Every drop of rain that falls on your landscape ends up somewhere. Where that water falls and where it ends up is called a watershed.
Rainwater may be absorbed by plants, sipped by local wildlife, or it may evaporate back into the atmosphere. Rainwater can also wash away valuable topsoil, carrying fertilizers and pollutants into our groundwater supplies, rivers, lakes, and oceans. In fact, the California Native Plant Society tells us that urban drool is the #1 source of ocean pollution. To prevent water waste, pollution, and runoff, a new approach to landscape design was created to protect our precious watersheds.
Watershed approach to landscape design
The watershed approach to landscaping uses garden design, installation, and maintenance methods that take advantage of natural processes to create spaces that are water efficient, while providing abundant plant growth, good habitat, and an enjoyable place to be. The watershed approach captures, cleans, and collects rainwater to slow, spread, and redirect its flow in ways that reduce the need for other irrigation. The benefits of using a watershed approach include:
How much rainfall do you get?
Every yard is different, but your average 2700 sq. ft. roof in the Bay Area can collect more than 25,000 gallons of water each year! You can use the USGS rainfall calculator to determine how much rain water falls on your roof in any given storm, simply by entering your home’s footprint dimensions (length x width) and the amount of rainfall measured by you* or reported by your local news station. During a storm that drops one inch of rain onto a half-acre lot turns out to be nearly 14,000 gallons of water! Rain barrels, ponds, swales, and filtration tanks are all different ways you can collect rainwater.
Where does that water go?
All too often, rain water falls on buildings, roads, and concrete, where it collects pollutants and debris, and carries them to our groundwater. Our garden plants never have the opportunity to soak it up. On the other end of the spectrum, rain water either floods an area, carrying away valuable topsoil, or it gets stuck in one place, where soil, plants, and organisms begin to rot. Using the watershed approach removes those problems by studying where water comes from, where it goes, and taking actions that redirect water flow to be more efficient and environmentally sound.
First flush and absorption areas
First flush refers to the first 3/4 to 1 inch of rain that falls after a dry period. This rain water contains higher levels of pollutants and debris than the rain that follows. Can you filter those pollutants out or redirect this water to less vulnerable areas? After that water is dealt with, how much permeable soil is needed to absorb your expected rainfall? First, you will need to know how deeply your soil absorbs water. You can determine this by going outside after a few days of rain and digging in with your shovel. How far down did the rain actually go? This number can help you determine how big of an absorption area you will need for the expected rain.
Example: You live in a 1,000 square foot house in San Jose, CA, where you receive an average of 15 inches of rain each year. Using the USGS rainfall calculator, you would discover that your house can collect 9,351 gallons of water in a year. To absorb all that water, you would need to divide the volume of water by 7.48 for a per foot absorption area. (There are 7.48 gallons of water in a one cubic foot of space.) This gives you 1250 square feet needed to absorb all that water, assuming that your soil absorbed water down to a depth of one foot. If it only went down 6 inches, the 1250 sq. ft. figure would have to be doubled. If you don’t have that much space, how can you prevent runoff? What if that’s not enough water?
What are other sources of irrigation water?
Be sure to check with your local municipality for laws regarding water collection (there have been countless wars started over water rights). You can collect water from your bath or shower, as it heats up, in a bucket. You may be able to redirect the outflow from your washing machine to irrigate ornamentals. Even the water left over from cooking pasta and vegetables makes useful water for the garden.
How much water do you really need?
There is no excuse for wastefulness when it comes to water. You might be surprised at how little water you and your garden actually need. Our household has reduced water consumption to only one-fourth of what it was three years ago and we get more production from the garden! This is possible by:
Other factors to consider when using the watershed approach:
Start using the watershed approach in your yard by asking yourself these questions:
What’s really nice about the watershed approach is that it takes advantage of natural processes that have evolved over thousands of years to work without any help on our part. Native plants and those suited to your microclimate require less care, which translates into less work, less expense, and a healthier environment.
Activity: Inventory your landscape’s water needs
Every drop of water that you are able to use more efficiently protects the environment and your bank account.
