Roses are red for Valentine’s Day, but there are other plants, including houseplants, bulbs and a few xeric plants that make great Valentine’s Day gifts with their deep red blooms.
Here are my favorites:
This xeric salvia (Salvia gregii) is a garden stunner. Add one to your rock garden for all-season color in most regions of the Southwest (zones 6 through 10). Hot lips sage is a perfect plant for lovers with bright red and white blooms.
Red or Iceland poppies are perfect flowers for pressing and can last a bit as a cut flower. Papaver rhoeas (Red or Shirley Poppy) is a gorgeous complement to other flowers in the garden or planted in a bunch for a bright red meadow.
Geraniums come with deep maroon red, fire engine red or pink flowers. Plant a red geranium and a white geranium in a container for your Valentine. These plants can stay outside in spring or summer in most areas of the Southwest will continue to bloom inside in winter if left in a sunny window. I like to cut the bloom stalk near where the flowers begin and float it in a clear glass container filled with water.
If the symmetrical rosettes of leaves topped by pretty flowers are not enough (and they should be) to brighten any home or heart, the plant names might do the trick. There are thousands of varieties of African violets hybridized by pros and amateurs with fun registered names. Hybridizers name the violets after loved ones, hobbies and the plant characteristics. There are plenty of varieties with pink and reddish flowers (not just purple ones) .
Many varieties of the winter-blooming bulb come in solid red or white with red or coral streaks. Although most are raised to bloom around the holidays, they can bloom later if dormant and dark for a while, or have a second bloom. I have one that bloomed like crazy in December but has another bud coming up that likely will open just after Valentine’s Day.
Although cut flowers are nice, a plant that can grow on in your garden or home makes a perfect gift for your Valentine. Tulips open outdoors in early spring, and even Claret cup cacti have gorgeous red blooms. My all-time favorite cutting flower is the gladiola and a nice guilty pleasure in an otherwise low-water garden (and protected from munching deer). Or try giving your loved one an anthurium, the tropical plant with a red heart-shaped flower!
Succulents, and especially cactus plants, usually prefer heat and drought. That’s one reason they make such perfect plants for desert gardens. But in the high deserts or mountains of New Mexico and other Southwestern states, many cacti only can live outdoors in the summer. Enter containers…
Why Plant Cacti in Containers?
The best reason for planting cacti in containers is the flexibility it offers. You can move the plant throughout the year (carefully) to bring it outdoors when summer nights warm and indoors as frost approaches. But you also can move your cacti around to control temperature or sun exposure. Even succulents can burn from intense sun, so it is good to keep an eye on the plants and rotate or move them depending on sun, including sun from a south- or west-facing windows.
Another reason to plant cacti in containers is to isolate watering. When planted outside, especially near drip or other watering systems, cacti can get too much water. With containers, you can control cactus watering based on season and when the plant goes dormant. If you love the look of a cactus in your desert landscape, nothing says it has to be in the ground! If the water or temperature conditions are not ideal, place your cactus outside in a colorful container. Just remember – the outdoor container should have good drainage and can cool off more at night, so don’t leave a container cactus outdoors in winter unless it is hardy to at least 10 degrees cooler than your lowest low.
Finally, most cacti are slow growers, so you don’t’ have to repot them often. Other cacti spread out of control in the garden. You’ve probably seen a xeric yard in your neighborhood with prickly pear growing like a sprawling hedge, maybe onto the sidewalk. It is easier to control cacti when in the confines of a container.
Container Cactus Mix
Planting and caring for cacti in containers is easy, but the soil mix is crucial to success. If you plant a cactus in standard container potting mix, which is designed to help retain water, your cactus roots will get soggy and rot. You can buy special cactus mixes or make your own. Ask friends or local experts for ideas. Examples include adding 1 part coarse sand and 5 parts perlite (for airflow and drainage) to 4 parts of potting mix. Vermiculite also improves aeration but holds too much water. You also can add a little bit of rock dust or pumice to your mix.
