Cosmos are the annual gifts that keep on giving. And that’s good, because they’re one of the easiest flowers to grow and they come in a huge range of colors, bloom types and varieties.
Cosmos (Cosmos bipinnatus) plants are part of the Aster family, and native to Mexico and some areas of the desert Southwest. Between this classic cosmos and the related sulphur cosmos (C. sulphureus), the flowers can grow in nearly a full range of growing zones – from zone 1 through zone 11.
Of course, in nearly all but the hottest of these zones, cosmos grows as an annual and dies back with frost. But if you think that is a good reason to avoid growing the plant, I’d like to convince you otherwise. Cosmos is a prolific re-seeder in even the poorest of garden soils.
Add Color and Wildlife
Cosmos flowers attract butterflies and hummingbirds, along with other insects. They will bloom from mid-summer through early or mid-fall, depending on your first frost date. You can cut flowers for indoor arrangements, which also can lead to more blooms. I also leave plenty of dying flowers on the stems because they feed finches. I love watching a finch land on the small, swinging branches to peck away at the seeds. In a world in which so many flowers are yellow, it’s so great to enjoy the white, pink and red tones of cosmos in my xeric garden.
Plant from Seeds
You can plant cosmos from seeds or nursery transplants. I have had mixed luck growing cosmos from seed until this year. I know the flower seeds like loose soils, but with our dry and windy conditions, I found it better to cover the seeds lightly with some compost and water with a soaker hose to prevent washing away.
As for planting again next year, unless you severely disturb the soil where (and near where) you had cosmos last year, you should get plenty of volunteers as soon as summer rains start, and see the seedlings with their fine leaves growing taller as monsoon rains continue. You can help Mother Nature by gently spraying the area where you want the flowers to appear if early-summer rains have been light.
Most cosmos varieties grow tall, maturing at up to four-feet high, so they often work best at the back of a garden. If you have a bed or meadow filled with cosmos, they tend to support each other and seldom flop over as some plants can when they get tall. Cosmos loves full sun or part shade.
Sit back and enjoy
Once they become seedlings, cosmos do best with nothing but rain water. Overwatering the plants actually can lead to fewer blooms.
There are some areas of the United States that consider cosmos invasive, including a few spots in western New Mexico. And I admit one of the best characteristics of the plant – easy re-seeding – also can mean it pops up where we don’t want it. For example, if I didn’t pull seedlings out of our steps, we would not be able to walk down to the garden. But I leave a few off to the side for compromise. I pull those that block other plants and let the rest grow as they may. They’re crowded, but I love the effect.
You can grow cosmos and enjoy cutting the flowers for indoor arrangements. And have even more fun watching for new flowers to begin popping up the next summer!
In this dry year, I feel like our plants are under a triple threat from drought, strong winds and unusual heat for this early in summer. I’ve decided the drought and lack of plant growth on our land and the forest near us has caused insects and larger critters to eat more (and different) plants than usual because they’re hungry or thirsty.
At any rate, we’re spending way more time watering, covering or doing damage control than we’ve ever had to do in previous years. Here are a few plant attackers and some ideas for fighting them:
Drought. The first protection is to choose native drought-tolerant plants. A few of ours, namely the santolinas and Datura (jimson weed) have thrived despite no supplemental watering. For the first time in five years, we’re having to water other plants in our rock garden typically immune to short periods of drought. And the rain barrel is running low.
As with ornamental plants, water edibles like tomatoes early in the day and in consistent amounts. They shouldn’t remain wet, but a little moisture in the soil helps them fight dry, windy and hot conditions. Mulching around as many plants as you can (save a few that don’t like wet roots, such as lavender and rosemary) can help them stay damp longer. Finally, remember plants recently moved or planted after purchasing from a nursery need extra water during dry, hot conditions their first year or so.
Heat. Mulching also cools the ground above a plant’s roots, helping the plant get through blazing heat. Sometimes watering is all you can do to protect a plant in record heat. But if the plant is in a container, scoot it into an area that’s slightly shadier or has shade during the time of day when your heat typically peaks. We have been covering our tomato plants with shade cloth this year soon after temperatures soar above 90 degrees. In the past, we’ve had problems with blossoms and fruit set when temperatures soared. Prevention also helps for heat. It’s wise to plant as close as possible to the recommended date for your area. This year, we were traveling and planted later than normal, so our plants had less time to toughen up before heat struck and we paid for that.