A hose is a hose is a hose. Right? Well, no.
Garden hoses and soaker hoses sure make watering plants one heck of a lot easier than back in the days of carrying buckets, back and forth and back again. At 8 pounds a gallon, that water gets pretty heavy. Our handy green garden hose makes light work of a regular garden task, but what’s in that hose and can it leach out into our soil, where it can be absorbed by our plants? The answer is uncertain.
Food grade hoses vs. garden hoses
After living in an RV for 5 years, I understood all too well the importance of my white hose with its blue stripe. This particular hose was used to bring potable water into my home. (Potable means safe to drink.) What made that hose different from your standard green garden hose? Being sold as a food grade hose means it is covered by the Safe Drinking Water Act. This bit of regulatory protection limits the materials that can break free from the hose and enter the water moving through it. Garden hoses are not (but I think they should be). Because garden hoses are not covered, they can contain significantly higher levels of lead and other toxic chemicals.
Garden hose test results
Public opinion and concern have pressured regulators to look into the issue of toxic garden hoses, but it’s slow process. Many garden hoses contain significant levels of lead, BPA, and phthalates. The bass fittings on the ends of garden hoses have been found to contain dangerous levels of lead about 1/3 of the time. BPAs are used to make hard, clear plastic. The Food and Drug Administration says BPAs are safe, but has banned their use in infant bottles and sippy cups. Huh.
Garden hose materials
The Environmental Protection Agency (EPA) actively encourages manufacturers to use “old tires and recycled plastics” to make garden hoses. This is great for reducing the amount of trash in landfills but it begs the question of what, exactly, is in those materials and how tightly are they bound to the hose?
According to the Centers for Disease Control and Prevention (CDC), garden hoses contain chemicals called phthalates. Phthalates, or plasticizers, are used to make plastic strong and flexible and they are found in all standard garden hoses. Drinking water from a hose made with phthalates puts these chemicals in your body. Watering plants with the same hose puts those chemicals in your soil. The National Institutes of Health (NIH) classify phthalates as "reasonably anticipated to be a human carcinogen.” Another huh.
If all that weren’t enough, the National Center for Biotechnology Information (NCBI) warns that garden hoses provide the perfect growth medium for Legionnaires’s disease! Spraying water into the air turns the Legionella bacteria into an inhalable aerosol.
Food grade garden hoses
In the greater scheme of things, the amount of lead and other chemicals that end up in your soil, plants, and food from a garden hose are probably negligible. There is debate about whether BPA molecules, which tend to be large, can even be absorbed by plants. I certainly don’t know. What I do know is that I want to keep carcinogens, lead, and other toxins as far away from me and my garden as possible. These tips can reduce health risks:
If you are concerned about the possibility of chemicals leaching out of your garden hose, you can always do what I did and switch to higher quality products. Companies, such as Water Right, eartheasy, and others, offer garden hoses made to food grade standards. In my opinion, it’s worth it.
Hose trivia: The Irrigation Museum tells us that the first residential hose nozzle was patented in 1877. Who knew there was an Irrigation Museum???
Whether you are talking about rain, plant food, or political arguments, there comes a point where nothing else can be taken in. Saturation is one if those points of perfect, momentary balance between plenty and too much.
To the untrained eye, a garden looks tranquil. The quiet greenery is peaceful and calm. It’s like watching what appears to be a Perfect Family, with everything running smoothly - no conflicts, no stresses, no worries. Of course, in reality, it’s nothing like that. The chemistry and conflicts that occur in gardens and relationships are never as smooth as it looks from the outside.
Saturation tends to sneak up on me. The amount of water I use to irrigate the garden in one month doesn’t work as well in another. The daily 25 minutes of weeding in one week is enough to keep down the competition, but in other weeks, the weeds practically race across the yard. Recognizing the delicate balance between enough, plenty, and too much is part of what separates a successful garden from one that is struggling.
