Container Gardening
by Carolyn Carpino, UC Master Gardener

Mother's Day has come and gone and many of us were presented with beautiful container plants as gifts. Unfortunately, we now have to keep them alive! Have you found it's a struggle to keep potted plants healthy in our broiling summer heat? You're not alone. I killed more than my share of plants before I learned the ins and outs of container gardening. First, if you're willing to place the pots in a partly shaded location and water daily, you can probably grow almost anything in a pot. Mother's Day containers are usually made up of colorful plants like annuals and hydrangeas that need a lot of water. They will need a sheltered location, lots of water, and frequent doses of liquid fertilizer to survive in their hot, dry potted environment. An easier choice might be to plant them out in your garden. Try to do it before the plants die, not after!

But what do you do if you love the look of pots in your garden, and still want to take a vacation without coming home to a bunch of corpses? Here's some tips for successful container gardening in the Central Valley:

1) Choose big pots, at least 14 inches across. Small pots are, in most cases, doomed to failure. A large pot provides a greater soil volume, holds more water, and keeps the soil cooler than a small pot. Plastic pots and the new lightweight terracotta look-alike pots don't dry out as fast as terracotta. Nothing has the beauty of terracotta, however, so that's usually my choice.

2) Plant drought tolerant plants. You need plants that can dry out and bounce back. Good choices are one-gallon flax, crape myrtle, windmill palms, and citrus. Anything that is described as "drought tolerant" or "takes the heat" is a good bet. Plants that tend to get too big and fall over in your garden, usually due to too much water, will be better behaved in a pot. I was ready to pull out all my red fountain grass until I planted some in a pot. Now it's a graceful, moveable addition to my garden. Invasive plants, like oregano and mint, are kept in check by planting them in pots.

3) Choose succulents to substitute for annual color in pots. Plant a broad, shallow pot with a collection of succulents. Try different varieties of jade for height, hen and chicks in shades of green, yellow and pink, and other succulents to drape over the edge. They can be bought in tiny pots and grouped together with a rock or two into an artistic arrangement. Best of all, if you break a piece off and stick it in the ground, it will root and you will have a new plant. Our original pot has given birth to several others around the garden.

4) Place pots carefully. Unless you want pots to be totally dependent on you for watering, place them in the garden where they'll be watered by your sprinklers. Supplement with an occasional soaking and you're in business. On the patio, run a drip line off a nearby sprinkler so the pot will be watered when the sprinklers run. Group your pots for the most impact and easiest care.

When planting pots, use commercial potting mix or make your own to save some money. Master Gardener Norm Phillips shares this recipe used by growers and universities: to make 6 cubic feet of mix (one contractor's wheelbarrow) mix two parts peat moss, 1 part perlite, and 1 part vermiculite. Add 8 oz. dolomite lime, ½ oz. 5% iron, 4 oz. super phosphate, and 6 oz. Osmocote (10-10-10). Dampen, mix, and store in a 33 gal. trash can.

You might also add a small amount of polymer crystals, which absorb water and release it slowly to the plant. Don't place gravel in the bottom of the pot. It just adds weight and is not needed for drainage. Master Gardener Betty Coffelt suggests placing some toilet paper or a paper towel at the bottom of the pot to keep soil in and bugs out.

Potted plants can add so much to our porches, patios, and gardens. With the proper choice of pots and plants you, too, can have gorgeous healthy container plants that add a whole new element to your landscape.

June 5, 2003