Insects. Some plants are just more susceptible to insects than others. And when it’s this hot and dry, all plants are more vulnerable to bugs and the diseases they can transmit. Keeping an eye on your plants, even with a stroll through your yard or garden after dinner, can help you spot problems. Keeping plants watered and free of as much stress as possible also helps.
Others, like basil, are favorites of lots of insects. Since the leaves the insects attack are the part of the plant we eat, I keep my basil covered with a light row cover cloth that lets in air, sunlight and some water, but keeps out as many leaf eaters as possible.
Other critters. The tender leaves and ground-level placement of seedlings are also more vulnerable to attack. I’ve seen the leaves of new cucumbers or flowers decimated by grasshoppers and more often, by snails. The slimy acrobats even climb up into containers and eat plants as soon as they come up. We use egg shells as the best deterrent we can find, but there also are snail baits for bad infestations.
Below-ground fencing can deter gophers and other underground tunnelers, but that requires fencing a few feet underground around all plants. We reserve that fun task for our vegetable garden only. Then, despite those efforts, a squirrel has come through the fence and made giant holes in our garden. He has not damaged any plants yet, but I have a feeling it’s coming. We have had some luck spraying Animal Stopper small animal repellent around some plants to deter squirrels.
Our deer are grazing much longer into summer this year and have destroyed all the bloom stalks on our native and hybrid roses. You have to be pretty desperate to eat something that thorny on a regular basis. We’ve had some luck with Animal Stopper deer spray, but the only way to ensure deer stay off plants is to fence them out.
Look to your neighbors, master gardeners and landscapers for more local strategies to help you keep plants alive during rough patches. And practice patience.
When water is as scarce as it always seems to be in New Mexico, especially this year, I appreciate all of the native and drought-tolerant plants that hang in there until rains finally arrive. After all, it’s the smart and right thing to do here in the Southwest: grow plants that need little to no watering from our wells and taps.
And we follow those principles, doing what we can to save water. Still, I love some plants too much to give them up completely, and I imagine that’s true of many people who move to our dry state. I would hate for any gardener to feel badly for having a few guilty pleasures from the plant world. Here are some strategies for finding the middle ground between gardening sustainably and growing plants you love.
Plant high-water users only as occasional fillers and in moderation. By high-water plant, I mean not xeric, or needing some supplemental watering. If a plant doesn’t meet the soil, sun exposure and watering requirements, you’re unlikely to have much success and will have to resort to photographs from botanical gardens!
Fill in color with a few annuals. I fill a few patio containers each year with an annual or two or pop a few annuals between xeric plants that flower for only part of the season.
Grow a few houseplants you love. Geraniums are a favorite of mine, and I don’t have to give them much water in the winter while they survive inside near a sunny window. My new guilty pleasure is violets, although they stay inside all year. Growing orchids, violets and other houseplants more suited to tropical climates can be a guilty pleasure without adding much to water usage. Of course, that’s assuming you stick to a few plants only … if you can.
Create conditions that help the plant survive with less water. Use mulch, shading or other exposure strategies and careful timing with monsoon rain to help a nonxeric plant make it through hot, dry periods. And accept that your plant might not bloom as much as it would in a wetter climate by enjoying the blooms you get.
Choose plants you love that are useful to “waste” less water. If you’re growing food for your family (and not wasting lots of harvest), you’re replacing some of the water that might have been used to grow the same food on a large farm, and doing so locally. Plus, the benefits outweigh a little bump in water use and cost. Or grow some cut flowers you love instead of buying them in a store for your home or family and friends. Finally, some flowering plants that require a little more water provide food for hummingbirds, bees and butterflies. Although natives are better, adding a few flowering plants not native to your area can help pollinators.
And finally — use rain barrels to water your lovelies during dry weeks.
One of the best features of many xeric gardens is the natural look of the landscapes. We often use rocks and boulders and tuck native plants among them. This design most closely mimics the look of the landscape around us.
