Unlike perennials that grow back year after year, annuals complete their entire growing cycle, from seed to flower to seed, within just one growing season before dying off. Though they may only last for less than a year, however, many annuals are some of the most lusciously beautiful flowers you can grow.
This guide will showcase eight particularly lovely annuals that also happen to be hardy in hot and dry conditions.
8 Drought-Tolerant Annuals That Can Thrive Even in Hot and Dry Conditions
Here's a quick summary of the eight heat- and drought-tolerant annuals that will be detailed in this article:
- Moss Rose
Native to Mexico, zinnias are easy to grow from seed. Sow them directly in the garden. They love heat so much that when the weather is cool, they don't grow or flower very well.
They especially prefer hot, dry weather once they are established and make perfect cut flowers. One of the best parts about zinnias is that the more flowers you cut, the more the plants produce.
- Appearance: It's available in a wide range of colors from white, red and yellow to orange, pink and plum. Blooms can be single or double, and they don't need to be pinched back or pruned.
- Size: This pretty plant grows from a dwarf 10 inches to cutting types of 3 feet.
- Cultivation: If you are sowing indoors, make sure they have good air circulation to prevent mildew. Another way to prevent mildew is to soak the soil when watering instead of using a spray. Also be careful not to overwater these plants.
How to Grow Zinnias From Cuttings
Cut right above a leaf joint, removing extra foliage. Place ends in boiling water for 20 seconds, and then place in warm water for several hours.
Zinnias were once called everybody's flower and poorhouse flower, because they were so easily grown and common looking. The common name, garden Cinderella, alludes to the transformation that the zinnia underwent. In 1886, a French botanist produced the first double zinnia in bright colors, and in 1920 Luther Burbank produced the first dahlia-like zinnia.
Native to Africa and also known as vinca, this is one of the most heat tolerant of all annuals. Thriving in full, hot sun, it blooms prolifically from early summer until frost.
It is particularly useful as a ground cover, because it grows equally as well in sun or shade. Though blooming—which occurs in late spring—is much better in the sun.
- Appearance: Periwinkle comes in colors of rose, white, red, orchid, pink, apricot and bluish, and often with a contrasting center. It has a waxy, lush foliage that grows rapidly in full sun.
- Size: The plants grow 10 to 20 inches tall, and they spread almost two feet across.
- Cultivation: Growing these flowers from seeds can be a bit taxing on the inexperienced gardener. They should be sown indoors in northern areas, and they need total darkness to germinate. Not only do the seeds need to be covered with dirt, they need to be covered in black plastic and placed in a closet. I always get mine from the local nursery, as it makes things much easier.
How to Grow Periwinkle From Cuttings
Either burn ends or dip in boiling water. Place in cool water overnight.
Rosy periwinkle, a tropical species, contains an alkaloid necessary to make the drug vincristine, which is used to treat many forms of cancer.
3. Moss Rose
Native to South America, moss rose needs little water once it's established. It is heat and drought tolerant and thrives during a long hot summer.
The tissue paper-like petals close at night, and they create colorful ground covers. These are also a great plant in hanging baskets.
This flower is also a hardy annual that can take some cold weather, so it won't be killed by a light frost and will bloom well into the fall.
- Appearance: Flower colors are yellow, orange, cream, white, red, scarlet, pink and fuchsia, and you can usually find mixes of colors when you buy plants at the nursery.
- Size: Moss rose only grows about four to six inches tall.
- Cultivation: Sow the seeds in full sun in the garden after the last spring frost. Thin the plants to 10 to 12 inches apart. Blooms should appear eight weeks after sowing. Do not water this plant too frequently though, as it blooms better when kept on the dry side.
How to Grow Moss Rose From Cuttings
Snip about 4 to 5 inches off the top of a stem. Make sure it has a node or at least one row of leaves. Root in water until you can plant the cutting in well-draining soil.
A German legend tells the origin of portulaca: An angel walking through a forest became tired and sat underneath a rose tree to rest. When she awoke, the angel thanked the tree for its hospitality and offered to spread a carpet of moss underneath its branches to keep its roots cool. This moss we now call moss rose.
Native to Mexico, the cosmos is an airy and delicate flower that adds nice texture and color to the summer garden. Once the seedlings are established, they can withstand long periods of heat and drought.
They will also seed themselves, so you'll often find seedlings, both later in the season and the next year.
- Appearance: Cosmos is available in a wide variety of colors like yellow and white, scarlet, pink, rose and red. The leaves are finely dissected, the blossoms daisy-like.
- Size: These plants range from a dwarf form up to 12 inches in height to a bushy 6 feet tall.
- Cultivation: Planting from seed is very easy. Just sow the seeds directly in your garden in the late spring. In 8 to 10 weeks, the blooms will appear. Cosmos need full or half-day sun, and thrive in good, rich garden soil. But if need be, they will adapt to less fertile conditions.