Water is an obvious case of saturation. Whatever your soil structure and composition, there are only so many macropores and micropores that can hold onto water. Sand will have a lot more porosity and better drainage than the Bay Area’s heavy clay. But even clay reaches a saturation point. That’s when gravity pulls the water down and away, preventing your plants from drowning, but also leaching away valuable nutrients. If it can't go anywhere, it pools around your plants, drowning them and creating mosquito breeding grounds. Just enough water for each plant can be difficult to determine. In dealing with California’s drought, our family has reduced the amount of water we use to only 25% of what we were using 3 years ago and guess what? All the plants are fine. In fact, they are better off than they were before. Oops.
Fertilizer is another case of enough is great and too much can be deadly. Many fertilizers can burn plants once the point of saturation is reached. If you are up for a fun read, try Don Mitchell’s 'Moving Upcountry' series. He has a hysterical account of using too much nitrogen and destroying his tractor. Of course, there’s nothing funny about burning your garden crops with too much fertilizer, but it happens.
More common, and frequently unseen, is the case of certain minerals saturating a soil and creating an imbalance. After sending soil samples to a lab for testing, I learned that my heavy clay soil has tons of every nutrient, except iron. Unfortunately for my plants, they need iron to be able to absorb everything else. Getting your soil tested by a local, professional lab is the only way to really know what’s in it. It’s a complex dance of chemistry and molecules going on every moment in the garden. A nutrient imbalance or troublesome saturation can change everything.
Saturation can also refer to sunlight, garden design, and your pantry. Are your plants showing signs of sunburn? Are you saturated with tomatoes by autumn? Do you still have butternut squash left over from two years ago? Are you tired of looking at a monotonous sea of green?
Avoiding saturation may mean nothing more than adding some color or a piece of art to the landscape. It may mean planting shade-loving plants under sun-loving plants. Or it may simply mean planting what you and your family (friends and neighbors) will be happy to eat.
Have you ever over-planted something to the point where you never wanted to see it again? How has saturation impacted your garden?
One of my favorite sayings reminds us that, “Too much of a good thing is a bad thing.” This is especially true when it comes to rain.
As most of us learned back in school, rain occurs when water evaporates from the Earth’s surface, condenses into clouds, and then falls back to Earth. In doing so, this water cycle moves minerals, chemicals, dust, seeds, plants, and even insects around.
Now, after years of drought, the Bay Area is happy to receive rain, any rain, all the rain it can get. Thirsty lawns, marginally watered ornamentals, and gardens of every size, shape, and style absorb the rain as fast as they can, except for when they can’t - and that can be a problem.
As rain falls on your garden and landscape, one of the first things that happens is the dust is washed off the leaves. This is good for the plants because it allows them to perform photosynthesis more efficiently and it makes the neighborhood less desirable to spider mites. That dust-filled water falls to the ground where it is probably absorbed right away. In some cases, the ground is so dry that it becomes hydrophobic. Hydrophobic soil actually repels water, causing run-off and erosion.
Assuming your soil can absorb the rain water, gravity and surface tension will pull the water deeper into the soil, hydrating roots at various soil levels, until it reaches bedrock or an underground waterway. If the water cannot keep moving away, it will pool, creating mud bogs that can drown your plants. If it can move away, it will leach nutrients and chemicals with it, which is why it is so important to avoid using excessive fertilizers and pesticides.
When really heavy rain hits many parts of California, we also have to watch out for flash floods. Creek beds that have been dry for so long that no one remembers when they were ever wet suddenly play host to a crashing, raging wall of water, seemingly out of nowhere. That’s not very likely, here in San Jose, but it can happen in flatlands surrounding the hills. More often, rain causes car accidents because so many people forget about the oil on the road (and their good manners), but I digress.
I collect rain water from the roof of my house with three rain barrels. Of course, these 65-gallon rain barrels fill up surprisingly fast, so I have to connect a hose to the spigot at the base and redirect the excess somewhere else, usually to the lawn or, if it’s been raining a lot, to a swale near my fence. I recently learned about rain gardens and I may install one someone in the landscape. You’ve already seen rain gardens, you probably just didn’t know it. Rain gardens are sunken areas with native perennials, shrubs and flowers planted around the depression. Most of the time, rain gardens are dry. When it rains heavily, the sunken area fills up with rain. Because there are so many plants in a rain garden, the water is usually gone within 12 to 48 hours, eliminating concerns about mosquitoes. According to The Groundwater Foundation, rain gardens allow 30% more water to soak into the ground, removing 90% of the nutrients and 80% of the sediments from the water, compared to a traditional lawn. [Looks like I’m going to have to do a bit more research on rain gardens!]
