The Mulch Robs Nitrogen Myth

2008-08-12_Mulch

I was surprised to hear a landscape professional, at a convention I attended last weekend, repeat a common myth about wood mulch, namely that “mulch robs soil of nitrogen.” In the interest of promoting the soil boosting and water saving benefits of mulch we need to send this common misconception into the bad idea chipper/shredder.

It’s true that if you mix a lot of carbon, such as wood chips, into soil the amount of nitrogen available to plants will decrease. This is because soil organisms use nitrogen to process carbon. But this happens only if you incorporate mulch into rather than on top of soil. When you top dress your soil with mulch some nitrogen at the surface will be locked up, but this actually works to your benefit by inhibiting weed seed germination. Far from reducing nitrogen, as mulch decomposes it will actually increase the nitrogen content of your soil. This is one of the many benefits of using wood chips over inorganic mulches such as gravel.

I sometimes get asked what kind of mulch to use in a vegetable garden. I use straw since it’s inexpensive and easy to clean up at the end of the summer growing season. I wouldn’t use wood chips on vegetable or other annuals since they might get churned into the soil even though I don’t ever till or double dig. Wood chips are for perennials.

Now, my Root Simple friends, go forth and tell people that mulch does not rob the soil of nitrogen!

For more information about mulch which includes a discussion of other mulch misconceptions such as allelopathy and termites, see Washington State University Extension’s publication “Using Arborist Wood Chips as Landscape Mulch.”

Save

104 Erin Schanen the Impatient Gardener

Screen Shot 2017-06-27 at 10.11.02 AM
Listen to “104 Erin Schanen the Impatient Gardener” on Spreaker.
On the podcast this week we talk to garden blogger Erin Schanen, the Impatient Gardener. Erin lives in a small cottage in Southeastern Wisconsin. During the show we discuss some of Erin’s recent blog posts and other subjects including:

Websites: The Impatient Gardener, Impatient Gardener on Facebook and Instagram, @impatientgarden on Twitter. Special thanks to Eric of Garden Fork for introducing me to Erin!

If you’d like to leave a question for the Root Simple Podcast please call (213) 537-2591 or send an email to [email protected]. You can subscribe to our podcast in the iTunes store and on Stitcher. The theme music is by Dr. Frankenstein. A downloadable version of this podcast is here.

Save

Save

Save

Defeating Squirrels With Tech

After watching a squirrel chew up every single peach on our little tree, despite deploying yards of bird netting, I found myself pondering extreme and deadly measures. Then I found myself fantasizing about what I would do if I were Elon Musk. First, I’d give up on the mars idea. Mars is, after all, a lifeless, barren speck of dust lacking life’s essentials such as breathable air, plants, cats and Parmesan cheese. Why bother? How about, instead, turning that technical know-how towards the most important issue of our time: squirrel deterrence.

Screen Shot 2017-06-09 at 9.44.20 AM

As it turns out I’m not alone. At a Python programming conference, back in 2012, software engineer Kurt Grandis presented a research project he entitled, “Militarizing Your Backyard with Python: Computer Vision and the Squirrel Hordes.” Grandis’ motivation was a squirrel attack on his peach tree and, worse, his kid’s pumpkin patch. The full lecture details Grandis’ attempt to create a program that would differentiate between squirrels and birds and then deliver a carefully aimed blast of water at just the squirrels. It’s worth viewing in its entirety just to hear how Grandis resolves the image recognition question, “What is squirrelness?” If you’re impatient you can fast forward to the 16 minute mark for the video. Spoiler alert: it works, at first, and then the squirrels quickly learn to ignore the blasts of water.

It leaves me wondering if a scary clown strategy might work better such as it did with this bear:

Kidding aside, two Southern California biologists are using high powered lasers to dissuade ravens from attacking endangered desert tortoises. The biologists are also speculating about the possibility of “gamifying” this task by opening it up to anyone who wants to take a potshot via the internet. Which leads to my question of the day. Would you readers be interested in a gamified laser squirrel shoot in the Root Simple backyard? Time to learn Python!