How to Grow Cosmos From Cuttings
Cut blooms when almost open. Leave them in cool water overnight.
The word cosmos comes from the Greek word meaning "ordered universe". The name was given to this plant, because of the simple balance of the blossoms. Spanish priests were said to have grown it in their gardens as a symbol of harmony.
Originally native to South America, petunias are heat and drought tolerant and are a favorite summer bedding plant all over the country. In late spring and summer, you'll find a multitude of types and colors available at garden centers.
- Appearance: The colors are a complete rainbow, including white, pink, lavender, yellow, red, blue and purple, with the options of some being solid and some being variegated. You also have a choice of flower types, with single or double blooms and large or small blooms.
- Size: Petunias grow to about six inches tall before they need to be pinched back.
- Cultivation: Relatively easy to grow from seed, start them indoors 8 to 10 weeks before you set the plants outside. Wait until after all danger of frost has passed and place them in full sun in average soil.
These beautiful flowers have a habit of becoming lanky as the season progresses and do well when trimmed back. Even the ones in your hanging baskets will benefit—looking neater and putting out new shoots—if you prune some of the stems back.
How to Grow Petunias From Cuttings
Clip a 3 to 5 inch section from the top of the plant below a set of mature leaves, making sure to collect soft, flexible examples instead of older, woody types. Defoliate the bottom third of the cutting, dip it in rooting hormone and plant immediately.
Spanish explorers first found petunias growing near the coast of Argentina in the early 16th century. That first species was a low-growing, trailing plant with a fragrant white flower and was not of any particular beauty. The Indians called it petun, or "worthless tobacco". The plant was not thought to be worth sending it back to Spain. Not until breeders in the United States began extensive hybridization, resulting in the miraculous variety of plant types and colors that we see today, did they become popular as a garden flower.
Native to North and South America, sunflowers are extremely heat and drought tolerant. Most sunflowers can easily exist under conditions unsuitable for growing many other garden flowers. They are also very popular as a cut flower.
Children love to watch this bright, beautiful flower grow. They are especially excited when the flower seeds mature, and they are able to eat them as a special treat.
- Appearance: The flowers come in white, bronze, cream and the traditional yellow.
- Size: They can grow from 1 foot to as high as 10 feet tall.
- Cultivation: Sow the seeds outdoors where you want them to grow, and watch in amazement as they shoot for the sky. Shorter strains can handle poorer soil, but the taller varieties need moderately rich soil and regular watering, as well as staking.
It's also worth nothing that these cheerful flowers sometimes seem to sprout in the most unexpected places the year after they are planted.
How to Grow Sunflowers From Cuttings
Snip a 4 to 6 inch softwood cutting from a healthy side shoot, preferably one with mature leaves and no flowers or buds. This is best done in the morning while the flower is not actively in bloom. Defoliate the bottom and plant it in your growing medium.
These towering plants, beacons of light and warmth, have been loved and worshiped for many centuries. The Inca Indians of Peru considered this flower a symbol of the sun and worshiped it accordingly. Priestesses of the temple wore sunflower medallions made of gold.
A tender perennial from the Southwest, this flower is treated as an annual in regions with cold, freezing winters, but it reseeds itself, so you'll always have a supply. Salvia is heat and drought tolerant and blooms prolifically in full-sun gardens.
One of the things I find great about this plant is that it is not an invasive plant. Another thing is that this plant has a very long blooming period, generally lasting from early summer until frost. Blossoms close by midday, but new flowers appear early the next morning.
- Appearance: The three petals of the salvia blossom are gently scalloped and beautifully colored. Hybrids that were developed from two native North American species have resulted in flowers the shade of blue, pink, white and red. The beautiful red spikes of the S. coccinea or "Lady in Red" attract butterflies and make wonderful fresh or dried flowers.
- Size: Given sufficient moisture through the growing season, these plants can reach a height of 30 inches.
- Cultivation: Sow seeds indoors six to eight weeks before setting them out after the danger of frost has passed. Both the annual and perennial forms of salvia need full sun and well-drained soil. But if your area is an especially a hot one, these plants might do a little better with some afternoon shade.
How to Grow Salvia From Cuttings
Clip a 2 to 8 inch stem just below a node. Defoliate the bottom third and place in water, preferably in a location with some sunlight.
The salvia plant, also known as spiderwort, is extremely sensitive to varying levels of pollution and will quickly undergo mutations that change the color of the stamens. Recently it has been discovered that not only is it useful in indicating pollution from pesticides, herbicides, auto exhaust and sulphur dioxide, but it is also extremely sensitive to low levels of radiation.
Children are often attracted to these plants because the flowers don't look like ordinary flowers. The normally large, velvety blooms of crested celosia feel fake even when they are fresh, and they dry beautifully.
