Cinco de Mayo is a confusing holiday. Some people think wrongly it's Mexican Independence Day, while others will earnestly try to explain to the best of their ability how the day commemorates a Mexican victory in a battle with the French that was only followed by subsequent losses. For some, it's just St. Patrick's Day with piñatas instead of shamrocks. Advertisers, however, would like you to believe Cinco de Mayo kicks off summer. And while that too is a magical advertising lie, the warmer weather does mean it's time to become hyper-vigilant about making sure your plants get enough water.
Watering your plants incorrectly can be a great example of good intentions gone wrong. Apart from simply over-watering your plants, watering them too frequently can also be problematic. This is when you stroll by your plants and give them a little water every day just to make sure they're getting what they need. "Watering frequently but superficially encourages plants to develop smaller root systems, which means they will suffer during hot, dry weather," writes Willi Galloway in a great book called, Grow, Cook, Eat. Galloway stresses it's better to water your plants less frequently with more water than more frequently with less water.
As far as knowing when to water, Galloway advises against a set schedule and instead recommends checking the soil. "This process is quite simple: just stick your pointer finger into the soil. For plants with shallow root systems, you'll need to water when the soil dries down to the top of your first knuckle. For deeper-rooted plants, wait to water until the soil dries down to the top of your second knuckle." Galloway adds this caveat, "Seedlings need constant moisture in the top layer of soil as their root systems establish. Once the plants actively begin to grow new leaves, you can begin reducing how often you water."
So, how do you know how deep or shallow your root systems are? Salad greens are shallow-rooted crops, while tomatoes are deep-rooted crops. The site Farm Flavor has a handy primer for how deep or shallow root systems are for vegetable crops.
Water your plants in the early morning when temperatures are still cooler. This decreases the chances of evaporation. Watering in the daytime not only increases evaporation, but water that gets on the leaves can burn them. If your plants look like they're wilting in the mid-day sun, don't panic and water them. What's happening is water isn't being taken up by the stem quickly enough to distribute through the leaves. You might want to consider a larger container for your plant if this is the case.
Watering in the evening is also an option as temperatures cool off, however if the leaves are wet during the evening this increases the risk of your plant getting mildew or fungus.
This being Southern California, it would be unethical to not talk about water without talking about conservation. And while part of me is still convinced water conservation is not a priority in Los Angeles as long as water-hogging lawns are still a thing, it doesn't mean we can't still be seeking alternatives as individuals. If you own your home or have a cool landlord that's into this kind of stuff, consider looking into gray water alternatives to water your crops. Gray water, or greywater, is water that's been used to wash dishes etc. (but not used to flush toilets etc.) that can be reused. Also, drip irrigation can also be an effective way to use less water if you have the funds and the facilities for such things.
And always add a layer of mulch. It helps retain soil moisture.
And never water with beer, no matter what holiday it is.