Handle your cactus carefully while transplanting. You can use an old sock or towel to wrap around the plant near the base and lift it out of the pot. Or turn the pot with the cactus on its side, resting the plant on an old pillow (that you won’t use again) to cushion the plant while you pull the container off the root ball.
Old long-handled barbecue tongs are great tools for holding a cactus while you place it in its new container; or use regular tongs for smaller plants. The eraser side of a pencil works great for gently pressing soil down around smaller cacti.
Some Favorite Container Cacti
Some of these cacti are spinier than others, so you might want to be careful where you place them. Many will flower, especially in spring or early summer. And some can tolerate pretty cold temperatures, but still would be fun winter houseplants.
Barrel cactus (Echinocactus grusonii). The golden barrel and other barrel cacti are such great landscape plants, giving a pretty round shape to landscape designs. I especially love them on hills. But they’re only hardy to 15 to 17 degrees, so we keep ours in a container.
Pencil cholla (Cylindropuntia leptocaulis). Pencil cholla are pretty scary looking, with spines up to one inch long sticking out from tall, thin branches. They are hardy to -20 degrees and love heat, but spread easily in the yard.
Bishops cap (Astrophytum myriostigma). This is an attractive and slow-growing cactus perfect for a container, especially since it only can handle cold down to 20 degrees. I love the sort of grainy white and green look of the plant. See the second photo above. That is a bishops cap in the middle.
Hedgehog cacti (Echinocereus). It’s native to the U.S. and Engelmanns hedgehog is most common throughout the Southwest. It’s spiny, but should produce bright pink flowers more than two inches across. The plant only reaches about 10 inches in height.
Fence post (Pachycereus maginatus). This is a columnar, almost regal cactus. The columns have ridges with small spines and when planted in a row, they form an excellent wall. Columnar cacti are great choices for planting in containers of homes with high ceilings or to simply provide height behind a grouping of houseplants. They just need plenty of filtered sun.
Ocotillo (Fouquieria splendens). It’s hard to imagine this sprawling cactus in a container, but it can be done. It will need summer heat and can survive temperatures down to 20 below freezing. So, the garden can work, but you can control ocotillo growth in a container and enjoy it as a rising backdrop to other cacti or succulents.
Old man cactus (Cephalocereus senilis). This is by far one of my favorite cacti. But it needs to stay in temperatures above 46 degrees, despite its shaggy layer of “hair.” This is another slow grower, and often a conversation starter in a home!
Spineless prickly pear (Opuntia canacapa). For the look of a gorgeous green and juicy cactus pad and no spines, go with this pretty plant. It still will grow new pads, but you can cut them off or plant them elsewhere. Both regular and hardy prickly pears can survive temperatures down to zero.
In the arid Southwest, most plants don’t like an abundance of rainfall. Xeric plants such as lavender or rosemary can be damaged or die from too much moisture in the crown or roots. Sometimes, the location a homeowner places a plant affects watering and alters the plant’s ability to thrive as as it should for the zone in which the gardener lives.
Other times, conditions change. That’s what happened in an area near the foundation of our home when we expanded our back patio. We found that excess water from the patio and rain barrel near the edge redirected water during rains. During monsoon season, a blue mist spirea (Cayopteris) and cotoneaster began to show signs of overwatering.
We needed to divert some water away from the two bushes and recognized the importance of either collecting or directing rainfall. We couldn’t afford a large rain cistern, but we had one natural resource in abundance—rocks. So we built a dry river bed, also called a dry creek bed or dry stream. The project was a way to change up the landscape and divert extra water down to our lawn.
Step 1: Move plants
The first step in our project was to move the plants. We divided the spirea and kept the largest portion to replant; we transplanted two smaller sections on a ditch bank back in our orchard. We ended up removing the cotoneaster, which was beginning to overgrow a path we us regularly and had large areas of rusted, dying foliage.
Step 2: Design hills and valleys; test
We next built up a small hill or berm as a new spot for the blue mist spirea and a new cotoneaster bush. This would allow us to control the plants’ watering better. We dug and scraped a river-like trough to help water drain down and toward the grass. It didn’t take much depth to get water from the patio to the grassy area below. Getting the depth and flow right took some trial and error with a garden hose to simulate the rain and made a few adjustments where water backed up.
