One of the hardest things to do in the container garden is transitioniong from Winter/Spring to the Summer garden. The pansies and violas, with their beaming radiant, smiling faces, looking at you in such a loving manner, that brings you peace and joy to look at them. Knowing this, seeing this and feeling this, makes what you have to do the hardest thing! Lifting the robust blooming plants out of the soil and into the trash bags! However, you must constantly remind yourselves that they will succumb to early summer heat and humidity. Pansies and Violas are cold and cool weather plants that reach their peak and die back during the heat of the summer. They do not fair as well trying to keep the alive in containers as you can do in the open ground. In the garden, where the soil is kept cooler by mulching, the shade of summer plants, where there is not as high of an evaporation rate of moisture from garden soil. Yes the garden dries out, but in the flower beds, you tend to water more. Containers by their very nature of being elevated and the sun hits and heats up the containers much more quickly the demand for watering is much higher in the container garden and plant stresses are much more demanding than in the open ground.
When I moved here to the apartment, I was self concious of weight of soil in the containers. The one problem with most people is that they choose containers that are too small, for the luxious blooming plant and the equally large root system that grows to match the top growth, as with hanging baskets, which during summer heat should in most cases be watered twice a day, alas a lot of people do not water until the plants are drooping over the sides of the container. This is why I chose the size containers I chose. I went to Dollar Tree and picked up styrofoam coolers (holds one six pack of cans) for $1.00 each, this takes up some space with in the container, which lightens the load, allows for better drainage, and the roots have a cooler interior space to grow around. The soil mixture I use in my containers, is the greenhouse mix that most all commercial greenhouse operations use, it is “soiless” in that it is based on spaghnum moss, vermiculite and perlite, as well as some added moisture retentive ingredients, it by nature is a sterile mix, to inhibit soil diseases etc. I use it for these properties in the containers, but I also add Miracle Gro potting soil which too is spaghmum peat moss, with other composted materials, so it would not be considered soiless, I have also included this year a new organic soil, that I found at Costco, it is organic and contains Kelp and Alfafa meal. which I always used Alfalfa pellets in the garden to enhance and build up the soil.
The depth of the totes I bought for the containers are key, as it allows ample depth for root growth to move downward, as well as moisture retention deeper down. This system seems to have worked well even with the styrofoam containers inside. I was not sure, when I did this experiement if it would work or not, however I think 4 years of good growth and blooms is proof enough that it has worked.
My plans were to rework the metal balcony rail baskets, to reline them with the cocofiber liners and new potting mix in them as well. I find while these are aestetically pleasing to the eye, they are NOT practical. They are neither wide or deep enough to encourage a good root system. In addition during exceedingly hot days they may require water more than twice per day. I have tried many types of flowers designed for heat and drought. I have found the best, least suffering flowers to be Portulacca (a member of the Purslane family) as you know purslane in the hot, hard, and at time drought ridden vegetable garden, will thrive! This year I looked and last years Portulacca reseeded and there are babies everywhere, alas, I will do nothing to the wire baskets (this year) I had bought Portulacca to put there anyway.