- Author: Alison Collin
This year I was determined to create the “model garden” that I have long dreamed about, but those dreams of neat, weed-free rows of vegetables, trees hanging with fruit, and armfuls of flowers are far from being fulfilled. In fact, I have had a garden of pestilence and disease on a scale that I have never faced before.
In accordance with modern ideas of “gardening with nature” last fall, I spread compost and rotted manure in liberal quantities. I left leaves on the ground in order to afford some protection to plants and beneficial insects in our high desert location. This resulted in my seeing the first grasshopper – a whopper – on January 26, followed shortly after that, by clouds of leaf-hoppers erupting from some mulch that I had put over my strawberry plants and blackberry roots. It was not apparent that the beneficial insects gained the same advantage.
Carefully nurtured spring transplants, often consisting of rare or unusual species were rapidly chewed to stubs before I had managed to get any protection set up. As the weather warmed a large crop of fence lizards appeared, and it gave me immense satisfaction to see grasshopper legs protruding from their mouths. Nothing seemed to eat the leaf-hoppers and spraying with horticultural oil failed to reduce their numbers.
The blossom on the fruit trees was a joy to behold until early May when a frost damaged the flowers and destroyed the early fruit set, so no plums, peaches, or cherries this year, and only a few pears. Potato shoots were frosted and a tomato which was covered with two layers of insulating cloth was cut to the ground.
I thought how pretty the gray foliage of the California poppies looked in the pollinator garden before I realized that they were suffering from a hefty dose of powdery mildew which also severely affected all the larkspur and older roses, although the modern hybrids were largely resistant. This problem, which likes dry conditions affected only one side of the house, while the better irrigated areas of fruit trees and vegetables showed no signs of it.
By early June it became evident that our irrigation system had problems. With drip irrigation, much of it is out of sight, and it is not always apparent when things go wrong. I lifted the lid of the irrigation vault and found it full of water and a mass of fibrous roots from the nearby grape vine which was growing vigorously. This led to a redo of the vault and installation of new valves. The grape immediately took umbrage at the disturbance, and the loss of roots and water and went into a state of shock; the leaves already much damaged by leaf hoppers crisped and the few bunches of grapes stopped swelling. Within a couple of weeks the vault had been invaded by a ground squirrel which had managed to follow a pipe into the vault and thrown soil all over the valves.
Through all this my usually trusty potatoes stopped growing and the foliage turned yellow and looked awful. I left them for a month to see if they would improve then began to dig them up. Each plant had a cluster of small potatoes with many enlarged lenticels - indicative of too much water. There were a lot of symphylans present so I suspect that they had damaged the roots or tubers somehow. The carrot patch had also received too much water so that the well grown ones have split from crown to root tip.
Low growing fruits – strawberries, figs, raspberries and blackberries began to disappear into the gut of the ground squirrel and various birds but netting the awkward shapes of all these plants was challenging and did not solve the problem. Next, a rat discovered the joy of eating grapes and most of the remaining bunches became bare stalks – a reminder of what could have been.
The annual thrips infestation of onions began early and I only managed partial control with insecticidal soap sprays. Luckily the onions don't look too bad. Rhubarb leaves were skeletonized by European earwigs, which also took a shine to the foliage of a precious new dahlia plant.
I tried to grow fillet French beans for the first time, but they very quickly became infected with a virus, some almost as soon as they got their first true leaves. Yesterday I noticed that my best Japanese eggplant is laced with holes from flea beetles and there are now large yellow patches on the newer leaves, possibly caused by some disease.
Ants have dominated every corner of the garden and one variety has taken to building mounds of organic matter over the crowns of the strawberry plants. The zucchini was taken over by one species of large ant. They were particularly drawn to the flowers, and although they prevented the squash bees from getting close, the ant must have pollinated the flowers since we had an excellent crop, and only one squash bug all summer! However, they have now started to farm aphids on this plant and also the nearby cucumbers which became so badly affected by sooty mold that I had to dispose of them. As it happens that is not such a loss since many of the cucumbers have been extremely bitter – a problem that I have never had before.
In the fourteen years that I have gardened in Bishop I have had very few serious pests or diseases, of any sort, apart from the ever present Bermudagrass, spotted spurge, and purslane which seem minor compared to the problems that this year has brought.
On the brighter side: My tomatoes have done well and stayed disease free so far, the pear tree seems to no longer be infected with blister mites or fireblight, there were few aphids on the peach trees and cherry and all the fruit trees have put a lot of energy into growth rather than fruiting, so I have had a restful summer, well away from the preserving pan, although now I have to get the pole pruner out!
You never know what's in store for one's garden. I hope that I will achieve my “model garden” next year...
- Author: Ryan Daugherty
Why Lawns Go Full Drama Queen During Droughts
Imagine being stuck in a sauna without a drink of water.
