It's possible to grow succulents in pots without drainage holes because they require less water than other plants and you only need to water them occasionally. Their specialized stems and leaves store water for long periods. Classic hens and chicks (Sempervivum tectorum) make a suitable succulent plant for beginners and grows in U.S. Department of Agriculture plant hardiness zones 3 through 8. Mix forms and colors of various succulent types to make a pleasing display.
The Root of the Problem
Few plants, including succulents, can survive their roots drowning in water. For plants to stay healthy, their roots need air. Overwatering causes a number of diseases and without taking steps to prevent wet roots, your succulents may succumb.
Scab is a disease caused by excess water. Symptoms include corky brown scabs appearing on the stems of the succulent. Some species of cactus are especially susceptible to scab. Decrease watering and increase light to fight scab.
Stem and root rot can kill overwatered succulents. Various soil fungi multiply in the presence of excess water. The plants wilt and a brown or black ring appears at the base of the stem, above the soil. If only the roots show disease, cut away rotted roots with a sharp knife and repot the plant in sterile soil. Wipe the blade between cuts with a cloth soaked in rubbing alcohol to help prevent spreading the fungi.
Working With Containers That Don't Drain
A few tricks help minimize the risk of diseases from wet soil. The main trick is to water the plant normally but after a few minutes, tip the planter sideways and drain out excess water.
Double potting helps overcome the problem of no drainage holes in a planter. Grow the succulent in a pot liner or smaller container that can sit inside the larger, nondraining container. Make at least four holes in the liner or small container if it doesn't have them. Layer the bottom of the larger, outer planter with gravel.
After watering the plant, wait a few minutes for excess water to drip out of the smaller container. Lift the plant in the liner from the larger container and dump the excess water. After draining, place the liner or small planter back inside the larger one.
If the container doesn't have drain holes, you'll need to be more careful with watering. Water the container only enough to wet the top 1/2 inch of soil. Allow the soil to dry completely before watering again. It should only need watering once every two weeks.
Potting Soil Choices
Succulents require soil that is loose and drains well. A cactus or succulent soil from the garden center works, or you can mix your own. When preparing the soil for a container, use a mixture that contains equal portions of sand and garden soil. If your budget allows, a better soil mixture is equal parts loam, sand, peat-moss and perlite. Aged compost can be substituted for loam.
Test the soil's quality by moistening a handful of the mixture and trying to squeeze it into a ball. If it is the proper consistency for succulents, the soil will not become compacted but will fall apart.
Cactuses only require fertilizer once or twice each year, during spring and summer, while other succulents should be fertilized three to four times during the summer. Choose a houseplant fertilizer such as 3-7-7 that has more phosphorus than nitrogen.
Dilute the mixture to one-half the standard concentration recommended on the product label, so mix 5 to 10 drops in 1 quart of water instead of 10 to 20 drops. Check the instructions as rates vary by brand. Soak the top 1/2 inch of soil around the plants completely. Use the fertilizer solution in place of a regular watering.
The Right Light
Succulents need the right amount of light to keep them healthy. Outdoors, place them in full sun or part shade. Indoors, placing the planter near a sunny window should provide enough light, but a cool white fluorescent tube is a good substitute if direct sunlight is lacking. Place the tube 6 to 12 inches above the plant for 14 to16 hours each day. Use a timer to help automate the process.