As the middle of Summer limps lethargically to back-to-school season, we thought we’d talk a bit about summer planting. Is a plant better in a pot or in the ground? Or, as we are often asked this time of the year: “Should I plant it now, or should I wait?”
It’s definitely more of a challenge to plant in the heat of summer. Plants in general are like we humans in the heat: just trying to get by. Their metabolism rises in hot weather, throwing them into stress. While they are making use of the sun to make sugar through photosynthesis, they are also using it up at a faster rate to fuel their other life processes, and may actually use up more than they make on a hot day.
Are they better in pots or in the ground? Pots have several drawbacks. First, they dry out quickly. We make extensive use of sprinklers here at the garden center, and we still have people watering with hoses and water wands all day long this time of year. Wilting is stressful and can cause death of some of the roots, so we are diligent to stay ahead of serious wilting. Second: most nursery pots are black (I don’t know why but it may have something to do with the materials and cost; they tend to be way down on the recycling scale of desirable plastics) and black pots heat up, which is also hard on roots. Our soil here is generally wet from the sprinklers, and this helps keep the pots cooler than they would be on asphalt, but still, given the choice, a plant would rather be in the ground with cooler soil and room for its roots to spread out.
My brother Bruce, who was an avid gardener, lived in the South for much of his life and spent a couple of years in the tropics. I learned a few practical things from him: in the summer, keep your potted plants in a shady spot until you can plant them to reduce stress. Not for months, but if you buy them on Saturday and are going to hold them for a week, put them in the shade.
When you are ready to plant, make sure that your plant is watered a couple of hours before you plant. You never, never want to plant a plant that is dry. Fill the planting hole with water and let it soak into the surrounding soil before you plant. After planting, water the plant again to settle the soil around it. He recommended planting in the evening, so the plant could spend the first 12 or so hours getting settled before the stress of the next summer day.
Once planted, they may wilt during the heat of the day, even if the soil is moist. The poor little guy is losing water faster than he can take it up even if the soil is moist. It should regain some turgor (that is, not look wilty) by evening. Make sure to soak the soil when you water, don’t just spritz the leaves, and water at the base of the stems/trunk; most of the roots are in that original soil ball you just planted, and it will dry out faster than the surrounding soil. You may have to water once a day for the first week or two, especially if they are planted in the sun.
Our garden shop offers lots of watering aids (e.g., Tree Gator Bags) that will reduce the frequency of water needed and get you through the initial establishment phase, or get you through that long weekend away. Don’t buy plants if you are going on vacation for two weeks, unless you have relatives/neighbors/friends that will water them either in the pots or in the ground. Don’t expect Ma Nature to bring enough rain to get plants off to a good start. If you can’t provide water, then it’s better to wait to plant in the Fall.
by Larry Hurley, Behnke horticulturist