Outdoor Container Plants

With the outdoor gardening season coming upon us it’s time to return those plants that have been over-wintering in our nice warm home to the great outdoors.Also, I get to place hanging plants around the outside of the house. Oh yeah!

Over the years I have maintained container plants on the back deck as a sort of mini-kitchen garden. Lettuce, radish, spinach, beets, tomatoes, etc. This year will be no exception. During my rookie days, these containers did not produce very well due to my inattention to the single most important aspect of container growing: adequate fertilizer.

A continuous supply of nutrients and fertilizer is an absolute for lush container bouquets and productive edibles.

After about a month of growing the plants usually began to show signs of the dreaded ‘death-mask’. Browning around the edges, wilting, drooping, that even feeding didn’t help. I learned that my mistake was in not feeding them enough. I was starving the container plants, because I didn’t replace nutrients that were leached out of the potting mix every time I watered.

Now, through the advice of other more experienced gardeners, I use this three-step fertilizer program, and my container gardens flourish.

Step one - Incorporate timed or slow-release fertilizer into potting mix when filling containers. (If the potting mix contains fertilizer, skip this step.) Fertilizer pellets are coated with a polymer that let them dissolve at varied rates; the thicker the coating, the long it takes for the fertilizer in pellets to be released into the potting mix. Most brands feed plants for at least 60 days, and some supply a steady stream of nutrients for up to 120 days. Check the label on any product you buy for this information.

Fish meal pellets are formulated similarly to synthetic fertilizers. Cotton seed meal, feather meal and alfalfa pellets are other slow-release organic choices. All feed plants for about 60 days.

Step two - Apply water-soluble fertilizer every two weeks to supplement the slow-release fertilizer. Water-soluble fertilizers deliver nutrients directly to plant roots and are easy to apply. Just dissolve them in water and pour the liquid into the container for a nutritional boost. Follow package directions for dilution rates and the amount of fertilizer to use on each container. I’ve had great success with fish meal emulsion and liquid kelp.

Step three – Sometimes plants need a quick pick-me-up due to stress or heavy production of flowers or fruit. Deadheading old blooms and cutting back damaged foliage helps to re-invigorate the plant. After doing this, spray water-soluble fertilizer on leaf tops and undersides. The spray delivers nutrients directly to where photosynthesis takes place. Results are dramatic—you’ll see growth or renewal almost overnight.

Note: Use any spray bottle or garden sprayer and always follow dilution rates given on the fertilizer package. Don’t spray leaves when temperatures are above 90ºF or when the sun is beating directly on the plants. The fertilizer will burn leaves. The best time to foliar feed is in the morning or early evening.