That's your lawn during extreme dry heat. Here are the main culprits:
- Lack of Water: Duh. When it's hot outside, your lawn needs more water. But with water restrictions and the general annoyance of hauling a hose around, many lawns just don't get enough.
- Soil Compaction: If your soil is as hard as a rock, water won't penetrate it. Roots can't grow, and your grass will starve for water.
- Poor Root System: Grass with shallow roots is like a teenager with a bad Wi-Fi connection—constantly in distress. Deep roots are essential for tapping into moisture reserves, but hot, dry conditions can prevent roots from growing deep.
Common Lawncare Blunders in the Heat of the Moment
We all make mistakes, but when it comes to lawn care in extreme heat, these common goofs can turn your yard into a crispy nightmare.
- Overwatering: Believe it or not, you can overdo it. Too much water can lead to shallow roots and fungal diseases. Plus, if water just sits on the surface, it can evaporate before it even reaches the roots.
- Underwatering: On the flip side, skimping on water is a sure way to send your lawn into a death spiral. Consistency is key, folks!
- Mowing Too Low: A short tight lawn might look neat, but it's a death sentence during drought. Longer grass shades the soil, keeping it cooler and reducing evaporation.
- Fertilizing During Drought: Fertilizing during extreme heat can burn your grass and make it extra crispy.
- Ignoring Soil Health: If your soil is more barren than a Monday morning coffee pot, your grass won't thrive. Healthy soil retains moisture better and provides essential nutrients.
Strategies to Survive the Lawn-pocalypse
Alright, enough with the doom and gloom.
Here's how to be the Lawn Whisperer and keep your yard looking fabulous, even when Mother Nature is throwing a tantrum.
- Water Wisely: Water deeply and infrequently. Aim for early morning watering sessions to reduce evaporation. If you have an automatic sprinkler system, set the times so that your sprinkler cycles are ending right as the sun comes up.
- Aerate Your Lawn: Give your grass some breathing room by aerating your lawn. This reduces soil compaction and allows water to penetrate deeper. It's like giving your lawn a spa day. Try not to do it when your lawn is stressed, spring and fall are best.
- Mow High: Set your mower blade to the highest setting. Taller grass shades the soil, retains moisture, and promotes deeper root growth. Your lawn will look thick and lush in no time. Like aeration you should avoid mowing spots of stressed grass, it's only going to damage the lawn more.
- Soil Care: Improve your soil's health by adding organic matter like compost. Healthy soil holds onto water better and provides essential nutrients to your grass.
- Avoid Fertilizing During Drought: Hold off on the fertilizer until conditions improve. Focus on watering and soil care instead. When the weather cools down, your lawn will be ready for a nutrient boost.
- Monitor and Adjust: Keep an eye on your lawn's condition and adjust your care routine as needed.
- When all else fails let it go dormant. It may not look great but the reason your lawn looks brown and crispy is because it's going dormant and protecting the crown to come back when conditions improve. If you can't provide enough water to consistently keep the grass healthy it's better in the long run to let it go dormant rather than to provide inconsistent health that drains resources that the grass will need to recover later. Grass can survive for weeks in that state but if you're going to let it go dormant, provide sufficient water every two weeks or so to keep the roots from drying out completely.
You may notice a shift in turf species growing in your lawn after a spell of drought and dormancy due to differences in stress tolerance, especially for a prolonged drought.
Embrace the Chaos?
Let's be real—sometimes, despite your best efforts, your lawn might still look like it's auditioning for a zombie movie. And that's okay, droughts are tough!
Remember, the key to surviving a Lawn-pocalypse is to stay calm. The lawn could just be responding to environmental stress, but with a little TLC and some strategic care, you can help your lawn bounce back.
Keep hydrated (both you and your lawn), and maybe learn to love a little bit of brown.
- Author: Dustin W Blakey
I know you've seen them. Little caps on the end of vertical irrigation pipe that can be adjusted to control flow with a twist (or screwdriver). They are called flood bubblers and are used widely in the Eastern Sierra to deliver water to woody plants outside of a lawn sprinkler system.
Unfortunately, I see more tree problems caused by this type of irrigation than any other single cause of tree death in our area. Many dead or sick trees in our area have been irrigated (insufficiently) by flood bubblers.
What are bubblers for?
Bubblers have a few important uses and benefits. They are good at watering young trees during establishment since the water is concentrated near the root ball. In the right types of soil, they can also be good at watering shrub beds or large tree wells if the output can exceed the soil's infiltration rate. They flood the soil with water. When there is a berm or wall around the bed, and if you can fill it, bubblers are a fine choice.
In general, as a source of water there really is no problem with their use. They are cheap and low maintenance. The lack of spray helps to prevent water lost to evaporation while they are running.
