Miniature man-made aquifer

Ever dreamed of having a garden that stays green throughout droughts? Do your water-hogging plants keep you from taking more than a week-end off?

The solution might be right under the ground: set up a small-scale aquifer for your thirsty plants to dip their roots in!

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Setting up the aquifer

It’s really just as simple as it looks! The key to retaining the water just at root level for the plants lies in the hydrogel powder. With water, the water crystals expand and will nourish the plants for a long time.

The secret to success: hydrogel crystals

Hydrogel, which goes by nearly a hundred names like water crystals, Polyter, jelly balls, Orbeez and the like, is a chemical compound that retains water by swelling when wet, and then slowly releases it to dry.

Although it sometimes comes from organic, natural sources, it’s most often synthetic, which is why we prepared a page on precautions related to hydrogel products.

These water beads swell to absorb up to a thousand time their weight in water. It only takes a few hours, at most a day, for them to swell to maximum capacity.

What is special is that plant roots are able to drill their roots in the crystals or pearls and extract water from them, much as they would a bit of moist soil or rich humus.

This makes hydrogel ideal for watering plants because it makes water available exactly as a plant needs it while protecting it from drowning.

Creating the water retention layer

Take several good-sized basins and embed them in the growing bed. Each basin should be at least a foot across (25 cm), and you can also use windowsill containers if you want the spots of green to form a more linear shape.

Space them evenly so that all future plants have a chance to send their roots over. Some plants should be planted directly above the basin, especially taproot plants or plants with roots that dive deep. Plants with surface-running roots can be planted outside the basin, around the periphery. They’ll send roots over the edge of the buried basin and will find the water reserves easily.

In this project, the basins were spaced about three feet apart (75 cm).

Throw a handful of crystal water powder or pellets in each basin and let it swell overnight. Don’t put too much or you’ll have trouble containing it when it’s swollen with water. Providing a layer 1 inch thick – after water absorption – along the bottom is more than sufficient even for the most thirsty plants.

Optional irrigation hose

A single black foot-wide basin is half full of water crystals that have swollen after absorbing water.If you live in a spot that really almost never gets water, you can run an irrigation hose over the pans. No need to drill and reach through the basins, simply cross over them.

  • Use hoops if you need to fasten the hose to the ground.
  • Try to angle the hose so that the drip valve section above the pan is curved towards the bottom.
  • Fastening hoops and wedges just outside the hoops will work great for this.
  • Doing this ensures water drips into the pan and doesn’t leak out.

But in most areas, you won’t need to irrigate at all: with the hydrogel, rainwater will be more than enough to cover the plant’s needs even over weeks of drought!

Filling up the flower bed

Two basins, loaded with hydrogel, are buried under soil and compost to provide a growing bed for plants. A hose snakes through for irrigation.Cover the hydrogel crystal layer in the pans with nutritious compost mixed in with regular garden soil. You can bury the pots slightly so that the rims are 1 to 2 inches (2,5 to 5 cm) under the soil level. This makes it possible for roots of nearby plants to join the miniature aquifer.

  • One third compost at most should be mixed in with two-thirds garden soil.

After that, plant your flowers, bulbs, perennials as is customarily recommended.

  • For annual flowers, you can try the pot-in-pot technique which makes them very easy to replace after they die off in winter.

When you’ve finished placing and planting all your pots, you can cover the snaking irrigation hose and remaining soil with the mulch of your liking. Here, wood chip mulch was used but ramial chipped wood or pine bark mulch will also look great.

Basins filled with hydrogel crystals provide water for various plants like coleus, coral bells and ferns, covered with wood chip mulch

In this garden bed by Nature & Garden contributor Keith Hall, both leaf plants and flowers are showcased.

You’ll find beautiful fern (Japanese holly fern in this case), vinca minor, peperomia, coleus, coral bells and impatiens flowers at the top and center are just starting to bear flowers!


Credits for images shared to Nature & Garden (all edits by Gaspard Lorthiois):
Keith Hall,
Nature & Garden contributor