For most of the year, plants budget resources for their big spring splurge when flowering and reproduction take priority. They look the best in spring because appearances are everything when attracting pollinators. After the springtime burst comes summer, when they’re depleted and doing whatever they need to do to get by. In fall, plants start hardening off for winter and sending energy to roots in preparation to grow larger and produce even more flowers the following year.

 

As we toggle through the seasons, it’s important to adjust expectations of what a healthy plant should look like. Watering in summer and winter can be tricky because the signs of a plant conserving energy to protect itself against temperature stress are identical to that of a dehydrated plant: browning, leaf drop, and sometimes above ground die-off. But sacrificing leaves is the result of the plant’s calculation of what serves it best, and not necessarily a function of poor watering. Too much water at these times of year can actually hurt plants.

 

If you’re uncertain about the condition of your plants in summer or winter, visit the demonstration gardens at Joshua Basin Water District and Mojave Desert Land Trust. Comparing appearances should tell you whether they’re just hunkering down or if there’s trouble. A few seasonal watering tips are offered below.

 

 

We see plants that look punk in July, and want to go into watering overdrive. It’s a reasonable impulse since we’re conditioned to respond to a fading plant by giving it a drink. Scarier yet, a summer dormant plant often looks dead. It’s counterintuitive but…let them nap and step away from that hose! Asking plants to put out new tender growth in the summer just adds to the pressures that the plant is already navigating. It’s very easy to rot a dormant or resting plant with water by thinking it needs resuscitation.

 

At the very least plants need summer deep watering to keep their roots from drying out (desiccating). If you’ve already been mulching and deep watering, plant roots will be trained deeper in the ground and you’ll be ahead of the game. It’s important to take advantage of any cooling trends to sneak in a good drench to get some stored dampness underground, accompanied by an overhead spray. But don’t water during heat waves. The combination of heat + moisture is conducive to disease so it’s especially important to avoid waterlogging during this time of year. Newly planted individuals will need regular watering per your norm, and light shade.

 

Here’s an article that sums things up nicely and another one to help you keep the faith through the long hot months.  Both talk about native plants but the same principles apply for all desert plants. Mike at Tree of Life Nursery demonstrates his approach to once-a-month summer hand watering.

 

 

WINTER Cover any exposed plumbing on hose bibs and detach hoses. Ever turned on a hose in winter and had ice chunks squirt out? That’s because water freezes inside hoses, and that ice can travel backwards into hard plumbing.

 

We’ve had unusually warm fall temperatures in the last few years which makes it hard to feel like October is really time to taper off watering, but it is. Don’t encourage above ground growth since new growth is especially vulnerable to freezing. Plants wisely use this time of year to develop roots in the more forgiving temperatures underground (thermal mass of the earth). If a shrubby plant has deep roots, it’s likely to come back in spring even if it dies to the ground in a hard freeze. Keep in mind wind chill can freeze plants even when your thermometer reads above 32 degrees. In winter, plants with leaves that are brown hardly need any water except very few deep waterings. In a rainy winter, dormant desert plants need no supplemental watering. But all plants appreciate a cozy blanket of mulch over their roots.

 

 

Foliage spraying is sometimes used to protect plants ahead of a freeze. Some gardeners believe that a casing of ice protects plants by trapping in heat and insulating against wind chill, but the more scientific explanation is that plants are protected because heat is generated when liquids (water) change into solid form (ice). There are advocates on both sides of this method so please do further research as it may not be right for all situations.

 

Our atypically warm autumns haven’t given plants the gradual cooling trends they need to signal metabolic slow-down in preparation against cold. Without the gradual temperature cues, one radical drop can kill a plant and plant damage can also occur when there’s a sudden warm up right after a freeze. In extreme weather swings, expect some loss as adapted plants sort themselves out. Your watering isn’t necessarily to blame in these instances.