So, if you are dealing with rain, keep a look out for soggy areas that need better drainage and enjoy the time you would have spent watering by doing something relaxing indoors instead!
How do you handle too much rain in your garden?
Brown rot is a fungal disease of stone fruits, such as nectarine, peach, apricot, cherry, plum, prune and almond trees. It is caused by the Monilinia fructicola fungus.
Brown rot identification
Brown rot appears as brown, withed blossoms (blossom blight), cankers, and rotten fruit. Infected twigs may also display brown, sunken areas that ooze a sticky brown goo that contains millions of fungal spores. Fruit mummies can contain even more potential infestations.
Brown rot control
Removal of mummies and pruning out diseased tissue is the best solution, once an infestation has occurred. Copper fungicides can be used to minimize fungal populations.
How to prevent brown rot
Pruning for better airflow can reduce the likelihood of infection, as can furrow irrigation. Do not allow sprinklers to wet blossoms.
If we say something is sustainable, we mean that it can keep going. Since agriculture and gardening are critical to our food supply, being sustainable is pretty darned important.
Until the 1980’s, food production was focused on the industrial production of single species (mono crops), using chemical fertilizers and pesticides, until the soil was exhausted. You can only do that for so long, before you run out of places to grow food.
In 2002, at the International Society of Horticultural Science’s First International Symposium on Sustainability, it was agreed that sustainable agriculture and gardening were critical for the “well being of human societies”.
Sustainable gardening incorporates practices that reduce water, energy, time and chemical consumption, while producing food year-round and protecting the environment. These practices take the following issues into account:
Design for sustainability
Whether you already have a garden or are just starting out, you can design a garden or landscape for sustainability. Native plants are always your best bet because they put millions of years of evolution to work for you, conserving water, reducing the need for chemicals, and freeing up your time. Lawns are notorious water wasters and, quite honestly, most of us are not British aristocracy. Other plants, such as oregano, yarrow, or clover, make excellent, low-growing ground covers that use less water and rarely, if ever, need mowing.
These tips can help you create your own sustainable garden:
Mites are tiny spiders that suck the living juices from nearly a thousand different garden plants. Being closely related to ticks, some varieties of mites also suck blood from mammals, like us! The study of mites and ticks is called acarology.
Mites prefer soil that is high in organic content with plenty of moisture. Unfortunately, that describes nearly all of our container plants and many of the microclimates found in Bay Area gardens. A highly adaptable critter, there are over 42,000 species of mites worldwide. Aside from nest mites, dust mites, varroa mites, and many others that attack birds, animals, and bees, respectively, common garden mites include gall mites, spider mites, and thread-footed mites.
How could something so small be a threat to plant health? Well, normal leaf behavior includes water regulation. This is done by opening and closing small valves (stoma) on the underside of leaves. If there is too much water, the plant will drown. Not enough water, and critical life functions cannot occur. It’s an elegant balancing act until spider mites enter the scene. Using piercing mouthparts to puncture the leaf surface to feed, a mite-infested leaf will have thousands of tiny holes poked in it, allowing too much water to escape. A plant can go from healthy to near death in just a few days. Mites can significantly reduce citrus, berry, almond, and annual vegetable crops. They are a serious threat in our hot, dry climate.
Galls are areas of abnormal plant growth, similar to warts or benign tumors on animals and people. Gall mites get their name because, as they feed, deformations appear. Fuchsias are especially susceptible to gall mites in San Jose, California.
Spider mites get their name because they build protective webs around eggs and feeding areas. The most common spider mites in the Bay Area are the two-spotted spider mite, the strawberry spider mite and the Pacific spider mite. They are often found on the underside of leaves, where they pierce plant cells to feed. These mites are very small, usually less than 1 mm (0.04”) long, so they are all too easy to overlook until the damage becomes significant. It doesn’t take long for a population to develop, either. A single female can lay 20 eggs a day and live for up to 4 weeks. Since each offspring hatches within 3 days and becomes sexually active in only 5 days, a single, fertilized female and her offspring can produce millions of spider mites in a single season!
