I’ve been wanting to try out an olla irrigation system for a while now (more on ollas below), but they can be quite expensive to purchase, and then I saw these terracotta watering spikes on Amazon, and I thought they could be an affordable alternative. After testing them out for a while now, I can say that for what they cost, they are well worth the price, and they have made watering my native plants that are all in pots so much more effective and efficient.
The Ancient Inspiration: Ollas
Terracotta watering spikes draw inspiration from the ancient irrigation method known as ollas. Ollas are unglazed clay pots buried in the ground, with their necks sticking out. Water is poured into these pots, and the clay naturally releases moisture into the surrounding soil, nourishing the plants’ roots. This practice has been used for centuries by various cultures, including the indigenous peoples of the American Southwest and parts of Africa.
The science behind ollas, which are unglazed clay pots used for irrigation, lies in the principles of capillary action, evaporation, and the natural movement of water through porous materials. Ollas function as an efficient and water-saving method of providing moisture to plant roots.
Ollas are typically made from porous clay, which means they have small spaces within their structure where water can move through capillary action. Capillary action is the ability of a liquid to flow in narrow spaces against the force of gravity. When water is poured into an olla, it is drawn out of the clay wall and into the surrounding soil due to the natural capillary action of water in porous materials.
This controlled release of water helps prevent overwatering and underwatering of plants, which can be common problems in traditional watering methods. As the soil dries out, it draws moisture from the olla through capillary action, ensuring that plant roots have access to water when they need it.
Ollas are buried in the ground near the root zones of plants. This placement ensures that water is delivered directly to the area where it’s needed most, the root system. By keeping the soil around the roots consistently moist, plants can access water and nutrients efficiently, promoting healthier growth.
Unlike surface watering methods, which can lose a significant amount of water to evaporation, ollas lose very little water to the air. This makes them incredibly efficient in conserving water, which is especially important in arid or water-scarce regions.
The slow release of water encourages the growth of beneficial soil microorganisms, which can aid in nutrient cycling and improve overall soil health.
This ancient irrigation method is highly effective at conserving water, promoting plant health, and reducing the need for frequent watering, making it a sustainable and environmentally friendly choice for gardeners. While ollas are effective, they can be expensive to source, and take a lot of effort to make your own.
Pros and Cons of Watering Spikes
Terracotta watering spikes provide a more accessible alternative for modern gardeners— and I tried them for myself to see if they are worth the investment.
Terracotta water spikes act as a decanter that automatically releases water to your plants in the same way an olla does. The spikes are buried like an olla, and a long neck bottle filled with water is added to the spike as the water source.
So do they work? In short, absolutely! I was watering my native “bush tucker” plants by hand and didn’t like it at all— I’ve automated most of my watering with simple irrigation, and it was annoying to have to hand water these plants. Because they are in pots, they need more frequent watering, but being native plants many of them don’t require as much water as my typical edible plants. If I went away for a week or more, some of them would suffer. I started using these terracotta watering spikes and they worked perfectly.
You can notice that different plants use different amounts of water when you refill them. I’ve used larger wine bottles for those that tend to use more water and beer bottles for those that don’t need as much water.
I refill the bottles probably twice a week at the moment, although this might increase as we head into Summer. To refill them, I just fill the larger wine bottles with the hose, and then I fill the other bottles with a bucket.
Are there any negatives?
They probably need to be filled more regularly than regular ollas, but compared to the time spent hand water my pots this was definitely worth it.
You will also need to have long neck bottles to use them, so you might need to drink a bit of wine or use a bit of soy sauce, before you’ve got enough bottles to recycle.
They need stability so they aren’t suitable for fabric pots and grow bags.
Being terracotta they are susceptible to breaking. I’ve never had any of mine break, but I’ve seen online that a few people have had there’s break and they think it’s from the weight of the wine bottles— I’d recommend using smaller long neck bottles like beer bottles if you’re worried this might happen.
How to Use Terracotta Watering Spikes
- Choose the Right Size: Select watering spikes that suit your pot size. Smaller pots may need just one spike, while larger ones might benefit from two or more.
- Prepare the Spike: Soak the terracotta watering spike in water for a few hours before use. This ensures that it doesn’t absorb moisture from the soil too quickly.
- Dig a Hole: Dig a hole in the soil next to your plant. The hole should be deep enough to accommodate the spike, leaving just the neck protruding above the soil.
- Insert the Spike: Place the soaked spike into the hole, ensuring it stands upright.
- Fill and Monitor: Fill the spike with water. As the soil dries, the terracotta will slowly release moisture to the plant’s roots. Keep an eye on the water level in the spike and refill as needed.