Save

Save

Reader Favorite California Native: Ceanothus

Image: Kousvet

Ceanothus thyrsyflorus ‘Repens.’ Image: Kousvet

When I asked readers for native plant favorites not included in our short list of six favorites, we had a few votes for Ceanothus a.k.a California lilac, wild lilac, and soap bush. In case you’re not familiar with this stunning plant, it’s a family of shrubs and ground covers that have dark green leaves and deep purple or sometimes white flowers.

The reason I didn’t include it is that it didn’t meet my “bombproof” criteria, at least in our garden. It’s one of the many plants we’ve managed to kill. It’s true that once you get it going, other than yearly pruning, you can retire to the nearest bar and rest on your gardening laurels. But getting it established can be tricky. The most common mistake is over-watering during the summer months and planting in overly fertile soil. We didn’t over-water, so how we manged to kill three of them is a Root Simple gardening mystery.

That said, many of our neighbors have had no problems with Ceanothus. If you have a well drained sunny spot, it’s a good bet. I’m particularly fond of the short sprawling varieties such as Ceanothus thyrsiflorus repens.

The UC Davis Arboretum keeps a list of “All Star” plants that includes Ceanothus ‘Concha’ and Ceanothus maritimus ‘Valley Violet’. You can find more Ceanothus varieties on the Las Pilitas Nursery website.

By United States Fish and Wildlife Service, Sherburne National Wildlife Refuge: Ceanothus americanus L., Public Domain, https://commons.wikimedia.org/w/index.php?curid=666534

Ceanothus americanus Image: United States Fish and Wildlife Service.

Our East Coast readers can plant Ceanothus americanus, a plant used by early settlers as a substitute for British tea.

Save

Save

Top Six California Native Plant Performers

whitesageBetween Kelly’s aortic episode and my mom’s passing, gardening took a back seat during the past six months. As a result, our yard doesn’t exactly look like Versailles. I’m thankful Kelly had the foresight, before our family emergencies, to reduce the amount of fussy annuals and increase the number of California native plants. While no garden is ever “zero maintenance,” some plants, such as these six California natives can survive with less care. This is, by no means, an exhaustive list but just a few of the plants that have been successful in our garden. Your results may vary.

1. White sage (Salvia apiana)
Kelly and I both love this plant. It’s aromatic, useful as a spice and incense and both honeybees and native bees love it. There’s a lot of unethical foraging going on in our local wilderness areas to supply the Silver Lake shamans with their white sage smudge sticks. Grow white sage in your yard and you can roll your own smudge sticks. You can also put a leaf in your water bottle for a refreshing drink. Each fall it should be pruned back to avoid legginess.

IMG_79742. Cleveland Sage (Salvia clevelandii)
This one is becoming as popular with house flippers as Mexican sage (Salvia leucantha) was back in the aughts. It’s easy to see why. Salvia clevelandii is pretty and grows like a weed.

blacksage3. Black Sage (Salvia mellifera)
Our black sage is doing so well that it might just swallow the entire backyard. This is good as we haven’t a clue what to do with the part of the yard it occupies. Sprawl on Salvia mellifera!

gigantium4. St. Catherine’s Lace (Eriogonum giganteum)
Note the “giganteum” in the scientific name for this member of the buckwheat family. Give this baby some room. Ours is doing well in partial shade.

toyonsmall5. Toyon (Heteromeles arbutitolia)
This treeish native stared the drought in the face and laughed. We planted it in the neighbor’s yard where it got cut down accidentally. A year later it had grown back to its former glory. Birds love the little red berries, which can be dried for a not very exciting human snack.

coyotebush6. Coyote Bush (Baccharis pilularis)
A hellstrip favorite, this bright green ground cover can keep native plant phobic neighbors happy and withstand some late night trampling from Silver Lake shamans on their way back from Coachella.

A warning here: all of these plants are large. Watch your spacing when you plant them and don’t put them too close together.

While we’re talking about native plants, our friend David Newsom has launched an important new initiative called the Wild Yards Project to encourage people to “restore native plant and animal habitat, one yard at a time, using native plants and trees wherever you live.” Note that this project is for people all over the US, not just in California. We’re going to have him on the podcast to discuss the project in depth, but before we do that I’d like all of you to join the Wild Yards Facebook and Instagram. David would especially like people to post before and after photos of their gardens.

Do you have some favorite California natives that should be included on our “top performers” list?

Save