Gardening: Get the most out of your container garden

Nancy Szerlag
Special to The Detroit News

If your plants are drying out quickly at this time of year, there may be more plants in the pot than the soil can support. Your options are to replant into a larger container, remove some of the plants, cut them back or move the pot to a less sunny location. I suggest repotting to a larger container as the roots will continue to grow and the plants will suffer.

To reduce transplant shock, moisten the soil before planting. For potting mix, I add 1 part water to 3 parts soil. It’s best to do this ahead of time so the moisture can move evenly throughout the soil. Putting a plant in dry soil will damage or kill the fine root hairs that bring moisture and nutrients to plants.

After planting, water the container well and allow it to drain. Often the soil will settle, and in some cases, the top of the root ball may be exposed, so be prepared to top it off. The level of soil should be about 2 inches below the rim of the top. It’s a good idea to recheck the soil level after a week or to be sure more settling has not occurred.

Many of today’s potting soils contain a fertilizer charge and claim it lasts anywhere from three to six months. However, daily watering quickly washes these nutrients away, so I choose to add extra fertilizer. When potting up containers, I mix in a good quality pelletized slow-release fertilizer such as Jack’s ClassiCoat into the soil, following the package directions. After about six weeks heavy feeders such as petunias and million bells begin to run out of gas, so to keep the color pumping it’s a good idea to give the plants a boost by adding a water-soluble fertilizer on a weekly basis at half the regular rate. My fave is Jack’s Classic Petunia FeED formulated for plants that do not take up iron efficiently.

Not all plants respond well to heavy fertilizing. Herbs in containers produce lanky, lush growth and loose their flavor when over-fed. Best to give them a fertilizer boost using an organic product, such as Neptune’s harvest, at half strength every two weeks or so. Herbs grown in the ground do fine on their own if compost is added to the soil when planting.

The best time to fertilize containers is in the cool of the morning or in the evening. Avoid feeding during the heat of the day, when the temperatures rise above 85 degrees or when the soil is dry.

Nancy Szerlag is a master gardener and a Metro Detroit freelance writer. Her column appears Fridays in Homestyle. To ask her a question go to and click on Ask Nancy. You can also read her previous columns at