Step 3: Add rocks
We already had a pile or two of rocks we’ve dug up. And there is no shortage around here. The first step was to cut and lay down black weed barrier, followed by large rocks along the top and side of the dry river to hold the fabric, direct water and add a decorative, but natural effect. This was followed by addition of medium and smaller rocks. We gathered the small rocks throughout fall and winter, sometimes a few at a time, to fill in.
Step 4: Plant!
All our hard work was rewarded with a new area for planting. We had the two bushes, and moved a small pine leaf penstemon to a lower part of the berm. We purchased several grasses, some perennials and a few annuals to fill in. Then we got lucky and had a volunteer blanket flower crop up in just the right spot. We stopped the rock design a foot or more from the house in most spots and used pecan mulch around those plants. Here’s why: Rocks reflect sun and heat and my office window is right above the dry river bed area.
Pulling out the large cotoneaster and adding rocks has intensified the heat in my office. I know that will ease once the plants grow to maturity. And the heat might be welcome on a cloudy January day. We also lost the first cotoneaster planted. It could have been any of a number of causes, but we likely made a common mistake: not watering enough. I was so concerned with keeping this plant from getting too much water that I failed to account for how much would drain away from its roots and the immaturity of the plant. Our second attempt is going well. It’s also easy to change the flow of water just by placing a rock or two in a certain way. So we check the flow when it rains to look for pooling of water.
Overall, we were pleased with the look and function of the dry river bed. The native grass below it turned green earlier than normal and we stopped problems from mud and overwatering of bushes in the area. This is an easy and inexpensive garden DIY project!
No matter where the current drought monitor stands, New Mexicans and other Southwest gardeners know that water is precious. Luckily, plenty of native plants have adapted to the dry conditions of desert and intermountain regions of the Southwest.
Still, gardening responsibly anywhere demands attention to water use and waste. And people who want to grow food in their yards or on their patios can save water and money with sensible, waterwise strategies.
The good news is that the home and garden market keeps pumping out new tools to help gardeners conserve water but enjoy their landscapes. I’ve recently reviewed two products for Gardening Products Review. One of the products combines solar technology with rain or faucet water to support slow drip systems in areas of the garden.
The other product from a small startup company helps you water deeply near the roots of plants using a simple garden hose. Up next: I’m testing a cloud-based system to control watering from your faucet.
Check out these watering product reviews, along with lots of other reviews from fellow garden writers at Gardening Products Review’s website. And plan now for next spring’s waterwise plantings.
Growing with organic methods is smart for lots of reasons, both personal and environmental. Although there are plenty of strategies gardeners and homeowners can use to save water with ornamentals, such as planting native and xeric plants, it’s a little tougher with vegetable gardening.
Tomatoes, for example, need consistent watering! But growing tomatoes organically can conserve water. Here are five ways how:
Organic soil retains water better. Anyone can improve their soil’s water retention by up to 5 percent by adding organic matter. It also helps to avoid use of chemicals and pesticides. Using pesticides and chemical fertilizers in gardens can throw off the natural balance of the soil, making it less able to retain moisture around plant roots and making fewer nutrients available for plants. On the contrary, planting cover crops in the fall and use of compost or other organic matter help restore valuable soil nutrients. Organic matter also helps soil structure for water infiltration and retention. Healthy soil can respond better to drought conditions.
Organic growing protects water supplies. By avoiding chemical pesticides and fertilizers, gardeners also protect the water supply. Pesticide chemicals can remain in the soil for years; some are more toxic than others and break down in the soil more slowly. The chemicals from these products can run off into bodies of water, such as rivers. And eventually, they can seep into groundwater. That might seem a distant concern to some urban gardeners, but those of us using wells live right above available water. The more chemicals that run into water supplies, the less safe drinking water is available.
