The American Southwest is a vast area, covering all of Arizona and New Mexico as well as parts of California, Nevada, Texas and Utah. The regions of the Southwest are varied and include low deserts, high deserts and mountainous regions, covering USDA zones 5 though 9.

The browns of winter have finally given way to bright green. Leaves are appearing on trees, shrubs and more. April is a great time for desert gardeners to add colorful plants to the landscape and reimagine container plantings. With the warmer weather, irrigation controllers need to be checked, weeds pulled and any remaining frost-damaged plants pruned.

Gardeners in upper elevations can sow cool-season vegetable seeds outdoors, plant bare-root roses and thin fruit as it appears on trees. Noelle Johnson Landscape Consulting All Desert Regions

Adjust the irrigation schedule. As temperatures rise, so do the water requirements of plants. Watering schedules need to change with the season. How deeply you water is also important. Water trees to a depth of 3 feet and shrubs to 2 feet, letting the soil dry out between waterings.

An easy way to determine how deeply you are watering is to take a piece of rebar and stick it into the soil after you have watered. The rebar should go down easily until it hits dry soil. Pull it out and measure how deep the water has penetrated; adjust how long you water until you get to the right depth.

Shown: The Living Desert in Palm Desert, California Noelle Johnson Landscape Consulting Low, Mid- and High Deserts

Warm up landscape color for spring by planting yellow flowering plants such as angelita daisy (Tetraneuris acaulis), desert marigold (Baileya multiradiata), feathery cassia (Senna artemisoides) and damianita (Chrysactinia mexicana).

Shown: Angelita daisy Noelle Johnson Landscape Consulting Grow vines as ground covers. Vines aren't just for climbing up walls and fences. They also make great ground covers. Try growing Carolina jessamine (Gelsemium sempervirens), purple lilac vine (Hardenbergia violaceae), Lady Banks (Rose banksiae) or trumpet vine (Campsis radicans) on the ground.

Shown: Purple lilac vine Noelle Johnson Landscape Consulting Plant herbs in containers. Do you love fresh herbs? Plant a collection of your favorites, such as basil, rosemary, sage and thyme.

Apply a slow-release fertilizer when planting your herbs, which is all the fertilizer they will need for the season. Also, herbs don't like too much water. An easy way to determine when your herbs need water is to stick your finger down into the soil until it reaches to your second knuckle. Water if it's dry.

Shown: Basil, purple basil, rosemary, sage and thyme Noelle Johnson Landscape Consulting Try a succulent as a container plant. Containers aren't just for flowering annuals. Succulents make great container plants as well. They are low maintenance and provide great texture with their columnar, spiky shapes.

Agave, barrel cacti and columnar cacti are good choices for containers. Place them against a wall or flanking an entryway for greatest effect.

Well-drained soil is a must for succulents, so be sure to use a soil mix that is specially formulated for succulents. Make sure your pot has holes for drainage too. Water every one or two weeks in summer, depending on your succulent's water needs and the weather.

Shown: Smaller succulents flank a potted Mexican fence post cactus. Noelle Johnson Landscape Consulting Plant warm-season annuals. Rising temperatures mean it's time to switch out your cool-season annuals for those that will thrive in our hot desert summers.

Celosia, blue salvia (Salvia farinacea 'Victoria Blue'), red salvia (Salvia splendens), moss rose (Portulaca grandiflora) and vinca (Catharanthus roseus) are great choices for a beautiful bed of flowering annuals that can handle the desert heat.

Before planting, amend the soil with 2 to 3 inches of compost and then add a slow-release fertilizer, which will help keep annuals flowering through the summer. You can also add liquid fertilizer every other week, but be careful not to get fertilizer on the leaves, because it can burn them during hot weather.

Shown: Blue salvia Noelle Johnson Landscape Consulting Upper Elevations (over 6,000 feet)

Thin fruit trees. Once fruit begins to form on your trees, it is time to thin them by removing excess fruit. Apple, apricot, peach and plum trees have a limited amount of resources to devote to fruit production. Selectively removing fruit helps to channel the resources to the remaining fruit, which will grow larger. Thin the fruit on your trees so that there is approximately 6 inches between each fruit.

Shown: Apricots before thinning Noelle Johnson Landscape Consulting Sow cool-season vegetable seeds. It's time to get into the vegetable garden and start sowing your favorite cool-season vegetables. Broccoli, carrots, chard, lettuce, radishes and spinach can be directly sown from seed in your garden.

Before planting, work 2 to 3 inches of compost into the soil. You should also add blood meal and bonemeal (following the package directions), which are natural sources of nitrogen and phosphorus.

While it's still too early to plant tomatoes outside, it is time to start them from seed indoors.

Shown: Radish seedlings Noelle Johnson Landscape Consulting Plant bare-root roses. Do you envision a garden filled with fragrant roses? Select grade 1 roses, which have three large canes (branches), whenever possible. Soak your bare-root roses for at least 24 hours before planting.

Amend the soil with compost; mix it with the existing soil so you have 50 percent compost and 50 percent native soil.

Don't fertilize newly planted roses; they need time to grow roots before they can support a lot of new growth. Wait until the first flowers have blossomed before adding fertilizer.

Get ready for May. The temperatures are warming up fast. The cacti are beginning to flower, which means that it's time to heatproof your garden for summer.

Shown: Medallion hybrid tea rose

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