An interesting note: female spider mites have two sets of chromosomes, like we do, but males only have one. If an egg is fertilized, it will hatch female. If it is not fertilized, it will hatch as a male. Also, female spider mites are able to “decide” whether to lay male or female eggs, depending upon environmental conditions. To control spider mites, insecticidal soap is your best bet. Neem oil can also help. If chemical pesticides are used, repeated applications will be necessary (and progressively ineffective, as mites can develop resistance).
Most thread-footed mites, also known as white mites, feed on fungi and algae, a few varieties have evolved to attack leaves. Specifically, the cyclamen mite and the broad mite are able to inject toxins that thin the cell walls of mature leaves. Damaged leaves display puckering, twisting and stunting.
The only known effective chemical pesticides against mite infestations are endosulfan, dicol, and ethyl bromide fumigation. Endosulfan was globally banned due to its toxicity to humans and its ability to accumulate in an environment, Dicol is considered a “moderately hazardous” pesticide, closely related to DDT, and the state of California classified ethyl bromide as carcinogenic and a reproductive toxin - not anything you want to be spraying on food plants.
Broad spectrum pesticides do more harm than good because they also kill beneficial insects that feed on mites. You can buy predatory mites that help control mite infestations. If an infestation is discovered, sprays of water can be used to displace mites and make life harder for them. Garlic extract and oil of clove, rosemary, cinnamon, mint and others can also be effective. These natural treatments can be dangerous to plants, however, so use them carefully. The same goes for sulfur, especially on cucurbits. Observation and prevention are far easier than eradication.
One of the easiest ways to avoid mite infestations is to create a quarantine area for new plants. This protects established plants from new infestations and gives you the time needed to see if a new plant is carrying any pests or diseases. Also, proper irrigation reduces water stress in established plants, making them better able to protect themselves. Mites prefer dusty conditions, so keeping garden paths, trees, shrubs and other areas clean can significantly discourage mites. Encouraging beneficial insects, such as lady beetles, lacewing, and pirate bugs, by providing water and habitat, can significantly reduce mite populations without the use of pesticides or sprays.
Benefits of rain barrels
If you live in the Bay Area, you have probably noticed that our water is getting "harder". This is because of the minerals that are being dredged up from the bottom of reservoirs and ground water sources. It's not necessarily a bad thing (unless you are a coffeemaker or an iron), but it doesn't taste as good as it used to. Unlike the water that comes out of our faucets, rain water collected in rain barrels is free of chlorine and other chemicals used to make it potable. Watering container plants and in-ground plants with water from rain barrels means less potable water is being used. If you wash your hair from rain water, you may find that your hair feels softer.
Your average 2700 sq. ft. roof in the Bay Area can collect more than 25,000 gallons of water each year. Most rain barrels are significantly smaller than that, so you will only be able to collect so much before that water has to go someplace else, but it still ends up saving on your water bill.
The down side of rain barrels
As good as rain barrels are at conserving water, there are certain things you should know before you go shopping for your very own Amazing Rain Catcher. Here is what I have learned:
Now, I’m not trying to discourage you. As I said, I have three rain barrels and I use them year round. In the peak of summer, if I have managed my 65-gallon rain barrels properly, they give me a total of 195 gallons of rain water to use on my plants that would have had to come from the taps.
Let me know if you have any questions about rain barrels in the comments section.
Crown Rot may sound like a great punk rock band, but it can destroy many plants in the garden.
Crown rot is caused by a soil fungus that is nearly guaranteed to kill a plant once infestation occurs. It favors heavy clay soils and wet conditions that occur with over-watering and flooding.
Crown rot symptoms
Signs of crown rot include rotted plant tissue at ground level, wilting, leaf drop, trunk discoloration and leaves that turn yellow or even red or purple. Established trees may ooze a dark sap around the infected area. Older plants may survive a few years, but young plants normally die quickly.