Use of mulch reduces evaporation. A layer of appropriate mulch above the ground around a plant helps reduce ground-to-air evaporation, making the soil take longer to dry out. The mulch also helps cools plant roots. Using organic mulches such as bark, nut shells, compost and others adds organic matter to the soil slowly over time for an added bonus.
Organic methods can minimize erosion. Traditional gardening and farming uses rototilling and deep plowing to turn the soil before each growing season. Plowing deeply and turning the soil over can disrupt soil microorganisms, harm soil health, and place looser soils on top, where they’re subject to erosion from water and wind (think Dust Bowl). No-till methods help control erosion and build soil structure. The soils, in turn, better retain water. This can be a problem if the soil drains poorly, but a definite help in low-water regions. Not tilling involves building up beds with organic matter, much like nature does as plants drop leaves that decompose. If you want to work organic matter in, it’s best to grab a shovel. A broadfork is the best tool for breaking up compacted soil.
Growing organically creates healthier plants. Healthy soil is the foundation needed to grow healthy food. When soil has good nutrients and structure, it supports root growth and uptake of nutrients, improving plant health. Plants that are not healthy are more vulnerable to insect and disease damage. The plant might not use water as it should when it’s stressed, and the gardener certainly guesses that if a plant looks bad, it needs water. So, keeping plants healthy saves the extra water the plant needs or gardener applies in times of stress. And healthy plants keep on going, so you don’t waste water on establishing a plant that later dies from poor conditions.
Each year various societies present plant awards, but those of us who garden in the West and Southwest await the group of Plant Select top performers. Plant Select, which is a nonprofit joint effort of Colorado State University in Ft. Collins, the Denver Botanic Gardens and professional horticulturalists, lists five top performers at various elevations.
First, a word about why the work of Plant Select and other regional groups is so important. As I said, there are plenty of awards and lots of information in the gardening world. But, for the most part, plants emphasized by magazines and bloggers are great for East Coast and Southeastern region gardeners. It’s different in the high plains and intermountain areas of the country, where altitude, wind, and heat and cold extremes (in a single day and by season) affect plant health. And let’s not forget the water issue.
Plant Select evaluates plant performance in 53 locations throughout five Western states. Here are some of the 2016 Top Performers. See the entire list at Plant Select.
Grand Winner: Blonde Ambition Grama Grass
Blonde Ambition grama (Bouteloua gracilis ‘Blonde Ambition’ PP22,048) was introduced by New Mexico’s David Salman of High Country Gardens (American Meadows). Blue grama is a perfect low-water native grass grazed on by cattle on our Southwest ranches. Salman introduced the blonde ornamental variety in 2011, and this is the second year it has been Plant Select’s grand winner. Beginning in July, chartreuse blooms (seedheads) appear on upright stems, turning to the blonde color as they age. Watching those seedheads wave in winter winds provides xeric gardeners some year-round interest in their landscapes. Although Blonde Ambition can spread by seed, the seedlings are easily pulled up. The grass is hardy in zones 4 through 9 and deer resistant.
Top Performer at 3,000 to 5,500 Feet Elevation
Blonde Ambition also tops the list of lower elevation garden performers in the region. Number 2 on the list is a tree I’ve never grown, but want to learn more about since it also topped the list for gardens at my altitude (6,300 feet). The Hot Wings Tatarian maple (Acer tataricum ‘Gar ann’PP15,023) has bright red samaras, or fruit made of paper tissue, that bloom all summer. It’s also known for its reddish-purple fall color. The Tartarian maple is a relatively small tree, maturing to nearly 18 feet high and wide, and gets by with full sun and moderate to dry water needs. The only drawback for me is that it is not deer resistant, but I could see this gorgeous tree in any suburban garden from 3,000 to 7,000 feet in elevation and in zones 4 through 10. We still might try it, but we’ll have to fence the tree until it reaches a mature height and keep lower limbs pruned.
