Potting Tips part 1

THE PLANT With the correct soil you can grow just about any plant in a pot successfully as long as you maintain the size of the plant so that it doesn’t use water faster than it is being applied.  For example if you don’t limit the size of a Bamboo, Willow, or Apple tree it can easily use all the water the soil can store in less than a day.  Once dry, the leaves either drop or turn an unattractive color.  Blooming and growing also ceases.  Plants that are easiest are the ones that use water at a slower rate.  This includes Succulents, Palms, Plumerias and Conifers.

THE POT SHAPE Plant perform better in taller pots.  This is because any type of potting soil has a characteristic danger zone, the perched water table, at the bottom of the pot that remains saturated (too wet) following irrigation.  This zone is often 2-3” thick.  A taller pot will have a smaller portion of its soil in the danger zone than a short pot of the same volume.  A perched water table is actually helpful if the plant uses water quickly, but very detrimental to plants that are using water slowly.

THE POT COLOR Most plants perform best when the soil temperature is between 55°F and 85°F.  A few plants like Plumeria and some Palms enjoy toasty conditions.  Be aware that dark colored pots can cook the roots in summer.  Plants that should always be in light colored pots are Lavender, Cherry trees and Pittosporum tenuifolium.  Roses and stone fruit trees perform better in cooler soil also.

THE POT MATERIAL Porous clay breathes well, but dries quickly and stays cold during winter.  Glazed pots hold moisture and heat better.  Plastic, Resin and Fiberglass pots are lightweight, retain moisture, and don’t break easily.  Wood containers are quite good, but good looking wood containers are difficult to find.

THE POTTING SOIL The ideal soil provides a constant supply of water and all 13 essential mineral nutrients, allows free passage of oxygen and carbon dioxide , provides excellent support, and doesn’t change over the life of the plant.  Needless to say there is no type of soil that can excel at everything.

More on potting soil next week