If crown rot is found in the garden, your best choice is to pull up the plant and discard it. In rare cases, a tree can be saved by pulling soil away from the trunk and cutting away diseased areas. Fungicides are ineffective in treating crown rot.
Preventing crown rot
Prevention is the best course of action in areas prone to crown rot. To reduce the likelihood of crown rot taking hold, use these preventative measures:
No, I’m not talking about Medieval medical practices!
Clay soil holds far more water than sandy soils, but every soil has a holding capacity. Once that limit is reached, gravity will pull the water downward into underground waterways where it will ultimately flow to lakes and oceans. As it flows away, the water carries nitrogen, salts, fertilizer, pesticides, fungicides and whatever else was in your soil with it - leading to a potentially dangerous chemical soup that can wreak environmental havoc. Leaching also moves valuable nutrients out of reach from your plants roots.
To avoid leaching, it is always a good idea to water only as much as is needed. You can see for yourself where your irrigation water is going simply by inserting a moisture meter next to the plants you intended to water (but not too close). Many people are surprised to discover that the water intended for their tomato plants actually went in another direction due to hardpan, sandy pockets, or poor soil structure. Improving soil structure with compost can improve drainage and help prevent leaching.
If it has holes in it, water will find a way through it.
This is true for your tent, your roof, and your garden. In fact, permeability is pretty much the name of the game when it comes to plants and soil.
The rate at which water flows through something else is called permeability. If you’ve ever tried buying a home, you were probably required to pay someone to conduct a perc test. Real estate percolation tests are done to make sure that your house won’t wash away when it rains and that your septic system won’t back up into the living room. A percolation test In the garden can help plants get the water and nutrients they need without drowning. Before we learn how to conduct a perf test, let’s find out why it’s important.
Water in the soil
In the garden, water and air flow in and out of soil, leaves, and even individual plant cells. For a plant, this is the Stuff of Life. The water and air that flow in and out of a plant’s cell walls carry sugars, minerals, oxygen, carbon dioxide, hormones, waste products, and chemicals that allow your plants to thrive or die. [If you’ve ever battled poison ivy or poison oak on your property, you can use a leaf spray that gets absorbed through the stoma (sort of like pores) and carried down to the roots through the phloem. The chemical kills the plant at the roots. This only happens because of the permeability of the leaves.]
Now, too much of a good thing is a bad thing. Without adequate permeability, your plants will drown, suffocate, dehydrate, or starve. Not good. Healthy soil is made up of different size bits of sand, loam and clay. The spaces between these bits are called macropores and micropores, depending on their size. Air and nutrient-rich water pass through these spaces, feeding and nurturing your plants. If the spaces are too small (or absent), plant roots cannot get to the food and air they need to live.
So, how can you, as a gardener, improve the permeability of your soil?
• avoid overwatering
• aerate compacted soil
• apply mulch and compost
• avoid walking on wet soil
Signs of permeability problems:
• standing water
• hydrophobic soil
• chlorosis (loss of green color)
How to conduct a percolation test for soil permeability:
Ideally, you will want the water to drain at a rate of one or two inches per hour. Of course, sandy soil will drain much faster, taking valuable nutrients with it. You can improve the holding capacity of sandy soils by adding aged manure or compost. If your soil contains more clay, like mine does, you can improve permeability by adding… you guessed it - aged manure or compost! Compost and aged manure add organic material to the soil, creating a wider variety of sizes of both soil and spaces. This variety allows for healthier growth and drainage.
Paved areas can lead to drainage and permeability problems. Permeable paving materials solve this problem by creating a firm surface for walking and parking while still allowing water to seep through. Permeable paving materials are affordable and attractive. They can also eliminate weeds growing up between paving stones!
Do your garden a favor by learning about permeability and composting!
Do you ever notice tiny black or orange flying bugs emerging from the soil of your houseplants?
This could mean you have fungus gnats. Fungus gnats are actually flies that feed on organic matter found in soil, and they can be a real problem when soil is kept moist, because the larvae of these little buggers love to chew on your plants' roots! This can cause stunting and make your houseplants susceptible to other pests and diseases.
Overwatering is a common problem for houseplants and the appearance of fungus gnats means it is time to take action.
First, do not overwater. The use of an inexpensive moisture meter (~$10) is a great way to keep your plants healthy, avoid water waste, and make life difficult for your resident fungus gnats.
Second, since fungus gnats love to eat composting plant material, keep your houseplants free of dead and dying leaves, stems and flowers. Pesticides are generally considered a bad idea in this case.
Finally, you can make your own fungus gnat trap by half-filling a bowl or wide mouthed glass with apple cider vinegar and a few drops of dish soap. Place the container near your houseplants. Adult fungus gnats will be attracted to the smell and drown. This won't eliminate the destructive larvae, but, eventually, you will halt their life cycle. This can also help get rid of fruit flies in the kitchen!
To monitor for fungus gnat larvae in your houseplants, simply put a cut piece of potato into the soil for a few days. A simple magnifying glass should help you see if there are fungus gnat larvae present. Replacing the raw potato every few days can go a long way to interrupting the fungus gnat lifecycle.
Please let me know how these methods work for you!
Over-watering container plants is surprisingly common. According to the University of California, improper irrigation is the #1 cause of plant problems.
Unfortunately, the signs of too much water look an awful lot like the signs for not enough water: yellowing, wilted leaves, stunted growth, and leaf drop are just a few of the signs for both problems.
Rather than drowning your plants, allow the soil to dry out between waterings. Don't guess! Physically look at the soil at root level to check on the roots' living conditions. An inexpensive moisture meter can be purchased at any garden supply store.
As critical as water is for good plant health, this is not a time to assume your plants are getting the water you give them. Soil structure can move water away from roots. When plants show water stress symptoms, dig down next to the root system to make sure the water is going where it is needed.
Blossom end rot is the bane of tomato growers. It starts as small brown spots on the bottom of the fruit and expands to a large, sunken brown or black leathery area.
Contrary to popular belief, calcium deficiency in the soil is rarely what causes blossom end rot.
Most soils contain plenty of calcium. There are exceptions and the only way to know for sure is with an affordable, lab-based soil test. I urge everyone to get their soil tested every few years. The information is invaluable. But back to blossom end rot.
Blossom end rot occurs when calcium and irrigation are out of balance. Calcium is an “immobile” nutrient, which means it is very difficult (i.e., uses a lot of water) to move around inside the plant after it has been absorbed. Regular, frequent irrigation during the growing season provides plants with the water they need to get calcium where they need it.
Blossom end rot conditions are made worse when salt levels are too high due to over-fertilizing. Lime can be added to provide calcium. When watering, be sure that the roots are neither dried out or saturated.
Blossom end rot can also affect summer squashes, such as zucchini. A similar problem, called bitter pit, affects apples. In either case, the rotten part can be cut out and the rest of the fruit is fine for eating.
Now you know.
Yes, I know, we've been hearing, ad nauseum, about drought lately in California. But what is it, really? According to the dictionary, it means a "prolonged period of abnormally low rainfall; a shortage of water resulting from this." No kidding, right?
According to the National Oceanic and Atmospheric Administration (NOAA), this current drought is more a matter of weather than humanity. As luck would have it, the 2011-12 El Nino meant higher ocean temperatures, which led to hotter, drier conditions in CA. A high pressure system has held those high temperatures in our area for the past 4 years. Historically, however, there has been no appreciable change since measurements were initiated in 1895.
The real problem for our local flora and fauna is that this drought has gone on as long as it has. Most significantly, old trees are showing signs of severe water stress. While our pretty annuals and productive gardens are nice to have, we can always try again next year. When working with limited water supplies, it is best to watch for symptoms of stress in your oldest and biggest plants. The UC Extension urges us all to watch for these symptoms:
Look around as you drive to work and you will see many large trees showing these signs. The problem is, a drought-stressed tree becomes more susceptible to pests and disease. As trees die, erosion increases, causing more drying out. It's a tough cycle. Rather than letting water go down the drain, collect it in a tub or bucket and give it to your local trees. You'll be happy for the shade, come August!
