Planting in containers is a simple way to add beauty and additional growing areas in your yard. Unfortunately, watering plants in containers isn’t always simple. I have tried many different methods for watering outdoor potted plants through the years. I’ve found the best way to water outdoor potted plants is by using ollas.
The best way to water outdoor potted plants
Problems with watering outdoor potted plants
- It is difficult to run drip lines to pots. In addition, the drip lines are often unsightly.
- Containers on drip irrigation need to have their own timer because they must be watered more frequently than plants in the ground.
- Containers dry out quickly and need to be watered often. For example, in hot dry places like where I live in Arizona, containers dry out very quickly during the summer and may need to be watered twice a day.
- Hanging baskets need to be watered several times a day to keep plants from dying in the hottest months of the year in Arizona.
- Hand watering containers is time consuming (especially if you have to do it more than once a day!)
- Watering just the top of the outdoor potted plants isn’t effective, but watering until water runs out the bottom can waste water.
- If containers are only watered shallowly, the water doesn’t get to the roots.
- Finally, outdoor potted plants are often watered too quickly and water is not absorbed by the potting soil. Instead, the water passes through the container and out the drain hole.
What is an olla?
Simply stated, ollas are terracotta pots that you bury in your garden or container and fill with water. The porous nature of the terra cotta allows the water inside to seep out slowly to water plants at the roots.
The best way to water outdoor potted plants is by using ollas
For example, I planted this container at the beginning of July in Arizona. It gets full sun. I refill the ollas each morning and the plants are thriving, even though I planted them during the hottest month of the year.
Why are ollas the best way to water outdoor potted plants?
- Ollas do not need water lines going to or from the plants.
- The plants’ roots draw water as needed from the ollas.
- Refill ollas as often as needed. Ollas need to be refilled more often in warm, windy and/or dry weather – less often in humid or cool weather.
- Using ollas prevents water loss through over-watering the pots. Simply fill the olla to the top rather than flooding the plant until water is lost in the drain hole.
- Refilling ollas is easy. It’s a great job for kids to do in the garden. When the olla is full, stop watering. This takes the guesswork out of wondering how much to water.
- The water is absorbed slowly by the potting soil, rather than passing through the soil quickly to the drainage hole. As a result, the roots retain more of the moisture.
Things to keep in mind when using ollas to water outdoor potted plants
- As an example, here in Arizona during the summer, I refill my ollas every day. As the humidity increases and temperatures drop, I fill them less frequently. Consequently during the winter, I fill them once or twice a week.
- Because wind is very drying for plants, if it is windy check your plants more often to make sure they are watered enough.
- To be sure, the type of container or pot used makes a difference in how often to water pots. If using terracotta, clay or other porous pots, they dry out more quickly and the ollas need to be filled more often. Metal, glazed and other non-porous containers do not dry out as quickly.
- Be certain to use the right size olla for the container. Ollas come in several sizes. A very large container will need a large size olla or several small ones.
- Keep the lids on the ollas because standing uncovered water is a breeding ground for mosquitoes.
- Use mulch (compost, bark, rocks) to slow evaporation from containers.
Use ollas to keep hanging baskets from drying out
- When using an olla in a hanging basket, consider using a liner that retains moisture as well.
- Hanging baskets are heavier with a filled olla inside – make sure the plant hanger can support the additional weight.
Directions for using an olla in a hanging basket:
- Place water retaining liner on top of coconut coir liner
- Add olla
- Fill hanging basket about half full with potting soil
- Add plants
- Fill in rest of hanging basket with potting soil to the level of the coir liner
- Hang basket on hook
- Fill olla with water
This hanging basket was planted with an olla inside at the beginning of July. I refill the olla with water each morning. It gets full sun and yet the plants are thriving.