Top Performer at 5,501 to 7,000 Feet elevation
Although the Hot Wings maple topped the list of performers at this elevation, I would like to give a nod to No. 2 on the list – Turkish veronica (Veronica liwanensis). Veronica is an excellent low-water groundcover. Veronica is evergreen, so it covers portions of our rock garden all year long. In summer, the groundcover blooms. Turkish veronica has cobalt blue flowers above waxy leaves. It only reaches about 2 inches in height, but can spread to 18 inches wide. Although veronica is a xeric plant, its leaves look better with a little extra water in the heat of summer. Turkish veronica is hardy in zones 3 through 10 and deer resistant. The top 5 Plant Select performers at this elevation also include Blonde Ambition, Apache plume and a catmint called Little Trudy (Nepeta ‘Psfike’ PP18,904).
Top Performer in Gardens Higher than 7,000 Feet
Fernbush (Chamaebatiaria millefolium) topped the list for higher elevations. The Western native shrub is xeric once established and grows more upright with less water. It can look more formal with rounded pruning in early winter. Deadheading spent flowers also makes the plant look neater, and should be pleasant considering that the foliage has a honey-like scent. The sweet scent also deters deer. Fernbush can grow to nearly 5 feet high and wide; less water keeps it more compact. The plant thrives in full or partial sun in zones 4B through 8.
These are only a few of the top performers in the Plant Select list. Check out their site for more on current and past top performers, new plant introductions for the region and where to buy plants for High Plains and Intermountain gardens.
Microclimates can be a farmer’s or gardener’s best friend. A few years ago, I wrote about how use of microclimates, or pockets of a garden that have varying temperatures and exposures to weather elements, can expand your choice of xeric plants.
The easiest example of a microclimate is a greenhouse. Windows let sun in and walls, a roof and other strategies help maintain the warmth. Add a heating source (and enough space) and you can grow nearly any plant any time of year.
Subtle microclimates exist all around your yard and gardens. Structures and hardscaping absorb heat during warm hours and release it gradually, helping to protect plants from cold; they also can protect plants from wind. Partial shade shields plants from heat, and slopes or other topography alter how the overall climate affects a given plant.
The Zinnia Experiment
I would like to say that we planted zinnia seeds in three different places simply to later show how microclimates affected their growth and hardiness. But I’d be pushing the truth. I did plant them in several different spots to see how well they grow here and how quickly they bloom, so I can use them as an easy annual filler to add color and even more pollinators to our gardens.
So, we put seeds in open space in our vegetable farm rows, mostly for the pollinators. We also planted some on a fairly exposed raised bed in our xeric garden. Finally, we planted seeds in the lower part of the xeric garden, close to the rock wall. All of the flowers did fairly well, although the ones in the farm area had better soil and more consistent drip watering. They were the tallest and healthiest. The ones in the raised bed took longer to come up, likely because of poorer soil and an inconvenient hand-watering location. The flowers planted in the lower bed did almost as well as the ones in the farm area.
Then the frost came and the healthiest plants burned the worst. They more or less bit it overnight.
The zinnias in the raised bed were nearly as bad, but at least the flowers kept their color (I planned to take photos of them, but hard-working hubby cleaned up the bed before I had a chance.)
The zinnias in the lower bed fared the best. I doubt they will grow or flower more, but they don’t look like they belong in a horror movie.
How to Use Microclimates
The experiment helped me get a sense of microclimates on our land. We’ve always assumed that our farming area is cooler because it is in a sort of mini-valley jut above the river. The dead zinnias demonstrated we were right, especially since those plants were the most robust before the freeze hit. The flowers in the raised bed are more open to cool air; there were no other plants nearby or much hardscape to absorb heat either.
The hardiness of the zinnias in a more protected and “solarized” spot near the rocks was telling. It’s always important to think about sun and shade exposure, but sometimes we fail to consider how placing a few large rocks behind a cold-sensitive plant can help it survive winter. In vegetable gardening, for example, using fabric to cover plants creates a micro-greenhouse effect. And when growing a plant that needs a little less sun or heat, shade cloth or plant placement can lengthen growing seasons.