The issue is how we use them locally over the long haul.
Bubblers are not drip systems
The purpose of a bubbler-type emitter is to deliver a high output rate of water to a concentrated area, like a single, young tree. I often see one bubbler per tree. The shape of the bubbler takes away some of the kinetic energy of the flow and allows a gentle flood that hopefully will not disturb or erode the soil.
Many bubblers here are used as a substitute for a drip emitter. This is the beginning of the problem. Bubblers are designed to deliver about 2 gallons per minute, whereas a single drip emitter is usually closer to ½ gallon per hour.
Instead of filling the root zone with water, only a small amount is delivered frequently, often several times a week in that same small spot. In practice I mostly see bubblers used to irrigate trees and shrubs outside of a lawn.
There are two issues that arise with this practice:
- Trees grow! And as they grow their water requirements and root area increase. You should be aiming to water the whole area under a tree, not just at the base. While it's possible to crank up the flow to deliver more water, this doesn't solve the problem of having an insufficient area irrigated under the tree.
- Most of the Eastern Sierra has coarse, well-drained soils. In our soils, the frequent, low-volume application of water only saturates a very small area much smaller than is needed. This constrains a tree's root system and eventually leads to chronic stress.
Drip systems are designed to deliver a predictable, slow rate amount of water from each emitter on the line. The key word is each. Drip lines usually incorporate many emitters to deliver water slowly to the root zone. A properly designed drip or microsprinkler system can irrigate the entire region that needs water.
Perhaps if additional bubblers are added to a row of trees along with more output from each bubbler, things wouldn't be too bad. This, however, is not how they are used.
What to do if you already have bubblers
It's not the end of the world if you have bubblers in your landscape, as long as you don't wait until your trees or shrubs begin to die to address the situation. The first step is to recognize that flood bubblers are not drip emitters.
The simplest solutions involve swapping the bubbler head with something different.
An easy, but perhaps less water-efficient, change you could make to your system would be to replace the bubblers with spray heads after the trees are established. Spray heads come in a variety of patterns, and some can be adjusted. These are an easy way to increase the coverage area. The will heads have the same threading as your bubblers. As long as you can deliver enough flow and pressure, this conversion works well. Of course, you'll need to alter your irrigation schedule.
Because you will now be hitting the trunks with water, which is less than ideal, adjust your system to deliver more water each irrigation, but less frequently. This will allow bark to dry.
If the line of plants is long or irregular, another approach could be to replace the bubblers with drip conversion heads. These will supply several connection points for ¼” drip line. At the ends of each you can either have drip emitters or microsprinklers. If you only have a few trees consider installing a clever set up called a T.R.I.C. (Tree ring irrigation contraption).
Either way, the idea is that you switch to covering a larger area with more water but less frequently.
Alternatively, you could open up the bubblers' nozzles to allow more output, assuming you can deliver enough flow to overcome the rapid water drainage of our soils and cover the root area. That may require installing some sort of containment. In most situations, I'm skeptical this can work.
In landscape beds and containers, especially in commercial situations, bubblers make some sense. The area to irrigate is usually small, and there is almost always some sort of impermeable “wall” around the bed that confines growth. This is likely their best use case. When there is pavement covering a substantial part of a tree's root system, such as a parking lot, this may be your only means of providing enough water.
Final thoughts
In theory, there is nothing wrong with flood bubblers when they are used as designed. Our local issues arise when we try to use them as an alternative to a real drip system in coarse, desert soils on mature trees...forever.
To determine how much water to provide trees and shrubs in the Owens Valley, there is a handy fact sheet available at this link. Your goal with tree and shrub irrigation should be to fill the root zone with water, but no more than, and replenish it when about half that water is used by the plants.
Don't assume that because of the prevalence of flood bubblers in our area that this is the best way to irrigate landscape trees. It's a useful tool for young trees and containers, but not usually enough for larger, established trees.
If you have questions about replacing your bubblers, contact the Inyo-Mono Master Gardeners at immg@ucanr.edu.
- Author: Ryan Daugherty
I was dealing with a gopher problem in a lawn awhile back and I came across another turfgrass pest that you may or may not be familiar with; a chafer beetle.
These white grubs are the immature larval form of a chafer beetle.
Here in California we deal mainly with the masked chafer (Cyclocephala spp.). Mature grubs have white or cream colored, C-shaped bodies, six legs on their upper half, and a chestnut brown head. They can be confused with the somewhat smaller black turfgrass ataenius larvae (Ataenius spretulus). To identify the difference between the two, look at the tip of the abdomen (the opposite end from the head) for the arrangement of bristles and overall anatomy, we call this the raster pattern. A chafer's raster will have a transverse anal slit with an indistinct pattern of bristles all over. An ataenius will have two distinct pad-like structures on the tip of the anal slit.
