How to Grow Organic Vegetables in the Worst Soil in Giant GrowSacks

What’s a good way to grow vegetables organically in a plot that’s just a bog? Is it even possible? This was the true quandary of a lady who lived in County Mayo, Ireland. Half her vegetable garden was water-sodden for most of the year.

She had read about such water-tolerant plants as… lovage, angelica, celery, water chestnuts, rhubarb, water caltrop, comfrey, water convolvulus, jerusalem artichokes (sunchokes), spirulina and water cress. But only gnomes will flourish in a peaty acidic bog. Not even water cress will.

Giant GrowSacks: the ideal way to grow more organic vegetables in damp soil

So here’s a simple way to turn even the worst boggy or acidic soil into a sustainable organic garden. Get hold of a giant rubble bag, the kind that contractors dump on building sites. Or a large plastic animal feed or cement bag. Fill them with a mix of aged manure, topsoil and grit.

Make several large holes in one side and roll the bags over so the holes rest on your boggy ground. Then the plant roots can reach the damp soil beneath. Plant several small pre-germinated potatoes in that sack.

Potatoes are a good first choice because, of all edible plants, they produce the maximum nourishment from a limited space.

As they develop, the potatoes can root down into the acidic boggy soil for water, and their tubers – shielded from light – will expand throughout the bag. And the haulm will grow out gratefully from the flaps.

One rubble bag will feed half the county

A small cement or manure bag will not give you a large crop. But one builders’ rubble bag should feed half the county. And potatoes need mildly acidic conditions anyway, lest they get scab.

You can use the same GrowSack approach for other vegetables and fruit that like moisture, like squash and tomatoes, if you have no choice but to grow food above bad soil. You can raise plants, by this method, even at the base of leylandii and other conifers which have turned the soil beneath their branches into a dark sterile wasteland.

If you choose soft fruit like strawberries that prefer shade and fairly acid conditions you’ll find they do very well in shallow GrowSacks beneath conifers.

At worst, if you have no giant durable sacks, you can use common plastic garbage bags. They’ll decay into fragments by fall. But this is no matter because then, in any case, you should tip the bag contents on the ground in the place where the bag was.

GrowSacks renew the soil

If you use GrowSacks in the same place year after year and throw out their contents after use you’ll find, of course, that the soil surface gets slowly higher. Result: your waterlogged or awful soil will become drier and more healthy. You can then plant acid-tolerant vegetables in the garden soil itself.

A tip: if you plan to grow potatoes in that acidic soil, it’s a bad idea to spread lime on the ground to sweeten it. They hate lime, and grow scabby. But if your ground level has risen after several years’ dumping of GrowSacks, lime would be a good idea for most other vegetables – especially swedes, cabbages, turnips and other related roots.

Is it not dangerous to grow potatoes in the same place year after year? In theory, yes. But when you use GrowSacks you are raising them above ground, in a fresh soil mix each year. Any disease or insect problems that lurk in the ground below are less hazard to plants grown in bags.

Of course, potatoes are not your only option, even at the start of a garden-renewal prroject. Any water-loving plant should do well in a giant GrowSack, if it can get its roots into the damp soil beneath. Unless the pH of the soil below is below 4 – ie. very acid – you should at east get some crop.

You can also grow watercress in giant GrowSacks

Watercress also grows well in giant GrowSacks on boggy soil – provided the bag is not perforated. Despite myths to the contrary, water cress does not have to grow in running water. It will flourish in any moist soil with a neutral pH or an inert porous substance. Pull back the sides of a rubble sack to make a shallow container. Add a few inches of grit or gravel, plus some compost, and water it very well.

Then buy some watercress from a supermarket. Stick the stems in a pot of water. When they develop roots, put them in the Grow Bag. And stand back.

That’s all you have to do, ever, because the water cress – if it lasts its first few weeks – will produce seed. Then you’ll have all the water cress you’ll ever need. But watercress hates dank water. A tip: if you do have running water, like a down-flow pipe, put the water cress in a sink under the tap. If your water cress fails you nonetheless, at least you’ll delight the garden frogs.