed to cut this down to size)
- A larger pot with its base removed
- Strawberries in small pots and one thyme plant, which we divided. Seeds for peas, broad beans, and chilis which were planted in smaller pots to grow and be replanted in our sack.
We were following instructions cobbled together from a few different and very useful sources: sendacow.org.uk sells sack kits and donates them to schools, one from the international aid organisation Engineering for Change, and another I found on instructables.com (one of my very favourite sites for DIY projects of all kinds from homemade robots to garden planters). We were also helped by the invaluable experience of Carol, gardener extraordinaire whose practical experience made this so much easier than it might otherwise have been.
We started by making a raised base for it, from a pallet obtained by some friendly builders just across the road.
We put that where we wanted the sack to stay (one this size, or any size, is very heavy indeed) and leveled it off. It’s really best if the sacks are leaning against something or held upright by stakes. They’re heavy, but it’s rather devastating if they fall. We also put it somewhere where it will get lots of sun…beside our front door.
We filed the bottom with a mix of sand and gravel to ensure that it drains all right — plants need water but most of them hate being waterlogged. To ensure the best drainage, you need to build a column of gravel in the middle. How you ask? We will show you.
We had no coffee cans per the instructions, so we took an old pot and cut out the bottom of it (a coffee can, or any plastic container with straight sides would absolutely have worked better). Setting it in the middle of the sack, we filled it with gravel:
We then surrounded it with soil using a smaller pot
And tamped it down.
Carefully we raised the pot, leaving the gravel column intact
Then started the whole process again. We ran out of soil given the large size of the sack, but realised it was stable enough to begin planting anyway, which is a good thing to know.
Using the utility knife we cut a cross into the sack and scooped out some of the soil. We used the plant pots to make the right sized holes in the soil, so we wouldn’t disturb or crush the root balls of the things we were planting.
We repeated this process, testing out the alternate suggestion of making a T-shape as suggested by one of the instruction sheets, but it seemed to work the same either way. At Carol’s suggestion we separated the little pot of thyme and planted those into smaller holes — that’s where the gardening experience came in really handy.
It’s still quite early to plant outside and the weather has been frigid, so we were limited in what we could find at the nursery. But part of the day also involved sowing some seeds — peas, broad beans and chilis — that can be planted in our sack when they are ready.
Although some sites I read said that seeds could be sown directly into the sacks, most agreed that plants were better, as seeds were likely to wash down and away. So we shall wait, it is always wonderful to wait for seeds to sprout and to watch them grow. Meanwhile, we can’t wait for the thyme to grow big enough that passers-by can take some to flavour their cooking on their way home from the train (these are communal sacks, so we wanted to plant renewable crops that people can pick and pick and pick in small quantities). But mostly we shall be on the watch for strawberries…you can never ever have too many strawberries. These are alpine strawberries — suitable for the early planting, and they like particularly good drainage, so hopefully they will be happy just above the layer of sand!