Microclimates, like the general climate, can vary. For example, a tree that drops its leaves provides no shade until it fills in late spring. As trees mature, they can begin shading a plant that once received full sun; it might be time to transplant a shaded shrub. Windbreaks help slow the flow of cold air streaming up a slope.
Containers offer excellent microclimates, not only because they warm up quickly, but because you can move them to solve sun and wind exposure issues, and all the way inside before the first frost.
You know, I hate to sound ungrateful. We always need rain in New Mexico, if not to water all of the grass, trees and native plants, then to replace our valuable water tables. But in a climate of extremes, especially this summer, we’ve had several weeks of too much water and cool temperatures.
Typically, New Mexico and many Southwestern states receive monsoon rain in the summer, and it accounts for at least half of the rain we receive in New Mexico and Arizona. Monsoons can start around mid-June and end late in September. Ours typically begin around the 4th of July. Monsoons consist of short but strong bursts of rain, usually in the afternoon. They’re fueled by the sun’s warming of Southwest land and nearby oceans at different rates. Water evaporation creates humidity over land, forming the clouds that then depend on temperature, atmospheric pressure, winds and mountain slopes to turn into storms.
Typical is key here, however. This year, we had few to no monsoon storms. Instead, we had unseasonably hot and dry, followed by weeks of unseasonably cool and wet. The first rains did wonders at greening up our native grasses and plants. But then in August, the rain and clouds just kept coming. We just had a break, but now Hurricane Newton has struck Mexico and its remnant moisture is headed for southern Arizona and New Mexico.
If arid areas need rain, why is so much rain bad? Flash flooding is a big problem in desert and mountain areas. But how does heavy rain affect xeric lawns and gardens?
First, plant roots need more than water to survive and thrive; they also need air. When you place a new plant in the ground, for example, you should press the soil around it lightly and avoid compacting it to the point that air can’t reach the roots. When excessive rain falls, the water replaces air in spaces around soil particles. As the water drains through the soil, air can again enter the spaces. But if the water keeps flowing from the surface, or especially pools, the spaces fail to open. Eventually, roots can be damaged and fail to even take up the water that surrounds them.
The second danger of too much water is disease. Any fungal organisms in the soil can more easily attack wet plant roots and cause root rot. Xeric plants are not used to so much water on their leaves and roots. Even leaves are affected by too much water falling and sitting on them, especially without sun and heat to dry them again. Plants are more susceptible to leaf diseases such as leaf spot or blight and have less chlorophyll, which affects appearance and photosynthesis. Eventually, poor leaf health can lead to the breakdown of most of the processes that keep a plant healthy and send energy to fruit and flowers.
Many xeric plants also like sun and a little heat. Native plants have adapted to the Southwest monsoon patterns that usually rule their growing season: A gradual, sunny warm-up in the morning, followed by scattered building clouds. They get a nice drink in the heat of the afternoon, and then the sun comes back out and the air and ground warm up again. This pattern helps dry the plant and soil, and gives the plant plenty of heat and sun. Although nights can be cool in many areas of the high desert and intermountain regions, mornings warm up again after sunrise. Extended periods of cloudy, cool weather lead to too little sun for plants, along with too little heat than they need to thrive and flower.
Even edibles can have problems from too much water. They’re susceptible to root rot, depending on lots of other factors such as soil quality. Leafy vegetables and herbs flower early. Tomato fruit tastes better with moderate water. Too much water, especially inconsistent amounts, can cause fruit to crack.
Keeping Xeric Plants Alive During High Rain Periods
Make sure all plants, and especially those susceptible to root rot, are in soil that drains well. Raised beds, mounds or berms, and suitable containers can help drain soil around plants much better than compacted soil. If you’re not sure how well your soil drains, you can typically tell when it pools or soaks in hours after heavy rains. Or you can try the test in this handout from TreePeople that times water drainage.
Provide air circulation. We all have a tendency to place new plants and seedlings too close together. You might as well get as many cucumbers as possible in the limited space you have, right? But lack of air circulation in crowded plants hides bugs, causes the leaves to maintain moisture, and even can shade ground around roots. Wet conditions harbor new problems that native plants in particular can’t take.
