UNITED STATES—Container gardening is overrated. The endemic soil here is not so bad that nothing will grow in it. What is now suburban gardens was formerly famously productive farmland! Soil amendments make the soil more comfortable to plants with more discriminating taste. Plants that are too discriminating are probably not worth accommodating. With few exceptions, planters are unnecessary.
Plants naturally want to disperse their roots into the soil. Drought tolerant plants disperse their roots even more extensively. That is how they find enough moisture to be drought tolerant. If deprived of such root dispersion, they are always reliant on watering. Plants prefer the insulation of soil too. Many types of planters can get uncomfortably cool in winter, and uncomfortably warm in summer.
Besides, planters clutter landscapes, and occupy space on hardscapes. Decks rot. Patios stain.
However, planters are practical for some situations.
The main advantage of planters is their portability. Plants that are sensitive to frost can move to shelter before the weather gets too cool. Plants that are spectacular only while blooming can move for more prominent display during bloom. For those who have not settled into a permanent home, plants in planters are able to relocate. Planters on patios or decks can move about like furniture.
Houseplants obviously grow in planters because not many houses contain enough soil for them to live in. Houseplants can move about just like planters in the garden. That is helpful for those that need a better exposure for winter than they enjoy for the summer. Some might like to go into the garden during mild weather, or for a rinse in light rain. Cascading plants can hang from the ceiling.
Planters can effectively confine invasive plants as well. Montbretia is so invasive that some people will not grow it without containment. (Deadheading to prevent seed dispersion is important too.) Horseradish often grows in tubs for confinement, as well as to facilitate harvest. It is easier to dump the potting media from a planter, and separate the roots out, than to dig roots from the ground.
Highlight: Pink Iceplant
Lavender pink bloom in spring or early summer can be profuse in sunny situations. Individual flowers are like small daisies with yellow centers. They stay closed through most of the morning, then open by about noon. If the weather is conducive, they can be slightly fragrant. However, the evergreen foliage of pink iceplant, Oscularia deltoides, might be even more appealing than the bloom.
The plumply succulent leaves are a delightfully bluish hue of gray. With two sides and a flat upper surface, these leaves are triangular in cross section. Blunt foliar teeth provide a distinctive texture. Foliage is so dense that the relatively thin stems within are barely visible. Stems can blush with pink or purple. Bloom is better, and foliage is denser, with good exposure and occasional watering.
Mature growth gets at least half a foot deep. It can eventually get a foot deep. It slowly spreads about two or three feet wide. With age, outer stems develop roots where they lay on the soil. They can then spread even farther. New plants grow very easily from cutting. Pink iceplant cascades nicely from pots or over stone. It contrasts handsomely with richer or darker colors of other foliage or bloom.
Horticulturist Tony Tomeo can be contacted at tonytomeo.com.