If you’ve moved to New Mexico and other Southwestern states from areas of the East and Southeast, you might be more used to a cottage garden look, where shrubs like boxwoods form hedges and foundation plantings repeat the same flower.
On a recent trip to Austin, I noticed a perfect blend of both features. Many of the gardens I toured with fellow garden bloggers struck me with how well they used repetition in their designs. But these Texas gardens also had a natural look. Here’s a photo essay from Austin, along with a few New Mexico shots.
So, Why Repeat Plants or Containers?
I realized we tend to favor single plantings in our gardens, typically choosing a plant based on how it will look in a location or complement a nearby plant. And when you love plants, it’s tough to resist adding any you like to any garden you own. But after seeing the use of repetition, I decided we need to add more repetitive elements. Here are a few reasons why:
Continuity. A garden is a sort of composition, and repeating an element gives it a sense of balance without making it look too symmetrical or monotonous.
Easier maintenance. We all have a plant we’ve tried that survived despite strange weather or a little neglect. Others require little to no pruning or deadheading. Why not scatter a few more of these easy-care plants around your home?
Color. Although many xeric plants are colorful, some really stand out in the garden. Using the same purple in a row of plants or throughout a garden gives a color focal point.
Saving money. Sure, you still have to buy the plants, but it is less expensive to buy four of the same perennial once than to fill in an empty space in the garden each year.
Finally, I would say that repeating plants is a fine example of xeriscaping principles. When you plant 5 native grasses in a grouping, they all have the same water and sun exposure needs. You don’t have to come in and add water for a plant that needs more than the grasses or take the chance of overwatering and killing a nearby plant. And when you use repetitious art or hardscape elements, you add to the design without adding plants — and that requires no water at all!
There really is no true blue in garden leaves or flowers, but many blooms come close. Iris, blue cornflower and blue flax come to mind. And there are plenty of violet flowers that have a similar “cool” effect and contrast so nicely with oranges and yellows.
But you don’t need blue flowers to add touches of calm blue to your garden design. I saw this firsthand on my recent tours of Austin gardens with the Garden Bloggers Fling. Here are some of my favorites:
Plus, garden art requires no watering or maintenance. Paint is especially inexpensive. It just couldn’t be simpler to add pops of color to your patio, deck or garden.
Special thanks to the wonderful garden bloggers and gardeners of Austin for your hospitality. What a great time!
Santolina is an herb said to be used in folk medicine to make a tea that expelled intestinal worms or was used as an eye wash. The plant repels insects, and placing leaves in sachets is said to repel moths.
We grow santolina (also known as lavender cotton) in our rock garden for its evergreen appearance, yellow button-like flowers and drought tolerance. It’s not native to North America, but does very well in our dry Southwest soil.
Gray santolina (Santolina chamaecyparissus) produces bright yellow flowers in summer. The plant has few matches for attractive gray-green foliage and its ability to spread as a groundcover. Our large one has been a cover for a litter of cottontails and is now spreading slowly over a rock wall.
Another variety, green santolina (S. virens or S. rosmarinifolia) has lemon-colored button flowers that contrast with its deeper green foliage. Both types of santolina have an aroma, and some people find the bloom aroma offensive. Most varieties of the shrubby groundcover grow in zones 5 through 9 and need only moderate water. Learn more about santolina varieties from Cornell University.
Caring for Santolina Plants
The plants prefer full sun, but our largest santolina blooms each summer even though it now gets lots of afternoon shade from a nearby tree. Place the plant in well-draining soil. When temperatures reach 90 degrees, water your santolina every few weeks if you get no rain. Otherwise, it needs water only monthly or less.
Prune (really, shear) santolina shrubs in early spring to shape and remove dead flower stems. Every two to three years, give the plant a harder prune down to about 6 inches above the ground to keep the plant from getting leggy. You also can sheer dying flower stalks after the first bloom for the chance of a second summer flowering.
The plant is evergreen or semi-evergreen in some climates. Santolina does best with no fertilizing. How easy is that? And you can take cuttings or divide larger portions of the plant in fall, although the transplants might succumb to cold, so if you can warm them the first winter, even better.
Whether you grow santolina for its herbal properties or appearance, you can grow that!