The chafer grubs feed on turf roots in early spring then stop around May to pupate with adults emerging around June to mate. Adults actually have non-functional mouthparts and so do not cause feeding damage, in fact they die of starvation shortly after laying eggs. Adults are about 3/4 inches long with golden brown bodies and they emerge during the night with a strong attraction to light. If you see adults during the summer, eggs are likely being laid in your grass. Eggs hatch around August and the grubs do most of their damage in September and October before moving deeper into the soil to overwinter until the spring.
Damage looks like drought symptoms in turf: brown, blueish, or gray spots, brittle straw colored grass, thinning stands, and footprinting. These symptoms are from the extensive root feeding of the grubs as the grass loses much of its ability to take up water. You may also see vertebrate feeding from birds or skunks that can cause further damage digging for the grubs. Spots of affected turf may be small, only being a foot or two across but may combine with other spots to form large sections of damaged turf. A hallmark of grub damage is that damaged turf can be peeled back from the soil like a carpet, due to the turf having no roots.
Insect damage in home lawns is rarer than you might think, with abiotic problems like poor irrigation, mowing, or fertility practices being a more likely culprit for a struggling lawn. If there is an insect pest make sure you correctly identify the insect before intervening with any control measures. Also remember that the presence of a pest doesn't always necessitate control. A healthy lawn can withstand damage from a few grubs and a robust lawn is always the best defense against pest damage.
Damaged turf can be helped by irrigating more frequently to keep soil moist around the lawns now shallow roots. Lawn aeration can also kill segments of grub populations. Reserve any kind of chemical intervention until you see 6 or more grubs per square foot. Several insecticides are available on the market for chafers or white grub control just look at the label. UC IPM has a page dedicated to masked chafers, but keep in mind the pesticides recommended there are for professionals.
Always read and understand the label of any pesticide you intend to use. Be careful to refrain from applying insecticides (especially broad spectrum) if there are flowering plants in and around the lawn; this includes weeds like clover or dandelions as it can harm beneficial insects like pollinators that may come into contact with them.
- Author: Ryan Daugherty
I recently helped one of our local student gardens install a drip irrigation system in some raised beds. During the installation, I had to explain why we were using ½” tubing for most of our system instead of ¼”. Some believed that using the smaller tubing would give us better pressure, like putting your thumb over the mouth of a garden hose. I explained why this would actually result in less pressure and worse water distribution throughout our system. This misconception is common, so I thought I'd discuss it here.
If you think there's no way I'm about to talk physics in a garden blog, prepare to be amazed!
First, a review. Friction is the force that opposes the sliding or rolling of one solid object over another. There are a few different types of friction, but the one most relevant to our irrigation lines is kinetic friction.
Kinetic friction is the force that opposes the movement of two objects in contact while in motion. Think of it like using the brakes on a bicycle: when you pull on the brake lever, the brake pads contact the wheel, and the kinetic friction between the pads and the wheel opposes the wheel's forward motion, eventually stopping the bike. As water moves through our irrigation lines, it is in contact with the inside of the tubing. The kinetic friction between the water and the tubing surface opposes the water's forward motion, resulting in a loss of pressure. In irrigation lingo, we call this "pressure loss from friction" or just "friction loss."
If you could see a cross-section of your tubing while water was running through it, you wouldn't see a solid cylinder of water. Instead, it's more turbulent, with empty space, bubbles, and vortices. If the amount of water moving through the line remains constant and we decrease our tubing diameter, that empty space shrinks, and more water comes into contact with the sides of the tubing. More surface area of the water in contact with more surface area of the tubing generates more friction, resulting in more pressure loss.
Like tapping the brakes on a bicycle, there isn't much friction generated when it's just your thumb at the end of a garden hose. The real pressure loss comes from consistent friction over distance, like holding the brakes down until the bike stops. Multiply even a small amount of friction over any real distance, and you're looking at significant pressure loss.
In response to this, drip irrigation experts developed “rules” or guidelines for drip irrigation. For ¼” tubing, we call it the 30/30 rule: no more than 30 feet in any given run of ¼” line, drawing no more than 30 gallons per hour (GPH). More than 30 feet generates too much friction loss, and hydraulically only so much water can move through any given volume of tubing, hence 30 GPH. For ½” tubing, it's the 200/200 rule, for ¾” it's 480/480, and so on. As our system grows in length and demand, our tubing diameter has to increase accordingly.
If we don't match our system to the length and demand, we risk poor distribution uniformity. We might have to overwater or underwater one part of our garden to properly water another, leading to water waste and poor plant health. For most home landscapes, 1/2" tubing works well since we seldom run more than 200 feet on a single line.
These principles are simple but powerful, and by understanding them, you can make more thoughtful decisions in the design of your drip systems to get the most out of them.
