In the last few years there has been an interest in “no till” methods of gardening that propose numerous benefits such as increased yields, less physical work, and much healthier soil cited as reasons we should stop digging our soils. However I wonder if this method of growing is really suited to the environs of desert areas? Here are some thoughts of mine on the issue.

Let's start with what “no till” growing is, and how does one go about doing it.

There is more than one way to accomplish a "no-till" garden but the most commonly advocated method is sheet mulching. (It goes by many names.) As the name suggests, the soil is not dug in preparation for growing food or ornamental plants but rather the top of the soil is regularly amended with organic matter which works its way down into the soil to feed the roots of the plants from above.  To start a new growing bed using this method, a layer of cardboard is put over the surface of the ground in order to suppress existing weeds. Then a deep layer of well-rotted compost is laid over the top and crops are grown in this. Plants are mulched to retain moisture, and over time the cardboard rots and worms take the compost down into the native soil. This is considered to be closer to how plants and soils interact in the natural world.

By contrast, hand digging or rototilling disturbs the natural profile of the soil by destroying earthworm burrows and bringing the natural and beneficial mycorrhizae to the surface where ultraviolet light and drying conditions kill these fungi. It also interferes with the natural drainage of soil so dug soils drain poorly compared to the compost in no till beds and soil loss by wind erosion is increased.

There is a lot to be said in favor of the no till method. However, is a no-till method like sheet mulching suitable for desert situations with a very low natural rainfall? Most of those who advocate this method of growing and have the greatest success live in high rainfall areas where precipitation is regular throughout the year, and often the rainfall each month is as much as our desert area receives in a year! We also have very dry air with a relative humidity often less than 10%, with frequent, quite strong, drying winds. Our natural vegetation is sparse and prickly as a result of the climate, and things decompose very slowly.

Beneficial to the soil as “no till” might be, some arguments in favor do not hold up in our area. Supposedly it is less labor intensive since one does not dig, but to produce the amounts of compost needed in our area for this method to work, one either has to constantly turn compost heaps, or else buy compost in bulk (assuming that you can find a local source), pay for it to be delivered and then barrow it to the growing area! Our environment makes it hard to even acquire something to make compost from in sufficient amounts.

Then there is the tremendous water usage, both for keeping one's compost heap working and then keeping the applied compost damp enough for these benefits to occur in the garden. Everything dries quickly in our wind, sun, and heat.

Mulch such as wood chips takes a long time to rot down in the desert but without some protection our desert winds can certainly remove loose topsoil. In my experience they are equally efficient at removing the finer particles of mulch, leaving only the sticks behind. Often I have put a deep layer of shredded leaves around plants and on top of the drip irrigation tubing but this fine mulch, far from rotting down or being taken into the soil by accommodating earthworms has rapidly vanished into the next county during our high wind events. This does not happen so much if the mulch surface is kept wet, but can we afford to use that much water when facing a serious drought?

When digging I always incorporate generous amounts of compost or manure or any remaining surface mulch into the ground where it will not get blown away and will be in close proximity to the roots of my crops. I dig in winter when earthworms are very deep in the soil but by spring I have an extremely healthy population. 

In many places in the desert where the soils are sandy and alkaline, earthworms are a rarity - if present at all, so in these cases the downward movement of organic matter placed on the surface is not likely to happen for several seasons, and indeed where I have raked several year's accumulation of leaves from under shrubs, even the bottom layer hardly shows any evidence of the leaves breaking down.

No till's proponents admit that slugs and snails are common problems in the compost-grown vegetables, although I doubt whether that would be much of a problem here, but I did mulch heavily with straw one year and consequently had the worst European earwig infestation that I have ever experienced.

Our desert soils certainly need a lot of help in the form of organic matter if they are to produce crops, but it is difficult to know which is the best way to achieve that. As with most horticultural endeavors there are pros and cons to both methods but it pays to think of different options, and perhaps do a trial bed before embarking either method on a large scale.

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Editor's note: Another consideration is the population of weeds present. At least in the Owens Valley, our perennial weeds, especially Bermudagrass, emerge through the cardboard layer quickly since it is insufficient to stop them. A gardener would have to eliminate perennial weeds first. Our wind also brings in fresh seeds of wind-dispersed annual weeds that grow well in the rich, organic layer.

It's spring again! Time to start preparing your garden for planting. Read on for some tips to make this year's garden your most successful yet.

The first step in planning a garden is to select a site and amend the soil. Pick a site with good drainage, full sun, access to water, and low traffic. Leave walking room between rows. Never walk on the soil in your garden beds. 

Prepare your soil three weeks before you plan to plant. Weed your garden and turn under any cover crops, if you grew any. You will want to loosen the soil 10-12” deep and break up big clods of soil to make it easy for the roots to grow. Do not till very dry or wet soil; soil should be dryish but still able to loosely clump with some effort. You can learn how to double dig your soil by watching the video on YouTube made by our own Master Gardeners: https://youtu.be/KHvgDUd0VS8 .

