Hydrozones

Some plants, such as lettuce and broccoli, need a lot of water. Succulents and herbs need far less water. If these plants are grown together, somebody is getting too much, or somebody isn’t getting enough. Hydrozoning refers to the practice of growing plants with similar water needs together.

Watering can (Alexas_Fotos) Pixabay

Benefits of hydrozoning

Grouping plants with similar water needs makes your job as a gardener easier. Areas that need lots of water get more attention, while areas needing less water can be irrigated less often. This practice conserves water resources. More importantly, it keeps plants healthier and less prone to pests or diseases.

Overwatering and underwatering both set the stage for problems in the garden. With mixed water use plantings, some plants are getting the wrong amount of water. By grouping plants according to their water needs, you can provide exactly the right amount of water in each planting area, and everyone is better off.

Succulents require very little water, but you can't eat them (Kate Russell)

Designing for hydrozoning

The easiest way to design your hydrozones is to put plants that need the least amount of water furthest from your water source while placing plants that need more water closer to your hose spigot. Of course, for perennials that are already in place, this isn’t an option. But you can still use the hydrozoning concept. For example, I have several fruit trees in my yard. Each tree has an irrigation ring around it. These trees can use a lot of water in summer. I also grow a fair number of tomato plants. I have found that it simplifies everything, irrigation-wise, to grow my tomatoes around my trees. That way, I put water in the irrigation rings and both types of plants thrive. My potato bed, on the other hand, is at the far back of my yard. Since potatoes rot when overwatered, making it a little less likely benefits me and my plants. You will probably find that crop rotation puts your planting beds closer to or further from your water source from year to year, but you get the idea.

Zucchini grows well next to a fruit tree irrigation ring (Kate Russell)

Which plants go into which hydrozones?

Each garden is unique, but we can make some generalizations about which plants have similar water needs. And those water needs are not simply about irrigation. Rooting depth is another factor. Some plants have shallow root systems that need frequent watering in summer. Other plants have deep roots that allow them to collect some water for themselves. And those water needs will change during a plant’s lifetime. Creating fruit or seeds is hard work for a plant and they need extra water to make those beans, squash, and tomatoes. Even those potatoes need more water when tubers are setting.

• Heavy water zone plants: beets, broccoli, Brussels sprouts, cabbage, carrots, cauliflower, celery, corn, cucumbers, leeks, lettuce, onions, peas, peppers, raspberries, spinach
• Moderate water zone plants: asparagus, beans, eggplant, kale, melons, potatoes, rutabagas, squash, tomatoes, and turnips
• Low water zone plants: cowpeas, herbs and many edible flowers, okra, parsnips, rhubarb, sweet potatoes

Keep in mind that specific cultivars may have different characteristics than the rest of their family when it comes to water needs. Tepary beans thrive in deserts, while other bean species need more frequent watering.

You may have to experiment with hydrozones in your landscape, but that’s okay. It’s one of the joys of gardening, in my opinion. One project or plant may feel like a disaster one year. The next year, it may be a complete success. As you learn more about your soil and the plants you grow, the better able you will be to give them the water and care they need to thrive. Hydrozoning is one way to achieve that goal.