Plants That Can Stand The Heat

(CBS)  Saturday is the first day of summer, and garden designer P. Allen Smith suggests a few plants that will last throughout the season.

He introduced a variety of plants on The Saturday Early Show that not only thrive in the heat, but promise to fill your garden with color all summer long.

The plants he suggested can be exposed to the full strength of the sun and don't need a lot of water. They are all annuals, plants that gardeners primarily use in containers, as borders or as accents in other beds. In a warm climate, some of the plants can be perennials. For instance, Smith says he grows Wandering Jew all year long in Arkansas, but the same plant would never survive a New York winter.

As the summer wears on, even the heat-loving plants seem to lose some of their luster. Chances are, Smith says, you can remedy the problem fairly easily.

First, he says, make sure the plant gets a lot of sun, if it needs it. Brightly colored foliage tends to turn green or dull if it receives too much shade. The green is a result of chlorophyll in the plant's cells coming to the top of the leaves in an effort to get the starch they need from the sun. Smith suggests exposing the plant to more sunlight because it won't force the plant to reach for starch, and the leaves will return to their normal colors.

It's also essential to fertilize these plants all summer long. Smith suggests fertilizing annuals when watering them. Plants expend a lot of energy to generate blooms. If you want them to continue to bloom, you need to feed them well.

If your soil is sandy, you need to look for a fertilizer with "trace elements," advices Smith. All fertilizers are a combination of nitrogen, phosphorus and potassium. Some types of fertilizers also include minerals such as boron, zinc and lithium, which your plants need in small amounts.

If your soil contains a lot of clay, you probably do not need to worry about including trace elements in your fertilizer. Smith says not all fertilizers contain trace elements, so it's important to read the label and look for it.

If the plants' leaves are turning yellow, they may be lacking iron. Smith says this is a common problem and can be easily solved by buying an inexpensive iron supplement at your garden store. You spray this on your plants or pour it directly on the ground. One application should solve the problem. Although low iron is a bigger problem for trees and shrubs, it will also affect annuals planted directly into flowerbeds.

Finally, Smith says, consider mixing a slow-release fertilizer into your potting soil when planting annuals. As the weather gets hotter and plants need more nourishment, the fertilizer automatically will release more nutrients, without any help from you.

Here are some plants Smith recommends for the hotter weather:

Coleus: Smith says it is easy to grow coleus by nurturing stem cuttings.
Some types of Coleus are:

• Tilt-a-Whirl: Speckled scarlet and yellow, grows up to three feet tall.
  
• Molten Lava: Deep magenta, also grows tall.
  
• Copper: A medium-sized coleus.
  
• Kiwi Fern: Also medium-sized.
  
• Trailing Rose: As the name suggests, a trailing coleus.

Strobilanthes: This plant has metallic purple foliage and it grows full and round. When visiting a nursery, Smith says, you can just ask for "Persian Shield," which is a variety of Strobilanthes.

Artemesia: Oriental Limlight is another full, round plant, with lime-green foliage. Smith says it actually prefers sandy soil and doesn't need any fertilizer.

Cordyline: Red Sensation is a grass-like plant with red leaves good for adding height in a container garden.

Variegated Sedge: This is a true grass that is a combination of creamy yellow butter and green.

Wandering Jew: This plant has a purple color with cream variegation. It's a trailing plant that can serve as ground cover, says Smith.

Cuban Oregano: This plant has fat round leaves, almost like a cactus.

Smith says the following heat and drought-resistant flowers compliment the above plants.

Petunia: Almost everyone will recognize petunias, Smith says, because they are easy to grow and many plant them. In the past their blooms were quite fragile, looking like tissue paper in the rain. Now, they are being grown to better withstand bad weather.

Calibrachoa: These blooms look like mini petunias. Smith says calibrachoa bloom beautifully all summer long.

Lantana: These plants are a little taller and compact. The Carlos variety of the lantana has bright red and orange colors.