Next, you can mix in amendments if needed. Soils throughout most of Inyo and Mono Counties are derived from sources in the Sierra. Most soils in our area are well-drained, do not have accumulated salts, and have a good pH for growing plants. However, some communities in our area, such as Chalfant, have soil that is derived from other mountain sources producing alkaline soils that require amending with sulfur before planting. See our local soils page for more information about your local soil.: https://ucanr.edu/sites/newinyomonomg/Eastern_Sierra_Gardening/Soil/Your_Local_Soil_487/ 

Garden beds should be amended with compost annually. That is especially true here because our desert soils drain water excessively and hold few nutrients. Organic matter, such as compost, improves both the fertility and the texture of the soil. Inorganic fertilizers aim to feed plants and do not affect tilth or the holding capacity of soil. Mix 1-2” of compost or high-quality organic material into the top 4” of your soil with a hoe or a spade. If using manure, make sure it is fully composted. After mixing in the compost, water the bed evenly. Then, let it rest until planting. 

If you have terrible soil, you can make raised beds and bring in external soil. Soil in raised beds should be composed of about ½ topsoil and ½ organic matter (mostly compost) by volume. No need to be exact! For more information on raised gardens, visit our website: https://ucanr.edu/sites/newinyomonomg/Eastern_Sierra_Gardening/Vegetables/Raised_Beds/

For best results, many plants require an additional fertilizer. The three primary nutrients plants need are nitrogen, phosphorus, and potassium.  Too much fertilizer can affect growth, so only add enough to meet the feeding needs of your plants so be sure to carefully follow directions for application.

Have an irrigation plan before planting. Soil needs to remain evenly moist during germination and throughout the growing season. Soil will dry out to a depth of a few inches in the sun. Below that, only plants can remove the moisture. Insert your finger into the soil to determine if the soil is moist or dry and adjust your watering accordingly. For water efficiency, irrigate at the base of the plants early in the morning or late in the evening. Drip irrigation is best. For information on irrigation, visit our website: https://ucanr.edu/sites/newinyomonomg/Eastern_Sierra_Gardening/Irrigation/

Remove weeds as they arise because they compete with your plants for resources. Usually, weeds can be easily controlled by pulling. If not, you can hoe or possibly use herbicides. Be extremely careful when spraying. Never spray when it is windy because most herbicides will kill your plants too. Always read the label and follow the directions when using herbicides. Most gardeners in our area are able to control their weeds with pulling and hoeing, however.

Now you are ready to plant!

Start warm season crops indoors six weeks before planting. You will want to plant as soon as possible for the longest growing season but after the danger of frost, since frost can kill your plants. As a general rule of thumb, transplant when the soil 4 inches deep is 60 degrees at 10 am.

In Bishop, the last frost occurs after May 5 50% of the time and after May 14 25% of the time. Most years the soil is warm enough to transplant well before the end of frost season.

If there is a frost after you plant, protect your plants by covering them. For more information on starting your vegetable garden, visit our website: https://ucanr.edu/sites/newinyomonomg/Eastern_Sierra_Gardening/Vegetables/Getting_Started/

Have fun with your new garden!

The first week of December is California Healthy Soils Week. To help "celebrate" the occasion I was asked to give a lecture on some tips to keep your garden soil healthy. If you're the type that likes to watch videos, then you can watch the recording. (It's about 1 hour including the questions at the end.)

If you're like me and like to get the short, bullet-point version, here it is.

Dustin's Healthy Soil Tips:

• Know your native soil (Try this link!)
• Make permanent paths
• Treat beds like beds: don't stand or walk in them and keep them covered—with mulch
• Add organic materials like compost
• Rotate crops; be sure to include cover crops
• Till gently; here's an article to learn more

Note: Inyo-Mono Master Gardeners who watch the video can receive 1 hour continuing education credit.

It's now October so that means that we're now in the time of year where we start to wind down our gardens for the season. If you're at all like me and refuse to plan for the eventual coming cold weather by pulling out plants, a killing frost will force the matter.

For most of the Eastern Sierra, at least places where gardening is feasible, October brings us our first frost of the season.

A tomato vine with freeze damage that occurred in Bishop on October 10, 2017.

I am often asked about first and last frost dates for various communities. The good news is I have that information. The bad news is that there is wide variability in the actual date. That means it's important to keep an eye on the weather forecast.

Average First Frost Dates

There are two ways to think about frost dates. Here is the first and conceptually easiest to understand: Average first frost date along with an estimate of the spread of when that might happen. The table below shows the average first frost of fall and a range of dates that shows where there is about a 70% chance the the real frost date will fall.

First Fall Frost Dates

Big Pine is about the same average date as Bishop—maybe a little later—but it varies much more. We don't have any data, but that's a observation from gardeners there. 

It's also worth noting that the data for Topaz Lake isn't that great, and the station isn't in the best location for predicting effects to your garden. That said, the whole area has a lot of variation every year, making predictions hard. This data is a good place to start.

A Probability Approach

The other way to look at frosts is to consider some level of risk that you are comfortable and then check which date corresponds with that risk level for your location. The Western Regional Climate Center has extensive data and risk projections for many locations in California. (Here is the data: https://wrcc.dri.edu/summary/Climsmcca.html )

Below is an example for Bishop, California.

1. Follow the link to WRCC's page
2. Choose a station from the list
3. On the left side you will see various reports. Fall 'Freeze' Probability will generate a report like above. Scroll down some to see it. It's under the Temperature heading.

Final Thoughts