Quick color is what's called for this morning, flowers to brighten the garden before the chicken goes on the barbecue or the guests arrive. That's what 4-inch, or "quart," pots were invented for.
Plants already in bloom are also sold in gallon cans, but the drawback here is that you must dig a large hole, which is a lot of work and disruptive to say the least. Flowers in quart pots, however, need a very small hole and you can plant them amid other plants without disturbing anything.
How you plant and care for flowers bought in quart containers makes a big difference in their success, and some of the basic rules of gardening don't apply. Before planting, it is very important that the plants be watered so the soil in that little pot is thoroughly wet. When they are popped out of the pot, you are sure to find a tangle of roots, but you may not want to untangle them, something you always do when planting anything else. The problem is that they may lose too many roots in the process, wilt and never recover.
Water Them Daily
Then you must water them daily at first, maybe even hourly if the weather is hot. It will take at least two weeks for them to grow any roots out into the surrounding soil and they mustn't be allowed to dry out during this time.
Some plants grow better than others when planted from quart pots. In my experience petunias and marigolds do great, but zinnias and asters do not, but this may have to do with when I planted them; my results are far from conclusive.
Definitely avoid buying any spring-flowering plants at this time of they year. I was frankly amazed that nurseries were still offering quart pots of snapdragons this week, when their time is well past--they do not like heat at all.
So what should you look for this morning, to brighten this afternoon? Here are a few suggestions:
Marigolds as Mainstays
One of my favorite combinations of all time I saw in a garden made by Roger Boddaert Jr., many years ago, for his parents' anniversary as I recall. It was planted mostly from quart pots, in a hurry, and looked great for several months. Marigolds were the mainstay and he used all three sizes--the little French, the taller American, and the giant hybrids--with the smallest in front just like in a class portrait.
Behind these were quart pots of gloriosa daisies, continuing the golden yellow theme, and in front were small plants of the diminutive golden feather, which also has golden yellow daisy-like flowers.
It was a simple but very bright, summery scheme, and to cool it off just a tad, he had planted a few white Shasta daisies, from gallon cans, here and there. Shasta daisies are perennials and will finish flowering soon, but they can be cut to the ground and will flower next year at the same time. So, planting these from gallon cans is worth the cost and work. Marguerites are also in full flower in gallon cans at nurseries this weekend and they are a good bet for quick color.
Blue salvia (again, it is really a dark purple), is a perennial that can be purchased in flower in quart pots, but it does so poorly the second year that it is best planted anew each year. It will however, flower for most of summer so is a good buy in a quart pot. On the other hand, red salvia is an annual and will last a month or maybe more before fading forever. Together, these two very different salvia would get you most of a red, white and blue scheme, a clever Fourth of July planting plan.
For Red, White and Blue
You can find red, white and blue in petunias if you will again settle for purple instead of blue. In containers that get some shade, you could try white impatiens, red bedding begonias, and blue ageratum, each in its own container. Ageratum does surprisingly well in some shade, and the flowers look even bluer.
In containers, put some potting soil in the bottom and then stuff the containers with plants from quart pots. Pack more potting soil into any gaps that remain. Pack is the appropriate word because you want the new potting soil to be less porous than the soil that the plants came with. If it is not, water will bypass the roots seeking the more porous soil you added. Not packing the soil in around the plants is probably the most common mistake when planting in a container.