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.
Gardeners in New Mexico, Arizona, Texas and surrounding Southwestern states face unique challenges. And though climate, zone and even drought conditions can vary from one area of each state to the next, we have some common issues:
Even when our regions are not officially in a state of drought, Southwest gardeners know water is a precious resource that we must protect all year.
Weather extremes are pretty common, especially where mountains meet foothills or plains.
Our states’ populations are highly rural. Although we’ve got plenty of large cities, rural gardeners live long distances from the services and products easy to come by in urban settings. So, sometimes we just have to get creative.
Heat is a major concern when growing throughout most of the Southwest.
But help is on the way, and I’m honored to be a part of a team offering a new source for Southwest gardening, along with Ann McCormick of Ft. Worth, Texas; Noelle Johnson of Phoenix; and Jacqueline Soule of Tucson. We want to make Southwest gardening fun and easier for our friends, neighbors and clients.
Join us as we offer information, ideas and sharing specific to gardening in the Southwest on our new blog, Southwest Gardening.
The new year is almost upon us, but gardeners don’t have to wait until spring to dream, plan and even shop for new plants.
You can take some time in winter to plan your garden. Doing so usually cheers my mood and makes me feel like I’m getting something done, even if I can’t do much outside. Here are a few tips for Southwest gardeners for winter planning and shopping.
Check Out New Plant Introductions
Each year, breeders offer new plants adaptable to conditions or resistant to diseases. Many independent testing organizations and growers conduct trials to see how plants fare in harsh conditions such as heat or drought. A favorite regional source is Plant Select in Colorado. The nonprofit organization tests and creates plants for the Rocky Mountains. You can search or browse their plant selections for zone, soil type, sun exposure, water needs and other characteristics. A new 2017 selection is the Sungari redbead cotoneaster (Cotoneaster racemiflorus var. soongoricus). The shrub is a hardy plant and fall stunner in a xeriscape.
All-America Selections also releases trial information on ornamental plants and vegetables each year. Although some of the plants are not suited for New Mexico gardens, AAS includes regional winners for the Mountain/Southwest region. For example, its 2018 winners include Mexican Sunrise Hungarian Pepper F1. This past summer, I sowed 2017 national winner Dianthus Interspecific Supra Pink F1 seeds in a garden bed and the plant bloomed well into fall. You can find AAS winners at retailers that carry national brands such as Bonnie and Burpee plants or seeds (Johnny’s selected Seeds or Territorial Seed Company).
Regional growers and local nurseries often carry new plant introductions. Typically, you can learn about new plants by subscribing to the company’s newsletter or by following them on social media. High Country Gardens (whose chief horticulturalist, David Salman, is from New Mexico) recently released a list of new plants the company offers in 2018.
Finally, the Sunset Western Garden Collection is designed specifically for Western gardeners. Sunset lists a collection of waterwise plants, but you might have to do some research to find out where to buy the plants you spot there.
Order and Review Seed Catalogs
Growing plants from seed takes a little more work, but can save you money. And some plants do better grown directly in the ground (cucumbers and squash come to mind). Even though you’ll have more success and save water by growing plants suited to your region, it’s fun to shop for rare or unusual annuals for containers or other special spots in your garden. It’s much less expensive to buy seeds for plants that probably won’t make it through the winter.
Most seed companies ship catalogs for free to anyone who requests them and I’ve been receiving mine since before the holidays. In addition, you can find online versions of most seed catalogs. Flipping through catalogs can give you great ideas about new or unusual plants or even inspire where to plant them or ideas for companion plants for a particular flower or shrub.
Read and Research
Catalogs are one source of plant ideas, but local and regional gardening books and blogs should be your go-to sources. Combining information on plants featured in your favorite gardening books with catalogs and new introductions can help you begin planning and shopping.
In your research, look for ideas such as drought-tolerant plants for easy care, plants for birds and pollinators, or colors and textures you long to add to your garden. Think about herbs and vegetables your family loves and see if you can grow a variety within your space or time constraints. And always read books and websites with a critical eye for credible information and plants most likely to grow in your zone, soil type, sun exposure or water availability.
