All posts by Jan Nelson

I am a landscape designer and consultant in the Santa Cruz mountains in California. I write a weekly gardening column for the Press Banner newspaper. I am also a Calif. Advanced Certified Nursery Professional and managed The Plantworks Nursery in Ben Lomond, Ca. for 20 years.
Design trends

What’s Sheet Mulching?

Can you believe this yard was solid ivy, blackberry and vinca not that long ago?

Boy, was I impressed. Not long ago I was at a garden to consult with a new client on some upgrades they envisioned for their property. I love to meet new gardeners and give them “my two cents worth”. Well this homeowner had Googled how to get rid of her entire yard full of ivy. It also had a little vinca and blackberry thrown in just to make it interesting. Her success is story of inspiration. If she can do it so can you.

Because the ground is still moist from recent rains and summer is coming, this is the perfect time to get rid of an old lawn or invasive ground covers.

This simple technique eliminates a lawn or invasive ground covers by smothering them with layers of compost and renewable materials. Here’s how to do it:

  1. Mow the lawn down to 1-2 inches, leave the clippings in place and soak with a hose if the soil is dry. If dealing
    with ivy, blackberries or vinca remove as much of the top growth as you can.
  2. Flag the locations of sprinkler heads you will be keeping for your new plantings and cap off the ones you won’t
    need if there is an irrigation system in this area.
  3. Add an inch of compost to speed up the decay of the grass. If your lawn borders a driveway, path or sidewalk
    you’ll have to remove about 3 inches of soil along these edges and back about 8-12 inches so that the new mulch doesn’t slide off into the sidewalk. This is not necessary with ivy.
  4. Put down 2-3 layers of newspaper or one layer of cardboard overlapping the edges by 6-8 inches to prevent regrowth at the edges. You can buy recycled cardboard in rolls for larger projects or find your own at appliance or bicycle stores. Wet the cardboard or newspapers to keep them in place as you go along. It’s best to use cardboard or newspaper that will break down quicker. Don’t use plastic sheeting because water and air cannot penetrate it.
  5. Add a 3 inch layer of mulch such as wood chips from a tree trimming company. You can use compost, straw or
    shredded plant material. If you have bermuda grass or other weeds like oxalis you will need to layer about 8 inches of mulch to smother them.
  6. Water thoroughly.

If you can wait a month or more to let the decomposition process get going so much the better. If you just can’t wait you can begin planting now by scraping away the mulch and poking a hole in the cardboard or newspaper where the plant is to go. Then add some compost to help the new plant become established. Be sure to plant high enough to prevent crown rot and keep the mulch a couple inches away from the stem. The top of the root ball should be 1-2 inches above the soil and just below the mulch.

Modify the sprinkler to drip and remember to adjust your irrigation system run times to accommodate your new plantings.

This is a basic “lasagna” method for lawn removal. If you are planning to replant with water smart grasses you would choose finer composted mulch instead of bark chips. Either way the process works on the same concept as a compost pile. As the lawn dies from lack of light, it decomposes with the activity of beneficial worms, insects and microorganisms coming up from the soil and doing their job to break down the nitrogen and carbon in the sheet-mulch layers. It’s a win-win situation for the environment and your water bill.

This yard use to have an old lawn before it was sheet mulched away.

Water conservation starts with losing or reducing the thirsty traditional lawn and reducing irrigation. Transform your landscape into a resilient garden that not only saves water but acts to build the earth into a living sponge that harnesses rainwater and replenishes the aquifer at the same time. Attracting wildlife to your new beautiful garden is a bonus.

Design trends

Why Mulch?

You can get results like this garden with organic mulch.

Mulch is not a very exciting subject but it sure is important to the health and productivity of your garden.

It’s great that everyone has accepted the value of covering the soil with organic mulch. Organic mulches- such as bark chips, treated sawdust, straw or even grass clippings keep plant roots cool, encourage earthworms and other beneficial organisms, conserve soil moisture, combat weed growth and protect the soil from erosion.

But is there an organic mulch that is better than another?

There are many types of mulch available. Nurseries sell different types of mulch in bags, building supply yards carry everything from bark nuggets in different sizes to treated sawdust to chipped wood and even shredded redwood bark. Shredded redwood bark, also called gorilla hair, does nothing for the health of your soil, however. If you have a very steep slope you may have to go with this type of mulch but that’s the only time I can recommend it. It will cling to a hillside without washing down in winter rains but treated sawdust would also work for this type of terrain and is much better for soil health.

