Sean has been in the industry of gardening and landscaping since 2006. He is also a certified arborist that specializes in plant health.
Moisture Retention in Soil
Watering and moisture retention is vital and can become the most problematic process of growing plants. Excessive watering can cause a myriad of health problems for plants, and close monitoring is absolutely vital when watering. Root rot, diseases, and pests will take advantage of plants with weakened systems due to excessive watering. Ideal conditions and learning the watering requirements for different types of plants will prevent excessive watering from ever occurring.
Methods to Reduce Over-Watering
There are several methods to properly monitor and maintain moisture to prevent excessive watering. Learning when and how to water thoroughly is the most important. Understanding and researching the watering requirements of plants is equally important. Soil amendments are also vital for plants that are sown directly into the soil or grown in containers to either retain moisture or increase drainage. Several methods can be used to reduce watering, which in-turn lessens the chance of over-watering. Mulching and proper tilling will reduce evaporation and the plant(s) will require less watering.
How to Thoroughly Water
Most plants prefer to be watered with a thorough watering instead of a little sprinkle every day or so. Thorough watering builds a strong and widespread root zone. Soaking the root zone allows all the roots, including the tiny, hair-like roots on the outer edge of the root zone, ample moisture. Research the water requirements for each plant being grown and pay close attention to the soil when determining how often to thoroughly water.
Root zones are much wider than perceived. Only watering at the base of the plant will promote poor roots growth. Watering the surrounding areas of the plant will provide moisture to the outstretched roots. This will let the plant grow strong, gripping roots.
When to Water Container Plants
Determine by Container Weight
The best method to estimate when to water container grown plants is by feeling the weight of the container before and after a thorough watering. Poking a finger into the soil to test for moisture will only test the upper few inches of the container. Poking is very inaccurate and testing by weight is much more precise, but a few waterings and a little experience will be needed before accuracy is spot-on.
Meters can be purchased that are used to determine the level of moisture in soil. These meters are very useful but not necessary.
Dried Soil in Containers
Sometimes a crust will form on the soil in a container which prevents water from penetrating the soil. The crust will cause water to roll off and down the side of the container. Break up the crust with a fork, stick, or anything capable of puncturing the crust. This will allow water to soak the root zone and not flow around the zone and drain away.
Mulching provides great moisture retention and slows evaporation. It also insulates the roots from hot and cold weather extremes. Slowing the process of evaporation reduces the duration between watering and how much water is used. Mulch should be applied 2 to 3 inches thick above the topsoil. A few added benefits of mulch are:
- Suppression of weeds & diseases
- Reduces evaporation
- Aesthetically pleasing
- Reduction of winter damage
- Very slow release of nutrients into the soil
Types of Mulch
A few common fine-textured mulches are twice-shredded bark, compost, cocoa hulls, grass trimmings, and lawn litter. Grass clippings and lawn litter should not be applied in thick layers because the clippings can smother the soil and young plants. Do not use grass clippings that have have come in contact with herbicides. Herbicide residue on clippings and yard waste can kill plants when applied as mulch. Coarse-textured mulches commonly available are straw, bark, and wood chips. Shredded or chipped wood that is dyed may contain petroleum and other chemicals that are harmful to plants. Avoiding dyed mulches is the best way to prevent plant damage via chemical dyes.
Tilling to Prevent Over-Watering.
Till Before Planting
Very clayey soil easily retains water and is not optimal for many plants to grow within. Proper tilling needs to occur so the soil doesn't become waterlogged and over-watered. The surface of clayey soils can easily appear to be very dry and cracked, but the soil may be very saturated below the surface. This is why tilling will prevent over-watering. Mechanical tilling can roughen up the top 6 inches or so, but digging with a shovel provides optimal tillage.
The double-digging method uses a shovel/spade and plenty of hard work. Double-digging is very labor intensive, but allows a great depth for roots. This method greatly benefits plants with deep roots, like roses and many perennials vegetables and flowers.
- Dig down to a depth about the length of a shovel or spade head.
- Shovel out the dirt and place it off to the side of the hole.
- Dig and roughen up any compacted dirt. A pitchfork can accomplish such a task very well. Loosening the compacted layer is the most important step of the method
- Backfill the hole/trench with the recently removed dirt, while adding a little compost or mulch to the backfill. This will facilitate drainage and add nutrients. Do not add large amounts of organic matter because roots do not like passing from one soil type to another. The spread of the roots will be limited if the backfill is heavily amended.
Soil Types and Amendments
Amending soil means to fix soil that drains too quickly or easily becomes waterlogged. Amendments can also add nutrients to the soil. Sandy soils usually require organic matter like compost, mulch, manure, and other organic sources to help retains moisture and nutrients. Sandy soils are loose and roots have a tough time anchoring themselves, which can become a serious problem during winds and stormy weather. Watering needs to occur heavily if plants are in very sandy soils. Succulents, cacti, and other plants that are native to arid, sandy regions will have no problem with such soil, but plants in gardens and flowerbeds may easily have problems.
Clayey soils need amendments that facilitate drainage, like perlite and/or organic matter. These amendments may be hard to work into clayey soils but digging or tilling can work amendments in. Make sure to work amendments deep into the soil.
Waterlogged soil can easily cause root rot. Root rot causes discoloring of the foliage, poor appearance, and a pungent odor is emitted from the roots. If root rot is not corrected, the plant will ultimately die. Amending the soil to facilitate proper drainage along with correct watering methods will cure root rot.
Jill Spencer from United States on October 31, 2012:
I agree with jpcmc: very useful hub! Great job!
Sean Hemmer (author) from Wisconsin, USA on October 30, 2012:
Thank you! You make a very good point, and I highly agree. I'll use that advice and include it. I hit a mental wall and started to run out of things to include, so thanks for the tip!
JP Carlos from Quezon CIty, Phlippines on October 30, 2012:
I love gardening and this is without question a very useful hub. I must add that different soil types hold water differently. The more you know the type of soil you have the better you can water your plants properly. Great job on the hub.