We had too much rain for so long and now that we are entering summer, the rain has kind of stopped. How do I know how much to water my garden? KS

This is a very good question and addresses a dilemma gardeners face all the time. Water usage is important for our plants and using water wisely is good for all of us. Here are a few tips to help simplify the process.

There are a lot of sources of information that suggest how much and how often you need to water your garden. These are great places to start but they are just places to start since each garden is going to have unique qualities that determine how often they need to be watered. For example, this time of year the general recommendation is that tomatoes need between 1 to 2 inches of water per week. But even this recommendation comes with a bit of a disclaimer that says, depending on soil type, humidity, and temperature. So how do you know if two inches of water is too much or one inch of water too little? Knowing how much to water is really something you will need to work out for your particular situation.

If you have a nice sandy loam as your garden soil, you will probably need to water at the upper level of this recommendation because sandy soils tend to drain faster. However, if your soil leans more toward the clay end of the spectrum, you probably won’t need to provide the full 2 inches of water each week. That being said, in both cases, we need to factor in humidity and temperature and there is no easy calculation to make that simple to figure out. So, here is how I approach watering my garden and lawn.

Basically, I let my plants tell me. They don’t actually verbalize their needs (which would be awesome if they would) but if you spend time with them and watch them, they will let you know how much and how often you need to water.

When I say I let them tell me, I just watch them to see when they look a little droopy. When they start to look like they need water, it’s time to water. Pretty quick, you will be able to learn how much they need and how often they need it so you can provide them with water on a schedule that meets their needs.

Water needs also depend on the age of the plants because those that are newly planted are going to need more water, more often than those that are well established.

For example, I just set out some new tomato plants. If I don’t water them every day at least, I don’t think they would make it. They have not had time to establish a robust root system yet and so daily watering is the only way to keep them alive right now.

However, right next to them are some oregano and thyme I have had for years. They have a well-established root system, and they get watered every other day when it is hot like this. This goes for my strawberries too.

Once these new tomato plants get established, I will back off a little bit on the watering and here’s why. When we water often, the roots can find all the moisture they need near the surface. This encourages them to develop a shallow root system when what we really want is for them to develop a root system that goes deeper into the soil where moisture is not so dependent on day-to-day weather. This is why the plants that are established can tolerate the heat better because they have deeper roots. So, the best plan is to water less often but deeper.

Now that you have learned the water needs of your plants, you need to place mulch around flowers and vegetables. Mulch is good for a number of reasons. As relates to water, mulch helps maintain better soil temperatures for your plants when compared to non-mulched soil. Non-mulched soil temperatures can vary by 30 degrees or more during the day in the sun, sometimes getting close to 120 degrees. At this temperature, any moisture in the top inch or two of you soil will evaporate leaving your plant’s root dry. The only way to counter this without mulch is to water more often and likely in larger quantities. Mulch requires an investment up front but will work to your advantage in the long run.

I have been taking primarily about in-ground or raised bed gardens, but containers are a little different story. Containers are a closed system. They cannot draw moisture from the surrounding soil, they only have access to what you provide them. Because of that you will probably need to water your container plants more often than your in-ground plants. At this point, I am watering my container plants almost every day; again, because many of them are newly planted, but also because it’s easy for container plants to get dry.

There are a variety of ways to water your plants. You can let the sprinkler system take care of it if you have a good sprinkler system. You can use a soaker hose or a micro-sprayer system. Both the soaker hose and the micro-sprayer systems are good solutions since they deliver water right where it is needed. Or you can hand water which is my preferred method. I like to hand water my plants because it not only gets me out in the garden, but it also gives me time to check up on my plants to see how they are doing.

And last but not least, whatever your watering schedule, watering in the morning is best. It not only gives your plants the water they need right before they are going to need it, but any water that splashes onto the leaves will evaporate before nightfall which helps minimize disease in your garden.

If you engage in good watering practices, you will not only use less water, but your plants will be happier.

You can get answers to all your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, dropping by our Diagnostic Center at 4116 E. 15th Street, or by emailing us at mg@tulsamastergardeners.org.

Photo: Todd Johnson, OSU Ag Communications Services