Homegrown: Container Planting

Mother's Day, which falls on Sunday, May 13, 3012, signals the traditional start of warm-weather planting in Iowa.

Linn County Master Gardener, Becki Lynch, says now is also prime time to plant containers, as the risk of frost should be past.

Many moms will receive a gift of a hanging planter this Sunday (hint to children everywhere.) Becki notes that those plants will grow better if you replant them into a larger container.

Here is more from container expert Becki Lynch:

 Now's the time to plant your containers for the year – since it is early May, we can be assured our annuals will not be damaged by a freeze!  So time to get out there –

Many people simply take the hanging planters that they buy, and hang them at home.  However, your plants will be much prettier, and grow much larger, if you take the time to re-plant them into a larger container, either hanging or on the ground.  First, what soil should you use?

Choosing the Best Soil

To create a successful container garden, the most important ingredient is good potting soil. Choose a mixture that provides a good combination of excellent drainage and aeration.

Many growers like to mix their own and prefer particular blends. Here are 3 simple mixes:

Mix #1?: 2 parts peat: 1 part perlite: 1 part builder's sand

Mix #2?: 2 parts peat: 1 part builder's sand

Mix #3?: 1 part peat: 1 part builder's sand: 1 part pine-bark mulch

Is it really worth it to mix your own if you're a typical backyard gardener? Generally, NO.  The potting soil brands available now are meant to provide nutrients for as much as a growing season, and some now include other supplements that may benefit your plants.  They even include moisture control elements.  However, it's important to remember that these mixes are intended for ONE growing season only and should be discarded and replaced in future years.

Selecting Plants

Select plants that are compatible in terms of light, water, growth and the conditions in the chosen site. Don't mix a shade- and water-lover like impatiens with a dry-and-sunny plant like thyme. Some plants like mint are such aggressive growers they need a pot of their own.

Planting Your Plants

After removing your plants from their original containers, gently tease apart their roots, and remove most of the orginal soil.  If the plant is root-bound and hard, you may want to actually cut apart the root ball.  Next decide which plants you would like in the container, blending colors, sun needs, water needs, and incorporating “Thriller, Filler, Spiller.”  Remember they will grow, so give them room.  Plant them at the level they were in the original container, and water them in well.

Watering Your Container Garden

Pay close attention to watering. For containers in sunny, hot or windy areas, watering twice a day may be necessary. A plant that has outgrown its pot will also need more frequent watering.

And here's where choosing a moisture retentive potting soil, or placing sponges in the bottom of your pots can help.  There are also water-absorbing polymers that can improve the moisture retention as long as you follow the directions on the package.  Some plants are very helpful in that they sag when they need water – quickly recovering as soon as you add water to the container.  Other plants are exceptionally drought tolerant, such as geraniums, marigolds, and zinnias.

Dressing Your Plants

Finally, be sure to top-dress your plants with mulch and a slow-release fertilizer. Even though the surface on the pot may be minimal, you'll be reducing the evaporation rate and eliminating regular feedings.

With just a little work at the beginning of your container season, you will find that your plants will thrive and delight you every day with their beauty throughout the season!