If you don’t have a good gardening book specific to your state or zone, find out if your local master gardeners have published a plant or gardening guide. And check out my Resources page for books and links on gardening in New Mexico, xeric gardening and other topics.
Shop Locally and Online
Some gardeners prefer to touch and see plants in person, at least to decide on colors or shapes they like. Just beware that some chain stores offer plants each year that aren’t suited to your region or at least offer fewer plants tested for Southwest and xeric gardens. For example, no retailers in New Mexico offer Plant Select products, but High Country Gardens sells Plant Select through its catalog and online store. Shopping, or at least researching, online also can save time. Many online catalogs have search filters. You might be able to search by plant name, bloom color, bloom time or average temperatures and rainfall.
Many online nurseries let you order now and then ship your plants at the best possible time in spring for your zone. So, there’s really no reason you can’t get a head start. Happy plant shopping!
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!
As fall temperatures drop, there’s still plenty to do in the Southwest garden. In most areas of New Mexico, freeze hits by mid- to late October. But plenty of sunny days hit in fall here so gardeners can get outside and take care of these chores before winter arrives:
If you still have any vegetables ripening, better harvest them now. Tomatoes and winter squashes can finish ripening inside. If you haven’t harvested and dried herbs, now is the time to trim them back and get them ready for use in the kitchen. Some vegetables, such as kale and carrots, can stay in the ground a while. You can preserve some vegetables with help from extension office publications or other credible sources that address flavor and safety of canned or frozen foods. Finally, I like to pick flowers still blooming and place them in a vase inside, just to make me feel better about the season ending.
There is some debate about what to leave in the garden and what to throw out. You definitely want to throw out any weeds or diseased plant cuttings. Compost healthy cuttings. We even laid some carrots that were too big for our taste out on tree stumps for deer and other critters to eat. It’s personal preference to leave some debris on the ground to naturally compost in place. But if the debris hides unwanted bugs or spores, it’s not a good idea. I usually clean up most plant debris and then use straw or leaves for composting.
3. Preserve Bulbs and Seeds
Check a local gardening book or online to find out how to dig up and overwinter bulbs that can’t handle cold temperatures in your area. In zone 6B in New Mexico, we leave iris, daylily and allium bulbs or corms and should dig up gladiolas and dahlias. Usually, the bulbs just need to be kept cool and dry. You also can preserve seeds from flowers and herbs such as dill or cilantro for cooking or replanting.
4. Leave Some Seeds
Not all flowering plants need fall trimming of spent seed heads. Many can make it through winter and wait for summer trims. And birds love dried up seeds on sunflowers, cosmos and other flowering annuals. Plus, by leaving the seeds on, you increase the chance that some native grasses or flowers will reseed.
5. Evaluate Plant Placement
As you clean up and assess how plants look at the end of their growing season, you can evaluate plant placement. For example, some of our green beans did not fare as well as last year. I believe the spot I planted them in this year got more late summer shade from a neighbor’s tree than I anticipated based on early summer sun. Some plants might have grown too large for their spot or get too much water from runoff. Take some notes and consult local sources so you still have time to decide whether you can move them this fall. Or plan where they’ll go in spring, especially before buying new plants!
In New Mexico, we mulch for two reasons: to conserve water and cool roots in summer and to warm roots during cold winter. I typically mulch as part of fall cleanup and near the time of the first freeze. Most plants that are native and appropriate for your garden can get by without mulch, but it helps protect tender plants from hard freezes in winter. Mulching needs to be a few inches thick to insulate and to cut down on weeds.
7. Protect Plants
Some of my gladiola bulbs came back and rebloomed without being dug up. But I mulched them pretty heavily with leaves. In addition to mulching, you can put buckets around plants to help keep them warm, especially in winter wind, or to keep deer from destroying them (adding a “lid” made of chicken wire or similar material that lets in sun and moisture but not curious critters). Plants in containers that are tender or annual in your area need to come inside, We move outside containers against a south-facing wall for warmth and to protect against wind.
