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A better blend
Why the success of your garden lies in the integrity of it's soil

Photos by Matt Haas

April 2016

Itís all in the soil, says John Lewandowski, retail manager at Bluemelís Garden and Landscape Center. "Far too often, Iíve seen customers spend hundreds of dollars on high-quality plants only to take them home and plant them in a cheap 99 cent bag of Ďdirtí without giving it a second thought," he laments.

Yet Lewandowski believes there are discouraged or dejected gardeners who actually have a green thumb. They just have bad or poor soil.

While there are many high-quality custom mixes available on the market in bags or in bulk at an affordable price, many of his customers are choosing to make their own potting soil as they learn the importance of quality to maximize plant potential.

But there are challenges in making a personalized mix, especially the time it takes to hunt down ingredients and achieve the proper ratios as well as the cost. "Chances are you may need to source your ingredients from several different stores, plus you may end up having to buy more than what you need. Some materials arenít generally sold in smaller quantities," he points out.

Hopefully, those challenges wonít be deterrents to the fun of making soil, especially since it is a fulfilling family project. "It would be a great way to get everyone involved and excited about gardening. Plus, it would be a wonderful learning experience," Lewandowski adds.

A shovel and garden trowel are the only tools needed, with gloves being optional. "Most serious gardeners I know love the feel of a good soil and donít mind getting their hands dirty. In fact, they love it," he continues. Since good potting soil is airier or lighter in weight than soil from the ground, it should have excellent drainage as well as water-holding capacities.

Homemade potting soil tips:

A heavier soil as a base gives the mix depth, with peat moss (not peat humus) giving it the necessary lightness and drainage.

Use vermiculite and perlite to add moisture retention, minerals and aeration. Sand can be incorporated into the mix to improve drainage.

Mix soil in a container to minimize mess and speed cleanup time; an outside area that can be sprayed with a garden hose is ideal.

If potting up hardier or woodier plant varieties such as a small shrub, rose bush or fruit plant, a heavier potting mix than one used for flowers is necessary.

Make what you will use for the season, storing excess in a breathable bag or container, and keep in a dry, cool place such as a garage or basement to minimize mold.

As Lewandowski emphasizes, gardeners should know that there are hundreds of different ways to make a good muffin. "Same goes for potting soil," he says.

"So donít get caught up or overwhelmed in making that magic recipe. The satisfaction in making soil comes when you see the difference it makes in your plantís performance versus using a cheap or poor soil," Lewandowski concludes.

Sharon Morrisey, consumer horticulture agent for the Milwaukee County UW-Extension, says there are few benefits to making oneís own container growing mixes. "There are now so many options for commercial, packaged container mixes that the hardest part is sifting through them all to find the mix with only the components you want for the best price," she points out.

Morrisey says that most are soil-less but use some composted materials as the base. "These are lighter weight and easier to work with for that reason. They are also sterile ó whereas mixes containing soil need to be sterilized by the manufacturer, making them a little more expensive."

Packaged mixes may also contain slow-release fertilizer and soil moisture-holding polymers, which add to the price considerably. "Adding slow-release fertilizer purchased separately may be cheaper, especially since it can be added just to the top 1 to 3 inches of soil, and with each watering, washed down into the soil where plant roots can get it," she explains.

Yet moisture-holding polymers may not be a necessary expense. While they do hold more moisture in the soil, they do not really mean you need to water much less often than without them, according to Morrisey. M


This story ran in the April 2016 issue of: