Come September, there are sure signs that the garden is waning. The day breaks late, and the dark comes earlier. The sun is lower in the sky, and is beginning to cast those long shadows that foretell the coming of fall. Though our weather is still firmly entrenched in a summer long pattern of hot days, the over night temperatures are decidedly cool. It is never easy to tell when a container garden has reached its peak, but I am sure anyone in my zone who gardened in containers this summer was working at a peak level all summer long to maintain them. Week after week of extremely high temperatures and near drought conditions meant the delivery of water to container plants was a job never done. My best ally? My big pots. This pot is 40″ square. Routinely someone who is shopping at Detroit Garden Works remarks that only a person with a very large yard would have a pot this big. Though my side garden is actually quite small, this big pot looks right at home. But the best part of its size is the size of the soil mass inside it. That big body of soil retained moisture for a relatively long period of time before I had to water again. Once the plants shaded the soil, the water evaporated at an ever slower rate. At the height of the heat, I only watered this pot every 3 or 4 days. The plants like fewer waterings as well. It is hard on plants to be soaked one day and bone dry the next.
It goes without saying that smaller containers dry out faster. The two small pots in the foreground of this picture are planted with zinnias and the cascading geranium “Acapulco Compact”. Both of these are highly drought resistant. None the less, they needed a good soak every other day, if not every day, due to the small soil mass. Mandevilleas do thrive in high heat, but they also like to be kept on the dry side. The petunias were too dry. As simple as it is to grow petunias, this year’s crop had no end of problems. Petunias decline quickly when they are too wet, or too dry. A summer such as ours made it easy to over water and under water. A small pot soaked through and through was still dusty dry by day’s end. The smaller the pot, or the smaller the root system, the harder it is to maintain an even moisture level.
The scented geraniums were perfectly happy to be dry. The fancy leaved geraniums wanted more water. The zinnias with too much watering was the perfect environment for fungus to take hold. After a long day working outdoors in blistering heat, the prospect of having to fuss over 32 containers was not the first thing on my mind when I got home. The larger pots were more forgiving if I let them go until the morning.
I firmly believe that every fuchsia and lantana comes with a population of white fly – standard issue. Of course the heat brought them out in droves. I completely defoliated this Ballerina tree fuchsia, white flies in a swarm around my head, and put the leaves in a bag that I dropped off the deck into the trash can below. Yes, I immediately put the lid back on that can. That was not the end of them. I did resort to pest strips. My lantana was green most of the summer, as the white flies went first to the new growth. A lot of new leaves and flower buds went in the trash. Though this is the smallest of my pots, it is placed on a north wall that gets very little in the way of sun. It got a little water once a week, and that was enough. Small pots are great in the shade.
This medium sized pot is home to a white dahlia, Acapulco cascading geranium, and white petunias. These white petunias are the best petunias I have this year. I attribute this to the fact that they did not get too wet, nor did they go too dry. How do I tell if a pot needs water? I put my finger, or a bamboo stake down into the soil. If the soil has adequate moisture, it will stick to my finger. Dry soil does not stick to anything. The soil on top may be dry, but of concern is the moisture level at the roots.
The cordyline and trailing verbena in this pot like dry conditions too. This pot has a fairly large soil mass, although some moisture will evaporate from the terra cotta. I was very careful to delay watering this until I was sure the plants were in need. My choice of container plants was absolutely influenced by the National Weather Service 3 month prediction. Their unsually hot and dry prediction was correct.
The Bounce impatiens in these urns need a serious soaking every day now. The soil mass is not that great, and I am sure the plants are root bound. Buck actually watches these for me. Coming home to these plants flopped over makes me grumpy. Their name is fitting – they will bounce back from being too dry. The lavender New Guinea impatiens below them are in a much larger rectangular pot. Once they grew enough to provide the soil surface with some protection from sun, the pot held its moisture much longer.
By and large my containers on the deck look happy. We have a garden going on that took a lot of work to maintain. Even the corgis disliked being stuck outside when it was too hot, but they were too well mannered to ask or expect me to go it alone.
This pair of Italian terra cotta rectangles are home to a very happy group of plants. They have plenty of soil to live in. I watered the smaller plants on the edges of the pot more often than the middle or back section. When the weather is really hot, watering all the way around the rim of a pot is important. Terra cotta can draw the moisture out of the plants on the edge at a much faster rate than the interior plants. I rarely shower a pot. I water with however much I think each plant needs.