8. Empty Containers
It’s time to empty all those containers with edibles and annuals that are dying back. You’ll need fresh potting soil next year and it’s better to store containers empty. We empty soil from our containers (unless the plant had a disease) into garden beds and large stock tank containers that need soil. You can also save potting mix in plastic sealed containers, but it should be mixed with fresh potting soil and compost when replanted in the spring.
9. Amend Soil
If you have new garden beds or some that need better soil, fall is a good time to improve soil health. Adding some compost gives it a chance to break down, as does covering beds with leaves that fall from trees. And it makes the spring preparation easier. There are many ways to amend bad soil, such as planting cover crops before frost or having a soil test so you know how to better balance pH in your growing beds. But gardeners learn to tell when soil is compacted. It’s hard to go wrong adding a little organic matter in fall.
10. Enjoy Time Outside!
Fall is a favorite season for a reason. Cool nights and warm days make it hard to stay inside, even when there are few chores to do. And enjoying even the final flower blooms before frost arrives is part of the reason you work hard to make your lawn and garden look nice.
Soak it all in and dream about spring, when you will feel renewed energy and enthusiasm for garden chores.
People who love gardening know that winter and early spring can drag on and on. So it’s good to have a project in your back pocket to get outside and improve the garden during the off-season. I’ll share our experience and give a few tips on creating or replacing your own garden path.
The weedy gravel walkways in our rock garden needed help. We replaced the old with new landscape fabric and crusher fine, also called decomposed granite. There were several reasons for the project, mostly the weeds I mentioned.
We estimate that the original paths, installed by the previous owners of our property, were about 10 years old. The weeds and grasses began to poke through the thin landscape fabric and I spent nearly all of my free time bent over pulling weeds out of rocks.
We needed to get the new path in before spring planting. And we were done ahead of schedule after:
Spending 2 to 3 months cleaning out old rock and installing new crusher fine.
Moving and replacing more than 500 border rocks.
Laying about 10.5 rolls of 50-foot landscape fabric.
Adding nearly 200 new pavers.
Hauling and shoveling more wheelbarrow loads of old gravel and new crusher fine than we could count.
Reasons for crusher fine
Crusher fines are just that – small particles of crushed rock. So although it might seem crazy to replace rock with rock, hear me out. The landscape gravel was made up of rocks about three-fourths inch in diameter. These let sun, air, water, and especially weed seeds filter down through the layers and held just enough blowing dirt in to feed the seeds. A thin fabric can only do so much to stop weeds from taking root, especially once any tear in the fabric occurs.
Crusher fines are made of tinier particles and dust, so after you level and tamp them down, the surface evens out and compacts, forming a hard layer that feels more like concrete than rock, but maintaining a rocky, natural appearance. To help prevent weeds, the layer has to be thick – we tried to keep it at two to three inches all the way around. Crusher fine also comes in landscape colors, although we had to pay plenty to have ours trucked in from 45 miles away.
Using landscape fabric
The thin landscape fabrics available in big-box stores don’t cut it in most situations for weed control. We ordered ours online from Greenhouse Megastore. It’s Weed Barrier brand with a 20-year warranty.
The fabric is touted as great for xeriscaping and allows air, water, and nutrients through, but blocks light. Since we used it in a path, we didn’t care about light (and less is best for weed seeds) but we didn’t want standing water. Both the fabric and crusher fine are water permeable, so the water seeps down, eventually back into the ground.
The fabric was heavy duty but easy to work with for the most part. Our garden is a circle, with smaller circles and curves throughout. My theory is that any crack/slit/opening in the fabric is an invitation to a hardy weed like field bindweed. But to make curves, you have to carefully slit and overlap the fabric. The fewer cuts the better.
