Beneficial Insects
Garden Pests
Composting
Fertilize & Mulch
Garden Plans
Quick Tips
Specialty Gardens

How To Monitor Soil Moisture In The Garden

Excerpted from: Gardening Know How

Organic gardening gaphic Adequate moisture is critical for growing plants successfully. For most plants, too much water is more dangerous than not enough. The key is to learn how to gauge soil moisture effectively and to water plants only when they need it, not on a set schedule.

Start With Good Soil

Healthy soil is the basis of healthy plants. You can’t just dig up dirt and put in plants. If you add a little mulch or compost, you are well on your way to making rich, well-balanced soil.

Regular applications of modest amounts of compost — one-quarter inch per season — will dramatically improve your soil’s water retention and help suppress disease.

When To Water

Don’t just water without thinking. Feel your soil! When the soil sticks in your hand and you can form it into a ball, it is moist enough. But, if it barely holds together in the palm of your hand, or if the surface looks hard, baked, or cracked, it is probably dry and it’s time to water.

It’s best to water early in the day so the foliage dries off by evening. When the plants are watered at night, the foliage stays wet for a long period of time and disease problems build up.

Believe it or not, sometimes the best time to water is during or immediately after a rainfall, especially if the rain shower amounts only to a half-inch or so of water. The reason for this is that you want to add sufficient water at the same time to ensure penetration down to 5 or 6 inches. If you wait another day or two to water, you will be adding only surface water, which evaporates rapidly. With only frequent, light watering (or rain showers), you never build up a reserve of water in the soil.

Lose Your Guilt About Wilt

Graphic of a Wilted Plant

Another sign is that the plants may wilt and look especially droopy. However, temporary wilting during the heat of midday does not mean that it’s time to water. Some plants go through an obvious midday slump, especially on very hot days, which is an indication of the plant’s natural adaptation to its environment. Visit your garden again in the early evening and see if the wilted plants have regained some turgidity. If they have come back — that is, if they look perkier — do not water.

How To Measure Your Water

Another way to figure out how much water it follow a general rule of thumb of one inch of water per week.

To measure overhead sprinkling, place 4 or 5 small containers (straight-sided) around the garden while the water is being applied. When 1 inch collects in the containers, that indicates that 1 inch of water was applied to the garden. Gardeners can recording the time needed to fill the container for timing future waterings.

How To Water

Watering the lawn You want to make sure your gardens are receiving an optimal amount of moisture, but you’re not sure how to avoid overwatering plants? We have all been there before. Every gardener has killed a plant or two with kindness. You know you’re over-watering plants when the leaves start to look limp, turn yellow, and eventually fall off. Yes, plants that don’t get enough water will also turn yellow and fall from the plant, but those leaves usually turn dry and brittle.

What you want in a healthy plant is deep root penetration, and the only way that you’re going to get deep roots is if there is water down deep.

There are water meters on the market you can stick in the soil to measure how much moisture it holds. But nothing is cheaper and easier to use than your finger. For potted plants, stick your index finger into the soil down to your first knuckle. If it feels moist, hold off on watering for a few days.

Stop watering your plants on a specific schedule. Instead, lift potted plants and learn how heavy they are when recently watered and when they are dry.

Don’t buy cheap bagged soil when starting a garden bed.

Build the foundation of your garden with compost you produced yourself.

Plants that receive water every day never send their roots deeper to look for moisture and nutrients. This creates a weak root system, leading to a feeble plant.

Watering Systems

Drip Irrigation System

Sprinkler System: The disadvantage of using a sprinkler is that foliage is wetted by water dispersed via overhead application. This could lead to foliar diseases since the foliage remains wet for extended periods of time. An alternative is to lay the hoses directly on the ground near the plant so the water goes where it is needed. A board or rock placed under the water flow will prevent the water from eroding the soil. A good way to direct the water to the plants is to dig a little trench around the plants and allow water to flow into it.

Irrigation System: Soaker Hose, Drip or trickle irrigation is also successful in the home garden. This is done mainly with hoses or plastic tubes with small holes in them that deliver a relatively small amount of water directly to the root zone; by supplying optimum moisture, periods of water stress can be avoided. The hoses or tubes are placed down the rows and water slowly trickles out. Regardless of method chosen, be sure to apply sufficient moisture.

Don't Forget To Mulch

Mulching is perhaps the #1 water-conserving technique for areas that receive less than 40 inches of rainfall annually. Organic mulches reduce evaporative moisture losses from the soil surface, and because the soil stays cooler, they also reduce transpiration water losses. Lay a thick layer of mulch down on top of soil. Do not mix with soil. Renew mulches that are in place for the entire growing season.

Water/Moisture Meters

Moisture Meter

XLUX T10 Soil Moisture Meter
REOTEMP Compost Moisture Meter
Sonkir Soil Moisture/Light/pH Meter
Luster Leaf Digital Moisture Meter
Luster Leaf 1835 Rapitest Digital Anlyzer
General Tools DSMM500 Soil Moisture Meter
HHCC Xiaomi Smart Monitor

Rain Gauges

Rain Gauge

AcuRite 00850A2 5-Inch Capacity Easy-Read Magnifying Rain Gauge
AcuRite 00899 Wireless Rain Gauge with Self-Emptying Collector
Stratus Precision Rain Gauge
OutdoorHome 6” RAIN Gauge.
La Crosse 705-109 Waterfall Rain Gauge

Further Information

All About Aphids & Their Control
The Life Cycle of Plants: Fertilization
The Spruce: How to Make Your Own Fertilizer
Pollination and Fertilization