A friend of mine recently lamented the appearance of her container plants, saying they look very stressed. She wondered what she could be doing wrong, since she has kept up the same routine that made her pots look gorgeous in spring and early summer. I pointed out that container gardening changes with the season, and her question contained her answer: She hasn’t changed her routine.
In the spring, when the days are warm, nights are cool and the sun is not so unforgiving, container plantings thrive. As heat, humidity and the intensity of the sun increase in summer, we need to shift our container-care protocol. Here are some things to think about and tips to follow:
If you think your containers are too small, they are. If you think they are perfect, check again; chances are they are too small. We tend to select pots to fit the plant as it is in the spring, not to accommodate mature plants. Larger plants mean more roots as well as more water and nutritional needs. The smaller the pot, the less soil it can hold, which means it will dry out and heat up more quickly, stressing your plants. Don't be afraid to repot in midsummer if you think your plants have outgrown their space.
Once you have larger containers, make them mobile. When hot, drying winds kick in and the sun beats down, you can give your plants some respite by moving them to a shaded, protected spot in the garden or on the patio. You can keep your large containers on wheeled trivets (with the wheels footed to keep the pots in park, so to speak) or you can use a hand truck, or dolly.
You must be diligent with watering. Pots often need watering every day in the height of summer. Water them deeply in the early morning; a second drink may be needed in late afternoon. More watering means more leaching of nutrients from the soil. You may need to feed more often to compensate for the increased watering routine.
Lastly, too many containers too close together can reduce air circulation—not a good thing when the days are terribly hot. Give your plants room to breathe.