So, out with the old and in with the new. The worst part of the project was scraping, shoveling and hauling off the old gravel. And what do you do with several tons of rocks? Our first step was to repurpose the old gravel in a few beds (over landscape fabric and with cuts for plants) and to add depth to another path in the front yard that has the same gravel. No way we could tackle it too, and I hope that by adding to the depth, we made it a little more difficult for weeds to root. Someday, we’ll have to move that gravel again and replace it with crusher fine. But not today. Or this month or this year…
We also hauled loads of the old gravel to our vegetable garden and dumped it on strips of fabric left over to cut down on mud and weeds in the walkways. As for the rest, it’s in a pile, waiting for friends to claim it or for Craig’s List.
Here are a few tips on creating a garden path with crusher fines:
If you can design your own path, consider gentle curves when possible. Circles are tough. Mention this to a landscape architect if you have one, so you can be ready to replace the path when the time comes or get an estimate of the cost for a landscape company to do so.
Invest in professional quality landscape fabric.
Work in sections, leaving fabric in the longest continual length possible, which might mean leaving the roll at the end of a section. (We just turned the wheelbarrow upside down over the roll to protect it from deer damage.)
Overlap the fabric by several inches at cuts and intersections, and try to avoid large folds.
Get some fabric under borders such as pavers, even if it means lifting and replacing the hardscape.
Place border rocks or pavers on fabric before adding crusher fine.
Work in sections to spread crusher fine in a thick, even layer. We used the back (straight edge) of a bow rake.
Invest in a tamper (ours was about $40).
Spray the crusher fine with water before your last tamp. It helps bind the crusher fine mix. (And the color of the path really comes out after rain.)
Keep a small pile of crusher fine handy for a few weeks, or at least after a few rains. You might find low spots or phantom folds poking through. Just add a few shovels to the spot and level it with the existing crusher fine.
And then enjoy! It’s like a dream to walk on and has a really neat appearance.
Winter has come late this year, and that’s alright with me. But we’re sure to face a hard freeze soon and it’s time to protect some plants.
The first line of defense, of course, is to choose plants that are hardy down to your average low winter temperature. These plants might look dead in winter, but they come back as spring warms the air and ground. We can’t control the weather, however, so when exceptions to your typical low hit or you really want a plant on the border for your temperatures, you can help that prized plant make it through the winter. Here are a few tips:
Planning ahead helps. When placing a new plant in your landscape, be sure to consider its winter hardiness when you plant. Placing it in a warm microclimate, such as against a south-facing wall or fence, can keep the plant a few degrees warmer when temperatures dive on winter nights.
Mulching over bulbs or around the roots of perennials and even trees can help the ground retain heat. I use raked-up leaves and sometimes straw. In addition, I use rock mulch around xeric plants. The rocks absorb and reflect heat.
Sadly, we can’t all afford or find space for an actual greenhouse. You can buy or create mini-greenhouses around a few plants. Ours only need a small boost, so we often use 5-gallon buckets with the bottom cut out. We sometimes top them with wire for deer protection or cloth for extra warmth. Glass adds even more warmth and a cloche, French for “bell,” is a glass jar that can cover individual plants. There are lots of ideas online for constructing mini-greenhouses out of plastic and wood or PVC pipe, but you’ll need to remove anything that airtight as soon as the temperature warms back up following a freeze. Otherwise, condensation forms inside; the water drops refreeze and actually can damage your tender plant.
A sheet or blanket wrapped around an entire plant helps protect it from freeze on the occasional cold night. Again, this is a temporary fix. If you have an entire section of plants that need protection, it’s better to rig a system with hoops or sticks and fabric row cover. If leaving the cloth on the entire winter, be sure to use a landscape fabric that allows sun and water through. I like to open these on warm, sunny days.