Of all the types of organic mulches out there, recent studies have shown that ramial bark chips are one of the best mulches to improve soil health. Ramial chips come from trees and brush with branches up to about 3 inches in diameter- with or without leaves. These chips contain a high percentage of thin young bark and young wood. This is what makes them so valuable to the garden. Young wood is a trees factory for producing protein, glucose, fructose, lignin and polysaccharides. It’s an important source of nutrients for living things at all levels according to a study by soil scientists, G.Lemieux and R.A.Lapointe. You can obtain these kind of chips free from tree trimming companies who are probably working nearby chipping roadside brush for PG&E. Any disease in the chips doesn’t transfer to healthy plant roots, as long as you don’t dig the chips into the soil. You can also buy clean chips from landscape supply yards or in convenient bags from nurseries.

Newly installed, this garden will thrive with organic mulch.

Make sure you get fresh mulch spread over your garden plants soon. It’s that time of year to mulch existing perennials, shrubs and trees.Besides the mulches mentioned above a little chicken manure is good worked into the veggie garden but composted horse manure works better as a mulch for the rest of the garden. Chicken manure is high in phosphates and too much can inhibit beneficial microbes in the soil. It also feeds the weeds. They love it. A better method would be to cover a layer of compost or composted horse or steer manure with a thick 4 inch layer of wood chips.

You’ll be amazed at the difference in your garden this season. A mulched garden is a happy garden. And if you have ivy, berries or vinca you want to eradicate, sheet mulching is the way to go. Next week I’ll go over the basics and share some success stories.

Design trends

Garden Inspiration at the Gamble Garden Tour

Picture your friends and family around this inviting fire pit.

Looking at your yard and thinking “This year I’m finally going to make some changes and enjoy my garden more.”? Take my advice: go on a garden tour for inspiration. Even a visit to a neighbor’s beautiful garden will work to get your creative juices going and motivate you. I do have to say that the gardens I visited recently in Palo Alto were spectacular. Definitely “the garden of my dreams” and I may just have to practice what I preach in my own little space.

While some of the gardens were clearly out of my price range – this was Palo Alto remember – there were elements from every one that I could imagine in a regular garden around here.

Everybody’s garden looks the best in the spring. Plants are full of new, healthy growth and the heat of summer has not yet descended. Early flowering plants are at their peak and those that wait until summer to flower so that their nectar will attract hummingbirds, butterflies and bees are patiently awaiting their time in the sun. It’s a glorious time in the garden.

This strip between sidewalk and street is solved here with succulents.

Because The Gamble Garden Spring Tour is a walking tour I got as many ideas from the gardens featured as I did passing by the front yards of the other houses. This is the neighborhood where Steve Jobs used to live.
The theme of the garden tour, Garden are for Living, came through loud and clear in each of the gardens. Many featured sustainable features such as a decomposed granite patio, poured in place concrete pavers, corten steel raised beds and path edging and dry laid flagstone paths. Edibles were included in every garden- from a grape-covered pergola to a cleverly designed raised veggie bed complete with steel corners and banding and lighting for evening dinner harvesting.

While walking the neighborhood a low water use plant combination of ornamental olive trees under-planted with rosemary and Iceberg roses complemented one Mediterranean style home. Another garden nearby featured a rustic fence made from fallen tree branches. I must have taken a hundred pictures to remind me of all the great design ideas I saw that day. The gardens were very approachable. Most are maintained mostly by the homeowners.

Many of us have meandering paths in our gardens separating the different garden rooms. The elements of garden design, like arrangement of paths, planting beds and open spaces, shape your garden. Your eye is drawn along a path through a garden. The plantings along the sides serve to frame but it’s the style of the path itself that enhances your experience in the garden. Some of the paths can be gravel, some walkable ground covers with pavers, some flagstone. All draw the visitor deeper into the garden to explore and linger at each spot.

Over the years I have gotten lots of inspiration from other gardens and tours. Valley Churches has held several fundraiser garden tours. I remember how fun it was to see the Enchanted Gardens of the Valley which was in San Lorenzo Valley one year, in Scotts Valley only a few years ago and one in Bonny Doon quite a while ago. On each of these tours I knew some of the garden owners and had spent time in each. Also I’ve gotten inspiration from visiting Camp Joy and everybody loves Filoli Gardens as well as Hikone Garden in Saratoga.

So go outside in your own garden and imagine the changes – big and small – that would make it spectacular.