Ask a Master Gardener: What’s the importance of watering?


Dry, dry, dry! That is the only way to describe the ground around here.

The pond I use to irrigate the garden is about 16 inches below normal. That is the lowest I have seen it this time of the year.

Looks like we will need a watering plan earlier than usual. Most of the time, I put the watering system in first then plant. It's easier that way. I thought about this topic the other day when I was watering the garden and a gardening friend reminded me it was supposed to rain the next day. I reminded him we are in Mid-Missouri and you can't count on the weather.

Sure enough, it didn't. Most plants in the garden require 1 to 1½ inches of water per week.

If Mother Nature does not provide the water, it is up to the gardener. It is best to plan a watering schedule and not stray too far from it. Plants get stressed when they do not get enough water which makes them more susceptible to diseases.

Although it is good to be aware of Mother Nature, weather is not easily predicted. Holding off your watering for a day if rain is predicted might be fine, but if it turns into several days as the clouds pass over without delivering any rain, it can put your plants in a stressed situation. Then when they do get the water they will soak it up too fast. This can cause problems; from splitting in plants like cabbage to cracking in tomatoes, and to a host of other problems.

As the days start to heat up, if you are using a sprinkler system, it is best to water in the morning. This gives the plants the chance to draw up the water before the sun and wind can evaporate it. This will also help protect the plants from wilting in the hot afternoon sun. If you can't water in the morning, try late afternoon -- late enough to avoid the hot sun but early enough for the plants to dry before the sun goes all the way down. Leaving the foliage wet too long (overnight) promotes fungal diseases. If you are using a drip or soaker hose system, timing is not as crucial, although some gardeners believe morning is best whatever the system.

Although seeds and seedlings need moisture close to the soil surface, the more mature plants require deep watering to develop roots that go down into the subsoil. This will give them some protection during the summer dry spells. Of course the other side of the coin is too much water. You want the soil to be damp (not soggy) about 6 inches below the surface. In waterlogged, soggy soil, roots are robbed of oxygen and may not be able to draw up water. If your plants' foliage begins to brown at the edges or starts to turn yellow and fall from the plant, you may be over watering.

Mixing organic matter such as compost in the soil will improve the soil's ability to absorb and retain moisture. The dense clay particles so commonly found in Mid-Missouri will highjack most of the soil's moisture, making it inaccessible to the garden plants. By adding in some organic matter, you'll give water a place to remain until your plants need it most. A 2- or 3-inch layer of mulch like straw, grass clippings, etc. will help retain the moisture in the ground. Mulch will also help keep the soil temperature a little cooler, and who doesn't like to cool their feet on a hot summer day? Everybody also likes a cool drink of water on a hot day -- so do your plants.

Happy gardening.

Peter Sutter is a lifelong gardening enthusiast and a participant in the MU Extension's Callaway County Master Gardener program. Gardening questions can be sent to [email protected]