Another problem with extended periods of rain is weed control. Although mostly native, the darn weeds seem to love excess moisture. And before you know it, they crowd and wrap around important garden plants or shading grasses. It’s hard to control them if the ground is too wet to mow or you can’t even get outside.
Build raised beds or transplant susceptible plants to higher ground. We’ve had some drainage problems near our patio and are working on a dry river bed to divert water away from the house foundation and down into a grassy area, where it can soak grass and eventually add to groundwater. One step we took was to divide a blue mist spirea (Caryopteris clandonensis) and move the portion near the patio onto a small burm. The xeric plant is so much happier now.
Whatever you do, don’t water! Turn off drip or sprinkler systems during and after periods of rain; it’s just the responsible thing to do. And don’t assume that yellowing leaves indicate the need to water. With too much water, the leaves look sort of floppy, but too little water usually causes dry, brittle foliage.
Finally, don’t stress. You can’t control weather, so simply keeping your plants as healthy as possible within time and weather constraints is all a gardener can do!
A droopy, wilting plant. It’s a gardener’s instinct to automatically assume: It needs water. And sometimes, that’s a good instinct. But low-water plants just as easily can be killed by kindness as by neglect.
For example, several problems with tomato fruits are caused by too much water, or especially irregular watering. Plants, like people, need some regular hydration. You wouldn’t avoid drinking water for five days and then gulp down a liter, right? One reason drip systems are effective is the consistency (assuming you set a timer) of the amount of water they deliver, along with the slow rate of flow and the fact that they water the soil/roots and not a plant’s leaves. The delivery and slow flow help retain more moisture and nutrients around the roots.
What’s the prognosis?
There are reasons other than drought stress that cause plants to wilt, including problems with the roots. That’s why plants you’ve just transplanted from seed or a nursery container tend to wilt for a few days or weeks. The roots suffer some damage when taken from a pot and replanted. Understand that this is part of the natural course of the plant’s life and help it through without stressing too much (meaning you, not the plant). Even though a plant is waterwise, it still needs extra water until the roots heal and begin to grow, more efficiently pulling water into the plant. If the ground is dry at root level, the roots can’t do their work. Plants that are overwatered sometimes wilt, too, further complicating the “diagnosis.”
Speaking of, most gardeners jump to the worst possible scenario when determining a plant problem. Although disease is a possibility, look not only for symptoms of a particular wilt or fungal disease, but also for possible causes. Do you have evidence of bugs that might have damaged leaves or carried a disease to your plant? Is the plant getting enough air circulation? Is water running off and away from the plant? Has it just been super hot for several days?
The best way to distinguish drought stress from other causes of wilt is by looking at and feeling the soil. Damp soil means the plant has water available; adding water at this point likely won’t help. You should feel an inch or two below the surface. One way is to stick your finger in the dirt to about the first knuckle joint.
Prevent plant stress
When a plant needs water, it’s more susceptible to damage from bugs and diseases. Pests attack the weak. You can prevent plant stress from underwatering by:
Checking the soil as mentioned above; see if there is water for the plant.
Looking for signs of underwatering. These usually include leaves turning yellow and brown, and even falling off. Typically, drought stress begins with lower leaves.
Thinking about the plant’s environment and how it might have changed. Is it windy and hot or muggy and cool in the evenings? Did you last water a plant in the afternoon out of necessity instead of your usual morning routine?
Using a meter or records when in doubt. We have an inexpensive moisture meter for our farm area. If nothing else, it helps confirm or deny my suspicions about the need to water and gives me a basis for comparing soils or drip rates around certain plants. Keeping records of watering, fertilizing and other activities can help manage and diagnose plant problems.
It’s always better to water before a plant wilts, and not to wait until wilting occurs. Although plant roots need to seek water, they also have to find it! When no water is available in the soil around them, plants can begin reacting with wilt, slowed growth or flower and fruit production, and other signs.