One of your houseplants or outdoor plants looks funky and you think something might be wrong with it. Your automatic response? Add water. Sometimes, that’s the best solution, and sometimes it’s just a waste of water, and maybe of your plant.
Wilt is a classic example of the dilemma gardeners face; wilting can be caused by both underwatering and overwatering. What’s more, factors other than water can cause leaves to wilt, even though the roots have plenty of moisture.
Here’s the thing: If too much water surrounds your roots, or they never have a chance to dry a little, the roots don’t get enough oxygen, which also is crucial for plant health. Further, some plants are susceptible to root rot. Let’s look at a few reasons to add water to help a plant, along with a few tips on when not to water.
How to Avoid Overwatering
Regularly check and maintain all sprinkler, bubbler and drip systems. Redirect flow amount or direction for any that appear to be getting too much water, and repair leaks.
The problem might not be how much water, but how you water. Many plants take poorly to regular watering of their foliage. Water that sprays evaporates faster (which is more wasteful) or can sit on foliage too long, leading to diseases. Spray irrigation also waters too much ground around a plant, helping weeds more than your shrub. On a sunny day, most of the water evaporates, but if you water late in the afternoon, on a cool, cloudy day or onto a thick or crowded plant, the water sits overnight on leaves. The best times to water overhead are to wash off dust that builds up on leaves (affecting photosynthesis) or to wash off aphids. But reserve these actions for sunny mornings whenever possible.
The soil is your best test for whether a plant needs water, not the plant. Check the soil around a houseplant or outdoor plant to see if it still is damp one to two inches below the surface. You can use your finger, a small trowel to gently push soil aside so you can see or feel it, or small tools like chopsticks of pencils pushed in and then removed to see if soil or moisture have stuck to the wood. There also are commercial soil monitoring tools available.
Mind the season. When plants go dormant in winter, they need much less water. You should adjust your schedule accordingly and try to avoid watering too soon in spring or too late in fall.
Have a way to stop automatic watering when it rains. Weather sensors are available for irrigation and rain-harvesting systems, and others have smartphone software. This helps you pause a watering schedule from work on a rainy day, for example. Although these systems are designed mostly to conserve water, they also prevent oversoaking plants. You can even get solar-powered sensors for watering with rain barrels. I reviewed one last year.
Water slowly, which is another drip irrigation advantage. The more slowly the water falls to the ground, the more gradually it penetrates. This is especially important for containers; fast, hard flows of water can wash potting soil nutrients right out the container’s drain.
When to Water
Always water new plants, seeds or transplants more often in the first year or so. Even though they are labeled xeric or low-water use, the roots need help growing in their new environment and the plant is more vulnerable.
On hot, sunny days. If you haven’t watered in a while and it’s peak summer heat, give plants with mostly dry soil, especially those most vulnerable to heat, a drink in the morning to help them get through the day.
Consistently for vegetables and edibles. It helps a tomato to nearly dry out some between waterings, but not to completely dry. Watering the same amount each time keeps the plant growing at a healthier rate and prevents fruit problems such as splitting.
Xeric plants are smart, easy-care choices simply because they need little watering once established. Still, I’m sure some people avoid trying new plants, or opt for mostly gravel, to lessen time needed caring for ornamental plants.
I’ve got five great options for Southwest gardeners, each hardy in our zone 6B garden and during summer heat. Although all are not technically xeric, they can thrive with little to no watering other than rain. Mostly, these plants need very little care, so try something new this year!
Yarrow (Achillea sp). Yarrow is an herb, and a close relative of chamomile. Yarrow is said to aid digestion or heal wounds when applied as a pulp. Take a look at the scientific name (ever heard of Achilles and his heel?) and you can see how many years people have used yarrow for medicinal purposes. Achilles is said to have applied yarrow tinctures to heal and prevent wounds.
I grow yarrow because it’s pretty, attracts pollinators, and is one of the easiest perennials to maintain. Technically, yarrow needs a little more water than other low-water plants when summer temperatures hover at 90 degrees and higher, but our plants have made it through many seasons with one spring watering and natural rain after that. They’re hardy in zones 5 through 8. You can cut the spent blooms off to encourage more flowering. But for easy care, leave them on the plant, especially in cooler regions. or cut them back all at once for a second bloom in warmer climates. When trimming, you’ll probably see some tiny flowers close to the leaves that should shoot up and open. We’ve transplanted several yarrow plants with no trouble.
