Low or No Water Retention in Potted Vegetables

Soil Composition

• The composition of your potting medium determines its water-holding capacity. Sandy soils typically drain too quickly, leaving your vegetable plants struggling to get the water they need for active growth. A lack of organic matter also contributes to rapid draining as your soil particles cannot retain water. Improving the condition and composition of the soil improves its ability to retain water.

Soil Compaction

• Using garden soil or potting soil in containers poses the risk of soil compaction. When this happens, the soil becomes hard and dry and often pulls away from the sides of the container. Water is unable to penetrate the surface of the soil and simply runs through the cracks around the perimeter of the pot. Even though ample water is applied, compacted soil resists the water, directing it to crevices and cracks.

Effects

• Pots or containers with low or no water retention cannot provide the water your vegetable plants need to thrive and produce fruit. When plants receive too little water, foliage wilts and may shrivel and die within a few days. In less dire circumstances where the plant receives some water -- but not enough for healthy growth -- the plant reacts with slowed growth and produces small or malformed fruits. In some cases, stress induced from the lack of water causes blossoms to drop, resulting in no fruit production.

Solutions

• Mixing your own potting medium by combining one part potting soil or garden loam with one part each of peat moss and perlite makes a lightweight potting medium that retains moisture. This soil resists compaction while adding organic matter to assist in water retention. Other organic material, such as compost or well-rotted manure, can be added to the mixture or substituted for peat moss.

Alternative Treatment

• Watering your vegetable plants regularly when the soil dries 1 inch below the surface keeps soil moist and prevents excessive drying. Neglected plants may develop dry, cracked soil that pulls away from the sides of the pots. Submerge the entire plant pot in water and allow it to sit until air bubbles cease rising in the water. This thoroughly moistens all the soil in the pot and may improve water retention, as long as you continue to water the plant regularly. If this does not correct the issue, repotting the plants in new potting medium may be necessary.