Finally, remember there is no hard and fast rule on watering. Much of the advice I see comes from areas that are more humid, cooler, less windy, and at lower altitude than our conditions here in New Mexico. Having said that, you can create conditions that help plants retain moisture, mostly by ensuring healthy soil and mulching. Containers need a little more frequent watering because they dry out faster than the ground. Water container and landscape plants slowly so the moisture drips instead of flooding down. You probably only need to add water to a container when the top few inches of soil are dry.
When it gets hot for a day or two, plants can wilt and require some extra attention. That’s pretty easy to understand. After all, I spend less time outside in the heat of the day because I wilt. I also drink more water. After more than a week of temperatures hovering near or above 100° F, our plants are showing other signs of heat stress that we less often consider.
You would think that living in the Southwest and having mostly xeric plants means plants can tough it out dor a few hot, dry (windy!) days. That’s partially true. But these temperatures are way above normal, at least for an entire day/week and more. Normally, July 1 marks the beginning of monsoons, where clouds build and drop at least some rain in the afternoon, giving the plants and me a break. Not this year. And it’s causing problems for nearly every living thing in our garden. Here are some reasons why:
Heat can reduce bee populations
We noticed about midway through our current heat wave that we seem to have fewer bees in our garden. Of course, I thought I was imagining that. Nope. Bees are especially sensitive to temperature and its regulation. Temperature particularly affects young bees, which are important for keeping colonies going. They tend to keep their hives at 95° or lower, and stress when the temperatures exceed 98°. Bees also need water, and we’ve had two weeks with no measurable rain and consistently high temperatures, even for our evening lows. Here’s a great explanation from Tufts University on how honey bees keep cool (and warm). Despite the fact that we have plenty of flowering plants for bees beginning in spring, the population is lower this summer. I was pleased to see a few survivors on our lavender this weekend, but this is a brand new worry!
Lack of flowering or fruiting
Those bees! They also help pollinate our ornamental plants and especially our vegetables. So, there’s one concern in heat. But I recently was reminded how heat also affects flowering and fruiting. It turns out that pollen loses its effectiveness in high heat. Even though we’ve hit the 100° mark before, I can’t recall it lasting for days and weeks since we’ve been growing tomatoes and other edibles in New Mexico. What’s more, drought lessens the chance that pollen can stick to a female flower.
This is the heat issue we best recognize – leaves wilting on a hot day. Plants “sweat” to cool themselves like we do. With transpiration, water travels up from the roots and to the leaves, where it evaporates through tiny pores under the leaves. So on a hot, dry day, the soil, roots, and entire plant dry out more quickly. Add some wind just for fun, and a plant can wilt or stress. Plants can take more water, but only up to a certain point. Some plants have plenty of moisture and experience what’s called “incipient wilt” during peak heat each day. If they recover by morning, the plant probably is getting plenty of water.
Sunburn and sun scald
Plants can get sunburned. The sun can scorch leaves of plants that typically need a little more shade or lower temperatures. And many plants can burn on super-hot days. The sunburn often leads to brown spots or browning and dying of entire leaves. Sunburn of a few leaves shouldn’t be a problem, but a sign to shade or move a plant if possible. Sunscald is similar damage to bark in high temperatures.
Entirely new or different insects
Aphids, which can be controlled organically, tend to love cool, moist weather. Every type of insect is different, but they’re cold-blooded creatures. Insects can’t internally regulate their temperatures, so they rely on what’s happening in their environment. I’m certain that both weeds and insects change each year depending on weather. Cabbage loopers and leaf miners like heat. Ants? Don’t get me started. And dreaded grasshoppers thrive in drought. When a plant already is stressed by heat or drought, it’s more vulnerable to insect damage or insect-borne diseases.
Some plants adapt better to heat than others. However, young plants still might need more frequent watering in high heat. That’s the part that’s getting to me most. We have some new plants we put in the ground not long before the heat wave hit, and they’re struggling. We’ve even had to water a few xeric and waterwise plants that typically thrive with no water at all. It’s all part of the fun of gardening in the Southwest, I guess. See my previous post for tips on helping plants survive extreme heat.