In windy areas, ornamental grasses stun in the garden. We often place them as single plants in a grouping of others, but I love the look of a row or grouping of the same grass in the landscape. Even those that aren’t native tend to need less water than some plants, since they don’t truly flower, but can produce lovely stalks topped with seeds. And you can mix textures, colors and heights for landscape interest. There are so many choices!
Even those grasses that aren’t native need little care and use little water. A few (like Silky threadgrass) can spread, but you only need to pull or dig up the tiny starts in early spring to control where they grow. We like to add one annual such as Purple Fountain Grass (Pennisetum secateum ‘Rubrum’) each year for color pop, but our other grasses make it through winter.
Just check to see average zones. For example, the Purple Fountain Grass can overwinter in zones 8 through 11. And ask whether your favorite is a warm-season or cool-season grass; that helps you know when to plant it and whether it will survive winter or need a little shade in the heat of summer. All you have to do is shear back the foliage each spring as the grass begins to green at the base. So, so easy.
Prairie or desert zinnia (Zinnia grandiflora), is an easy and attractive groundcover with sunny yellow flowers that grows in zones 4 through 9. The plant is native to New Mexico, Arizona and parts of southern Colorado, so it’s hardy in Southwestern soils and survives drought. Ours were already in our garden, and I have heard that the plant can be a little challenging to get started. My guess is excited gardeners plant the zinnias too soon, before soils have warmed. Ours cascade down a rock wall, coming up each year in little soil, but plenty of warmth from the rocks. The rocky soil also drains well, which likely helps keep the plants healthy and spreading at just the right rate (not invasive). The foliage browns in winter, but is so small it doesn’t look messy. All I do each year is put on my gloves and gently pull away the dead foliage when I see it greening up at the bottom. Once you do that, the plants get the sun they need and begin growing and flowering.
Gopher spurges (Euphorbia rigida) are among few plants that handle extreme cold (down to -20 degrees) and the high heat of zone 11. The plant is called gopher spurge because it has been said to repeal gophers, but I’m not sure there is any proof of that, or anything at all that truly repels the underground destroyers. I can say that ours have survived, save some deer chomping. The stalks that were eaten succumbed to cold, but I just cut them off at the base of the plant.
Otherwise, our gopher spurge has grown nearly a foot in one year and was among the earliest flowering plants in our spring garden. We also have a Euphorbia ‘Ascot Rainbow’ we bought locally last year, and the foliage alone is beautiful. This newer plant also has survived winter and is beginning to bud out. All you have to do is cut off stems after the seeds ripen; new stalks will come up and you can enjoy the silver-green or colorful rainbow foliage all year. Gopher spurge and many other Euphorbias are succulents, so they’re lovers of sun, heat and low water.
It’s the year of the Coreopsis! And I’m so glad. The native flowering plant is so versatile. It looks beautiful in rock gardens or more formal landscapes. Just place coreopsis in well-draining soil and most perennial varieties should be hardy from zones 4 through 9. Sometimes called tickseed, coreopsis comes in several varieties and deer seem to ignore the plants. Because the native plants tend to come up along ditch banks or other disturbed areas they tend to easily grow in any Southwest garden conditions. The bright yellow blooms of Lanceleaf and Grandiflora coreopsis are common, and breeders have grown new varieties of Coreopsis with color variations.
Deadheading flowers as they dry up will keep them blooming, but if you find deadheading takes too much time, wait until a good flush of blooms has begun to die back and shear the flower stalks off all at once; you should get more blooms.
My husband’s got worms and I couldn’t be more thrilled. Because his worms eat food scraps and produce a nectar-like waste product – worm castings.
With vermicomposting, he’s producing a soil amendment (humus) full of more than 60 micronutrients and trace minerals to gently and naturally support plant growth. Worm castings are the excrement left by worms, and the worm tower he uses for vermicomposting makes it easy to feed the worms and harvest their castings.
Benefits of Worm Castings
Castings hold all sorts of live micronutrients that help plants better absorb nutrients from soil, especially soil with low or high pH.
The worm castings can help repel some pests such as white flies and aphids; an enzyme in the castings is offensive to pests.
