When faced with the pending summer warm-up of their desert homes, people often ask: How should I water my potted gardens as the days grow hotter? As we leave winter’s slightly cooler months, we need to be prepared to adjust our watering each day, until we settle into consistent temperatures as spring blasts into summer.
I say this, because the temperatures could be in the mild 70s one week—and then get pumped into the upper 80s or even 90s in a day’s time. As we enjoy our wonderful winter flowers, we hope to get a couple more months of splendor from them, so we need to make sure they are moist enough to make it through the hotter days—but not overly wet when it cools off.
If you are hand-watering or have your pots on an irrigation system, adjustments are not hard to make, as long as you are mindful. Being mindful means exploring your garden on a regular basis, especially as the seasons change. Take your coffee or tea out in the mornings, and check your pots to make sure they are each doing well.
Our plants have the greatest chance of survival if they are healthy before the heat hits. Proper water and regular feeding (every two weeks with a water-soluble fertilizer) will provide them with the best conditions possible for this challenge.
With fully grown winter flowers and plants now shading the soil, I would expect you are watering your larger pots (greater than 22 inches, that is) every other day in the morning. Check your pots on the non-watering day to make sure the top 6 inches of soil have not dried out. The roots of flowers planted in the fall should be at least this deep, so that is where you want them damp. They should be OK if the top soil line is a little dry.
A water meter is a handy tool to have; otherwise, just insert a pencil. If the pencil comes out with soil clinging to it, the soil is moist. The water-meter reading will be between medium and dry before water is needed. If you do find them dry that far down, be sure to give them a good soak—meaning that water flows out of the drain hole in the bottom of the pot. The general guide for hand-watering is 30 seconds for each 18 inches of soil diameter, with your hose set to a gentle-shower setting.
Irrigation run times will depend on your system and emitters. A dedicated pot line is typically set for five to 10 minutes each day of operation. I have seen some systems running only three minutes, with ample water delivered to the soil. As I said, it depends on your water-delivery methods. You must make sure you understand how to run the system and make adjustments as needed. They best way to learn is to practice making changes every day until you are so comfortable with its operation that you could coach someone over the phone.
While you are out there being mindful, take time to smell the flowers!
Planning for a Delightful Year-Round Pot
I have often talked about planting trees in pots—but a tree I have left off my list, at least until now, is the pineapple guava (pictured below). It’s actually a shrub, but this plant is often grown as a patio tree, keeping its size in a pot to 6 feet. We won’t necessarily see flowers or fruit on the tree due to the absence of the chilling time required to produce fruit, but the gray-green leaves with silvery-white undersides bring a striking and unique hue to your yard. They’re similar in color to the leaves of an olive tree.
Pineapple guavas, like all potted trees, should be put into a pot at least 26 inches in interior diameter. This will give the roots enough soil to stretch out and provide the plant with the moisture and nutrients it needs to thrive. They are not fast-growers, so I suggest you select a plant in a 5-gallon nursery container.
Plant them in a good potting soil that drains well. Similar to Mediterranean plants, pineapple guavas do not like wet feet. They can take full sun, but they will look better if given some afternoon summer shade.
Don’t be fooled by the drought-tolerant listing: You do not want the tree to dry out. If it does get too dry, the leaves will let you know by dropping off the plant. (Remember my “be mindful” mantra!)
The pineapple guava is frost-tender in mid-desert regions, but in the low desert, it will be rather comfortable all winter long. If we happen to get down to 35 degrees or lower, it would not mind a little jacket, in the form of a light blanket. Take it off the next morning after the sun is up.
As seen in the accompanying picture, the Guava can be underplanted with seasonal flowers—making for pure beauty when supported by the perfect pot.
Your March To-Do List
- Monitor irrigation and watering. Be Mindful!
- Deadhead faithfully, and selectively prune longer branches, especially in petunias.
- Use your water-soluble fertilizer every two weeks with a hose applicator.
- Clean up plant debris, including dead leaves and broken succulent stems.
- Begin fertilizing roses.
Marylee Pangman is the founder and former owner of The Contained Gardener in Tucson, Ariz. She has become known as the desert’s potted garden expert. Marylee’s book, Getting Potted in the Desert, is now available. Buy it online at potteddesert.com. Email her with comments and questions at firstname.lastname@example.org. Follow the Potted Desert at facebook.com/potteddesert. The Potted Desert Garden now appears monthly.