If your potted plants become hydrophobic, simply pouring water on them is not enough. Instead, you can revive your plants and thoroughly hydrate the soil by forcibly submerging the pot in a bucket of water until the pot no longer floats. Until the soil is saturated with water, the air pockets in the soil will make the pot float. It's pretty cool, watching all the air bubbles percolate up from your submerged pot!
Another method of rehydrating hydrophobic soil is to place the pot in a large container and pour water over the top. The water will run out of the soil but, over time, the water will eventually be absorbed.
Larger planting areas can be relieved of their hydrophobic tendency with light sprinklings of water, followed by moderate watering. Just as a slightly damp sponge will hold on to the water it touches, so will your garden soil.
No, hydrophobic does not refer to an unreasonable fear of water.
Instead, hydrophobic describes the point where soil becomes so dry that it actually repels water (read: bad for your plants). Much like a dried out sponge, when water is applied to overly dry soil, it simply rolls off and is lost.
Self-watering plant containers are an excellent way to conserve water while keeping your plants healthy.
Container gardening makes it possible to garden in small spaces or in those areas with poor soil quality. One of the biggest problems with container gardening is the need for frequent watering. This is especially true for unglazed ceramic pots, which allow a large amount of water to evaporate, and for gardeners in areas with a lot of hot, dry weather.
Self-watering plant containers feature a water reservoir below the plant medium (soil), separated by a perforated platform. The platform keeps the soil out of the water, but it allows roots access to the water supply. Being relatively sealed under the soil, water evaporation is significantly reduced, while providing your plants with all the water they need.
I found a great set of instructions for making your own self-watering plant container out of discarded 5-gallon buckets from the Maryland Extension.
Give it a try and let us know how well it works for you!
CA's drought is wrecking havoc on farms and mature trees, but grey water can be used to reduce the impact on your yard. According to UCDavis, "Greywater is untreated waste water which has not come into contact with toilet waste." This includes water collected from the shower, bath, washing machine, or sink.
You should check with your local authorities to learn about specific restrictions on the use of grey water in your area. Grey water should never be considered potable (safe to drink). Personally, I avoid using it on food crops, but it does wonders on ornamentals, lawn, and flowers without wasting fresh drinking water.
A drought is a period of drier-than-normal conditions that results in water-related problems.
According to the USGS, 2016 was the hottest on record and 2019 came in second. These are trends that can have a big impact on our gardens and landscapes.
With responsible water conservation, you can reduce water stress to plants in your yard by improving soil quality with compost and mulch and watering more frequently, but with less water. Just as a dry sponge allows water to runoff, rather than being absorbed, soil works the same way.
Another way to reduce water use is to replace your lawn with drought-tolerant plants that are better suited to your local climate. Plants have evolved over millions of years to survive and thrive in very specific environments. By growing native plants, you can take advantage of all that evolution! Contact your local CA Native Plant Society to learn how!
Urban drool is the water that runs off improperly watered lawns, carrying fertilizers, pesticides, and valuable nutrients to ground water, local streams and the ocean, causing potentially devastating bacterial and algae blooms and chemical pollution.
When watering your lawn, think of how a dry sponge absorbs less water than a damp one. Urban drool can be prevented by watering with hourly pulses of short durations that give the soil enough time to absorb the water. As the soil becomes moist, it can hold on to more water
Take a look at other hard surfaces, such as driveways, walkways, and patios. Instead of impermeable concrete, consider permeable pavers, wood chip paths, and growing strips. These breathable materials allow water to be absorbed into the soil, filtering sediments and pollutants, and allowing the water to be stored for later use by plants, rather than creating flooding, pooling, and runoff problems. These more porous surfaces also allow the soil and plant roots to breath.
If you have an area of your landscape that regularly receives excess water, you may want to consider installing a rain garden to reduce urban drool and ground water pollution.
If you see urban drool occurring at a local park or business, take a moment to reach out and let them know. They may not be aware of the problem.
You can grow a surprising amount of food in your own yard. Ask me how!
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