Fill large flowerpots with a glorious assortment of annuals for a colorful, easy to maintain container garden. Recently big, tall pots filled with flowers have become the fashion statement. Big pots are wonderfully versatile. They can be placed anywhere, filled with wonderful assortments of flowers, and new additions can be easily added when bare spots appear.
They're usually filled with interesting combinations of annuals. Sometimes foliage plants such as ivy, myrtle, dracaena or small palms can be used for accents or to drape down the sides. Summer bulbs like cannas work well. Ornamental grasses can be used too, alone, or with other plants. Topiary and small fruit trees are other possibilities.
The best kind of pots to buy are the big light weight plastic ones that look like clay or stone. They can be moved about easily and taken indoors if need be or a frost threatens. Though plastic, they do look like the real thing, unless you tap them. They are not inexpensive.
Regular clay or glazed pots weigh a ton and take two strong men to move. Since they crack when water or soil freezes inside them, they must be moved indoors in northern areas which is a heavy chore. Another option is cast concrete pots, that look like expensive stone ones, and don't crack in winter, but they too are very heavy, especially when filled with garden soil.
What to Fill a Big Pot With. To lighten the load, use a lightweight planting mix, not garden soil. But instead of filling the whole pot with the growing mix, fill the bottom with the plastic styrofoam "peanuts" that everything shipped in the mail comes packed in. Then put a thick wad of newspaper above the plastic peanuts so that only about 6 or 8 inches of the top has the planting mix, or light weight peat moss which works, too.
If you want to grow your plants in regular garden soil, put them in small or medium ordinary red clay flowerpots (not plastic) and stick them in this top growing layer. Red clay pots absorb water from the mix or the peat moss and draw it into the plant roots. Pillow Planting.
This is another neat trick for making it easier to grow in big pots. Buy a plastic bag of moist peat moss. Punch several drainage holes in the bottom of the bag and lay it across the styrofoam peanuts base. Then cut "x"s in the top and put in the plants, or even filled red clay flowerpots. Hide the top of the bag of peat moss with mulch or wood chips.
One nice thing about peat moss is that it holds a lot of water, so if you soak it thoroughly, you don't have to water so often. But caution: don't let it dry out or it turns hard as rock and you have to trickle the hose into it overnight to get it to absorb water again. Water.
Potted plants have to be watered regularly, sometimes once or even twice a day if it's hot and sunny. How often depends on their exposure (sun or shade) and how much is growing in them, and how much fertilizer they are given. Push your finger into the soil to see if they are dry, or use a water meter.
Needless to say, be sure there is a hole in the bottom of all pots, big and little, for water to drain out. Also don't leave a pot over the winter with water inside, for if it freezes, the water will expand and may crack the pot.
Fertilizer. When growing in pots, fertilizer is a must to keep things blooming because potting mixes and peat have no nutrients. So, use a liquid fertilizer as often as needed to keep things flowering. Some techniques that work are either a low concentration with each watering, or regular weekly fertilizing, or slow release, long acting fertilizer pellets or spikes. Plants actually need about 13 different chemicals like calcium, iron, magnesium, manganese, boron, zinc and such, in addition to nitrogen, phosphorous and potash. The best liquid fertilizers have some of these trace elements. Some fertilizers encourage more green foliage (usually high nitrogen) while others encourage flowering (high phosphorous and potash). Sometimes strange trace element deficiencies appear and can be recognized by peculiarly colored the leaves or salt deposits may build up in the soil from fertilizers.
Starting Over If the plants start to look sickly ,dig them up, throw out the old potting mix and put in fresh fill. Then replant the flowers. And while you're at it, add some new ones to keep the pot looking flamboyant and overflowing. Change colors, change design, try grasses, try colored foliage plants, have a ball.