Plants need to head into winter in a healthy state. That includes keeping them watered (at a reduced rate) if you haven’t received precipitation recently. Cold, windy air dries plants out and stresses them. There is no need to prune most perennials before winter. It’s best to let them die off naturally, feeding birds with seeds. You’ll trim trees while they’re dormant in winter. When freeze threatens, you can water the mulch around the plant, but avoid hitting the leaves and branches. The water in the mulch helps hold heat in. I’ve also seen suggestions of placing used plastic bottles filled with warm water around the mulch to conduct some heat during a freeze.
Bring plants inside
No greenhouse? How about the house? My largest geranium loves the sun from our bathroom window, and the humidity likely helps as well. We have so many plants to bring inside that some have to live in the garage, where it can get chilly but hasn’t gotten below freezing. If you want to invest some money, you can buy grow lights for plants that need more sun than available in your home or garage space. Spray the plants off and let them dry a bit before carrying them inside. This helps reduce the chance that bugs tag along for the ride.
Check out lots more ideas on our Pinterest boards (What’s wrong with my plant? and Greenhouses)
Hardscaping is use of anything other than plants, really, in the garden. So it includes rocks, fences, walls, walls made of rocks, pavers, stepping stones, lighting, gravel (made from rocks) and found or repurposed objects. Did I mention rocks?
Here’s the problem: When people think of xeriscaping or converting high-water lawns and landscapes to more waterwise plans, they often turn to landscape gravel, rock borders and concrete to fill their landscape. Done! But the best xeric landscapes mix functional and attractive hardscaping with plants for full effect.
Pros of Hardscaping
I find that after touring a public or private garden, my photos often include fences, garden art and other hardscaping features. I guess I’m drawn to them. Any plant can shine when placed before a solid wall or large boulder, but those with tiny flowers and foliage really pop with a backdrop. And you don’t have to use large, expensive artwork or structures. Sometimes, all you need is a well-placed rock or container.
Aside from aesthetics, hardscaping features provide function in the landscape. Pathways lead the gardener, visitor and the eye in the best direction, or help a homeowner get from one point to another more easily. Fences and walls improve privacy and arbors and pergolas add to shade in sunny garden spots.
Finally, homeowners often put in hardscaping to minimize watering and plant care. Most nonplant items in the garden require little to no care and last for years.
Cons of Hardscaping
Replacing lawn and plant materials with hardscaping can lower maintenance, but can create too much heat in the lawn and garden. A concrete patio or gravel-covered yard is way hotter than turf and plants. That being said, a mix of both helps lower water use and costs. If done right, homeowners can enjoy their gardens and save water.
Only plant materials provide important food and pollen for animals and insects; bushes and trees also provide better shelter than the eaves of your home. Adding birdhouses and beehouses near plants can help nature’s garden visitors. Too much concrete and gravel also makes a garden seem unfriendly to people. You probably want privacy and a place to sit or walk, but don’t you also want flowering or edible plants nearby? If a big patio is necessary for entertaining, add container plants on the ground, walls or even the furniture.
Finally, be sure to consider existing trees and other plants you plan to keep when converting lawns to gravel. Trees need deep watering, and the roots stretch out at least to the tree’s canopy, which is how far out branches and leaves extend. So providing a pretty little circle of mulch around the trunk likely isn’t enough.
Some of my favorite xeric landscapes combine a few featured plants such as a shade tree or colorful bush with low-growing annuals or groundcovers that cascade over steps or rocks. Combining hardscape and plant features is a smart xeriscaping strategy and a way to enjoy your lawn for years to come.
Gardening can be hard work, and there’s no shame in taking a break now and then. Besides, why pour plenty of time and love into your garden if you aren’t spending time in it, whether reading, visiting with friends and family or simply enjoying the view.
Yesterday, I visited some gorgeous private gardens in the Atlanta area where the owners get it; I kept spotting cozy and elegant sitting areas. We’re adding a few spots with chairs and benches around our property, so maybe I was more alert to these features of the gardens I toured. Or maybe the areas for relaxation were just too good to pass up.
And although Atlanta’s landscape differs markedly from ours in the Southwest, we all can take a few ideas from these pleasant garden rest stops. Enjoy the pictorial tour!
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!