Feeding worms food scraps reduces and recycles garbage throughout the year.
Worm castings do not stink!
How a Worm Bin Works
Tim purchased a Worm Factory from Nature’s Footprint a few years ago. He keeps it in a corner of the garage for easy access and protection. Vermicomposting works with upward migration. The worms move up to eat, and gravity sends moisture and castings to the bottom. Adding food at the top every so often (when worms are actively eating the last food you added and are moving to the top tray) keeps the worms continuously fed and reproducing. The worms eat paper, fruit and vegetable scraps, bread, coffee grounds and eggshells, along with other scraps. The bedding added to each level eventually breaks down into castings as well.
The resulting compost is thick, dark and crumbly. Its ready to use as soon as you harvest. Some of the best uses are to mix the castings in with garden soil as an amendment or to top dress container plants. We added castings to some of our vegetable starts last year a few weeks after planting, just loosely scratching the castings into the soil around the plants. It takes less worm compost to improve soil than regular compost. Finally, use worm castings to make compost tea.
A Few Tips
Keep the tower warm in winter. You might have to either move a worm bin or give it some heat. There are insulators made for bins. Tim hangs a lamp over the bin and sets a timer so the lamp warms the bin at night. Even if production slows, the worms are warm enough, and the food does not freeze.
You’ll have more success if you break the food scraps into manageable sizes, about the size you get when running a peeler over a carrot.
Be sure to check instructions for worm type. Red wigglers (Elsenia festida) eat and reproduce better than most, but you can use European nightcrawlers (E. Hortensis), which work well in our tower.
Store your worm castings in an airtight container and they’ll continue to break down. Just let the castings dry a little before sealing. They can be damp but not wet.
The leachate, or liquid that runs down, can be toxic. Don‘t use it if it smells bad or on edibles. Be sure to dilute it with a ratio of about 10 parts water to one part leachate.
If you’re looking for a way to get kids involved in gardening, worms are it! What fun kids can have helping care for the worms and seeing how they help a family grow food or pretty flowers for mom. It’s also a great way to teach responsibility if kids are charged with prepping scraps or bedding and feeding worms.
If you can’t spend the money on a worm bin or tower, you can find information on making your own or vermicomposting directly into a garden bed.
I just discovered this delicate, early bloomer in the past few years when friends suggested Love-in-a-Mist (Nigella damascene) seeds from our local iris farm. The foliage looks much like fennel or dill as seedlings sprout, and nigella also is called fennel flower.
Nigella Is Versatile
We grew multicolored love in a mist in our rock garden. Tim threw the seeds out in fall and by mid-spring, we had fine fern-like leaves popping up from between the rocks. Although Nigella does best in damp sandy soil, ours grew out from under rocks that make up the walls of our xeric garden. The rocks likely held moisture longer than a spot in the open might have. The rocks also trapped the tiny seeds so fewer blew away. Plus, nigella can tolerate dry conditions.
But then we tried another approach – we bought a packet of Bridal Veil (Heirloom White Nigella) seeds from Renee’s Garden and sowed them in early summer in a blank spot of our vegetable garden. This soil is far better in quality, and the seeds received consistent drip watering. The flowers were taller and stunningly white, with maroon to black centers. The plants reproduce from seeds, assuming some seedheads are left on plants at the end of the season.
Sow in Fall or Spring
Although most instructions for growing nigella say to sow in spring, you can sow them in fall in areas with mild winters. They need full sun and grow in zones 2 through 10. That worked well for us last year, but this winter has been dry and consistently colder, so I’m anxious to see how many reseeded in our gardens. The bridal veil flowers in our vegetable garden bloomed later in the year, but were planted later. Sowing the seeds a few weeks apart in spring and fall can help ensure constant blooming of nigella in summer.
Use as a Cut Flower
You can cut nigella blooms for flower arrangements, and even better, cut some of the seedheads. If you cut the flowers to enjoy indoors, leave a few blossoms on the plant so they can dry and drop seeds for the next year. If you get too many, thin them out while small. Enjoy the seedheads after flowering by cutting their stems just after flowers fade, and hang them upside down away from direct sun.
Nigella is easy to grow and a great addition to any xeric garden!