To dry them, simply cut them when they are fully open, and hang them upside down in a dark, dry place for a couple of weeks. This plant also makes an outstanding freshly cut flower.
- Appearance: The feathery plumes of C. plumosa and the very full cockscomb-like blooms of C. cristata range in color from cream to pink and red and crimson.
- Size: Dwarf varieties only grow 4 to 6 inches high, but the more vigorous types can reach over 3 feet tall.
- Cultivation: These plants do not like cold, damp weather, and for the best garden performance, grow the plants from seeds started indoors. If you are going to purchase in a nursery, get the green plants whose blooms haven't started yet.
Plant when both the soil and the air have warmed up in late spring. When transplanting seedlings, do not plant them too deeply.
How to Grow Celosia From Cuttings
Though celosia is mostly grown from seed, you can still propagate it in much the same way you would the other annuals on this list. Clip a 4 to 6 inch section, defoliate the bottom, dip it in rooting hormone and plant immediately.
In Elizabethan England, this member of the Amaranth family was called "floramor" or "flower gentle," presumably because it was considered tender and often was only grown in a greenhouse.
Tips to Start Your Annuals Successfully
Healthy, ever-blooming plants will grow better and last longer if you get them off to a good start, delighting you with their blossoms all summer long.
Here are a few tips to help your annuals thrive:
- If you are growing your annuals from seed indoors, keep the soil moist until the seeds have germinated. Don't sow seeds too thickly. Most annuals germinate readily, and you'll just have more work to do in thinning the seedlings to the correct spacing.
- When you buy young plants at the nursery, look for compact, bushy plants that have green foliage. They do not necessarily have to be in bloom, but it's okay if a few buds are showing. Beware of plants with yellowed leaves and plants with long stems that seem to be stretching.
- Don't take a plant out of its pot before you have dug the hole—you don't want the roots to dry out. Tap the plant out of its pot with as much soil as possible still clinging to the roots, and place it into the hole at the same level it was at in the pot. Cover with soil, pat down and water well.
- Water potted plants so they are damp before you take them out and put them in the ground. This will help keep the root ball intact.
- Don't fertilize the plant right away. If you have peat moss and/or fertilizer in the soil already, you won't need to feed them again for a couple of months.
Additional Heat and Drought-Tolerant Annuals
Not minding less than perfect weather conditions, here are some more tough annuals you might want to add to your gardens for a beautiful show of color all summer long.
- Cleome or spider plant: They grow five to six feet tall and reseed with abandon. Flowers are violet, rose and white.
- Globe Amaranth: These are everlasting flowers. If you dry them, they look wonderful in arrangements. Colors include lavender, rose, pink, strawberry and white.
- Begonias (fibrous root or wax): They have green or bronze foliage and pink, rose, white and bi-color flowers.
- Nicotiana or flowering tobacco: These have bursts of tubular, star-shaped blooms above lush foliage. Flower colors range from pink, rose, red, white and lime. These plants can be dwarf or from four to six feet in height.
- Melampodium: These cover the soil with lush green growth dotted with small yellow, daisy-like flowers. They tolerate heat and humidity.
© 2013 Eco-Lhee
MT on June 20, 2019:
Petunias will absolutely not tolerate desert heat from May-September. In climates like Phoenix, Petunias are strictly a winter flower.
Linda on April 02, 2019:
Leave to grow in ground, or cut pot away from roots and plant in ground or larger pot, some are in 30-50 gal. Pots ?
Kristen Howe from Northeast Ohio on June 20, 2015:
Great hub, Eco-Lhee. I've studied some of these plants, a decade ago, when I wanted to be a florist and had botany class. I love sunflowers! Very useful to know some factual tips about them. Voted up!
Thelma Alberts from Germany and Philippines on May 28, 2015:
Seeing these flowers made me missed my garden in the Philippines. Thanks for sharing the informations.
Raimer Gel on July 10, 2014:
I wonder if there are also annuals that love the wet climate. I live in the tropics.
Stephanie from Canada on March 16, 2013:
Lots of good info! We might be moving to Alberta next year...so I'll have to come back and check out this list again.
Eco-Lhee (author) from Alberta, Canada on March 15, 2013:
Dirt Farmer - Thank you! and Radcliff - You should have a beautiful, colorful garden this year, glad you enjoyed! Grab some pictures!
Liz Davis from Hudson, FL on March 15, 2013:
Thanks for giving me some ideas for this spring! Those periwinkles spread like wildfire down here in Florida. The zinnia also grow especially well in my area.
Jill Spencer from United States on March 15, 2013:
Like your choices! Shared & pinned. (:
Eco-Lhee (author) from Alberta, Canada on March 15, 2013:
Thank you! I'm in Alberta and we don't get the hot, but the wind sure makes it dry so these are great flowers for me!
Diana Uzzell from Dayton, NV on March 14, 2013:
What a great article. I live in Nevada and that's us, hot and dry during the summer!!!